The effect of partial-thickness facial burns on social functioning

The impact of partial-thickness facial burns on the behavior of adults was investigated. Burn injuries of the face often have a deleterious effect on the psychologic well-being of the patient. Even when no skin grafting is performed, there seems to be significant deterioration of the physical and emotional function of adults after they have incurred partial-thickness burns of the face.

IL-12 administered during Chlamydia psittaci lung infection in mice confers immediate and long-term protection and reduces macrophage inflammatory protein-2 level and neutrophil infiltration in lung tissue

Protection against infections with the intracellular bacterium Chlamydia spp. requires Th1-polarized CD4+ T cell immunity. In BALB/c mouse lung infections, immediate innate and nascent Chlamydia-specific immune responses following intranasal inoculation of Chlamydia psittaci strain B577 were modulated by 7-day i.p. administration of murine rIL-12, the initiation cytokine for Th1 immunity. Treatment with IL-12 reduced the severity of chlamydial pneumonia, abolished mortality (37.5% in untreated mice), and significantly reduced numbers of chlamydial organisms in lungs. On day 4 after inoculation, the neutrophil:macrophage ratio in bronchointerstitial pneumonias was 1.96 in untreated mice and 0.51 in IL-12-treated mice. This immediate, IL-12-mediated shift in innate inflammatory phenotype was correlated with a significant reduction of lung concentrations of the neutrophil chemoattractant macrophage inflammatory protein (MIP)-2 (putative murine homologue of human IL-8), monocyte chemotactic protein-1, and TNF-alpha; and a reduction in MIP-1alpha and IFN-gamma, at high-dose infection only, and IL-12-independent IL-10 levels. Chlamydia-specific Ab titers and Ig isotype ratios indicated an IL-12-dependent Th1 shift. Recall responses of IL-12-primed mice to secondary chlamydial lung infection eliminated chlamydiae more effectively and generated a lung cytokine profile conducive to perpetuation of the Th1 memory population. These data support the hypothesis that genetic differences in endogenous IL-12 production and response pathways could determine disease outcomes characterized by poor chlamydial clearance and a purulent inflammatory infiltrate vs effective elimination of chlamydiae in a macrophage-dominated response.

[Expression of xylose isomerase gene(xylA) in Saccharomyces cerevisiae from Clostridium thermohydrosulfuricum]

The Clostridium thermohydrosulfuricum xylA gene encoding xylose(glucose) isomerase was cloned in the yeast expression vector pMA91 under the control of the PGK promoter, resulting in pBX-1, and transformed into Saccharomyces cerevisiae. Production of recombinant xylose isomerase was seen in the a Coomassie stained SDS-PAGE gel and the molecular mass was estimated to be 43 kD. The recombinant xylose isomerase showed the highest activity at 85 degrees C and pH7. The specific activity under these condition was 1.0 U/mg protein. At 30 degrees C and 40 degrees C, the relative activity was reduced to 3.7% and 11%, respectively, of the maximum.

[The novel copolymer coated capillary columns of electrophoresis and their applications to separation of proteins]

The copolymer of acrylonitrile, methyl acrylate, hydroxy ethyl acrylate (ZB-004), the copolymer of acrylonitrile, methyl acrylate, hydroxy ethyl acrylate, acrylamide (ZB-014) and the copolymer of acrylonitrile, hydroxy ethyl acrylate (ZB-016) were coated on the inner surface of fused-silica capillaries by just filling the capillary with solutions containing these copolymers followed by flushing the capillary with nitrogen. The physically adsorbed layer can reduce both protein adsorption and electroosmotic flow in the pH range of 3-5. Electroosmotic flow decreased by raising the concentrations of the copolymers. Separation performance of ZB-004 layer is better than those of other two layers due to its low hydrophilicity, but with higher pH values, appreciable peak deformation and increase in electroosmosis were observed. The intra day and inter day migration reproducibility were investigated in terms of relative standard deviation (RSD) with four basic proteins at pH 4.0. The RSDs of the intra day migration times were less than 2%. The RSDs of the inter day migration times were less than 4%. At pH 5.0, the RSDs of the migration times in two ZB-004-coated capillaries made on two different days were less than 1%. Separation efficiencies of four basic proteins in a ZB-004-coated capillary which stored in a buffer (pH 4.0) for fifteen days after being used for 14 days decreased 15%. These coatings were stable and exhibited reproducible separations from intra day, inter day and inter column under acidic conditions.

Phase-contrast radiography

For the past 100 years, the paradigm for radiography has been premised on absorption as the sole means of contrast formation and on ray optics as the basis for image interpretation. A new conceptual approach to radiography has been developed that includes phase (ie, refractive) contrast and requires wave optics for proper treatment. This new approach greatly increases the amount of information that can be obtained with radiographic techniques and is particularly well suited to the imaging of soft tissue and of very small features in biologic samples. A key feature of the present technique of phase-contrast radiography is the use of a microfocus x-ray source about an order of magnitude (< or = 20 microm) smaller than that used in conventional radiography. Phase-contrast radiography offers a number of improvements over conventional radiography in a clinical setting, especially in soft-tissue imaging. These improvements include increased contrast resulting in improved visualization of anatomic detail, reduced absorbed dose to the patient, inherent image magnification and high spatial resolution, use of harder x rays, and relative ease of implementation. More technologically advanced detectors are currently being developed and commercialized, which will help fully realize the considerable potential of phase-contrast imaging.

Protective effects of baicalein against cell damage by reactive oxygen species

Baicalein (5,6,7-trihydroxy-2-phenyl-4H-1-benzopyran-4-one), a naturally occurring flavonoid, was found to prevent human dermal fibroblast cell damage induced by reactive oxygen species such as hydrogen peroxide (H2O2), tert-butyl hydroperoxide (BuOOH) and superoxide anions (.O2-) in a concentration-dependent manner, and was more effective than the iron chelator, deferoxamine, hydroxyl radical (.OH) scavengers such as dimethyl sulfoxide (DMSO) and ethanol (EtOH), the lipid peroxidation chain blocker, alpha-tocopherol (Vit. E) and the xanthine oxidase inhibitor, allopurinol. To probe the mechanism of cell defense, the reaction of baicalein with oxygen free radicals was investigated using electron spin resonance (ESR) spectrometry. Baicalein decreased the signal intensities due to the 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) spin adducts of .OH, .O2- and tert-butyl peroxyl (BuOO.) radicals in a concentration-dependent manner. The IC50 values, which are the 50% inhibition concentrations of baicalein for the free radicals, were 10, 45 and 310 microM, respectively. These results suggested that baicalein possesses free radical scavenging ability which prevents the fibroblast damage induced by these free radical species.

[Cell density and expression of proliferating cell nuclear antigen (PCNA) in the lens epithelium of children and aging patients with cataract]

OBJECTIVE

To determine the cell density and expression of proliferating cell nuclear antigen (PCNA) in the lens epithelium of children and aging patients with cataract.

METHODS

The lens epithelial cells (LECs) of the central area were examined in two groups, children (less than 12 years old) and senile persons (51 - 80 years old). The densities of LECs in the two groups were calculated with samples stained with hematoxylin and eosin (HE) staining, and the PCNA was tested immunohistochemically. The integral optical density (IOD) of PCNA expression was measured through a medical color image analysis system.

RESULTS

The densities of LECs in children and senile persons were 5,020.25 +/- 246.01 cells/mm(2) and 4,340.00 +/- 240.95 cells/mm(2) (P < 0.05), the IODs were 2.89 +/- 0.57 and 2.13 +/- 0.63 (P < 0.05) respectively.

CONCLUSION

The LEC counting and IOD values in children eyes are significantly higher than that of senile persons, suggesting that they be one of the important factors in the formation of posterior capsular opacification (PCO) or after cataract in children eyes.

The gene 4 of rice yellow stunt rhabdovirus encodes the matrix protein

The complete nucleotide sequence of the gene 4 of rice yellow stunt rhabdovirus (RYSV) was determined from cDNAs corresponding to the viral genomic RNA. Gene 4 is 913 nucleotides (nt) long, comprising a 17-nt untranslated 5' region, a 786-nt open reading frame encoding a polypeptide with a molecular mass of 29,125 Da, and a 110-nt untranslated 3' region. Western blot analysis of the RYSV proteins using the antiserum raised against the protein expressed from the cloned gene in Escherichia coli indicates that gene 4 encodes the M protein of RYSV. Comparisons of the deduced amino acid sequence of the M protein of RYSV with those of other rhabdoviruses revealed no significant homologies. However, it shared a similar basic property and a similar distribution of charges with the other rhabdovirus matrix proteins and showed a relatively closer relationship to the sonchus yellow net virus (SYNV) M1 protein.

Expression of the extracellular domain of the human immunodeficiency virus type 1 envelope protein and its fusion with beta-galactosidase in Saccharomyces cerevisiae

Two envelope glycoprotein gene fragments were cloned from the proviral genome of the HXB2 isolate of human immunodeficiency virus (HIV). For the production of the two domains of the envelope gene product these cloned gene fragments were inserted into an Escherichia coli-yeast inducible shuttle vector fused to the galactokinase (GAL1) promoter. Cell extracts from strains of Saccharomyces cerevisiae harboring these two vectors (pYENV1 and pYENV2) were found to contain a specific protein with a size of 50 kDa when induced by galactose, while the protein could not be detected in extracts from control cells containing only the E. coli-yeast vector in the presence of galactose. Furthermore, another expression plasmid coding for fusion proteins from the majority of the external envelope glycoprotein (gp120) moiety and a large part of the beta-galactosidase was constructed. Antibodies from HIV type 1-positive sera could react with recombinant fusion polypeptides. Transformants could produce this fusion protein to a level of about 1.6% of the total protein content, as deduced from beta-galactosidase activity.

Binding affinity of Cu(II)-VP-16 (etoposide) complex and its analogues to DNA and hydroxyl radical generation during DNA strand breaks

Conformational effects and affinities of VP-16 (etoposide) and its derivatives to DNA in the presence of Cu(II) ion were examined by circular dichroic (CD) spectra. The Cu(II)/Cu(I) redox kinetics and the hydroxyl radical (.OH) generation from the Cu(II)-complexes were estimated by the stopped-flow kinetics. Based on the results, DNA-cleaving activity of Cu(II)-complexes of VP-16 has been shown to be related with binding affinity of the complex to DNA, Cu(II)/Cu(I) redox and .OH generation, emphasising the mechanism of generated .OH attack to DNA.

[Long-term results of combined splenorenal shunt and porta-azygos devascularization in patients with portal hypertension]

OBJECTIVE

To investigate the long-term effects of combined splenorenal shunt and porta-azygos devascularization in patients with portal hypertension.

METHOD

We analysed retrospectively the follow-up results of 140 portal hypertensive patients undergoing the combined therapy in our hospital from April 1978 to April 1997. Changes of portal hemodynamics were studied by Doppler Flowmeter and DSA pre- and-postoperatively and direct FPP measurement intraoperatively.

RESULT

The operative mortality was 3.6%. No rebleeding was noted in a short period and rebleeding rate was 8.3% in a long term follow-up. The rate of postoperative hepatic encephalopathy was 5.0%. The long-term survival rate of 5-, 10- and 15-years was 83.6%, 64.5% and 54.5%, respectively. After operation FPP and PVP decreased significantly (P < 0.01) and FPP maintained at the level of 3.2 +/- 0.4 kPa.

CONCLUSION

The combined procedure is a rational and practical procedure for the treatment of patients with portal hypertension.

[Comparative research on two different killer strains of Saccharomyces cerevisiae]

Using two different killer strains SK4(K1 type) and ERR1(K2 type), their killer characters were analysed and find two strains compete with each other when they are mixed and killer characters are related with the growth of strains. Different M-dsRNA plasmids in different killer strains have different molecular lengths, being 1.7 kb and 1.5 kb in SK4 and ERR1, respectively. L-dsRNA plasmids in both strains have the same molecular lengths, 4.0 kb. Cured by high temperature (38 degrees C) and U.V. (15 W, 30 cm, 5 min), killer strains lose their killer characters with the disappearance of M-dsRNA, the curing rate of killer activity is associated with strains and curing conditions. Killer toxins produced by two strains have different killer effects. Toxins of SK4 and ERR1 have the different highest killer activity at pH 4.8, 16 degrees C and pH4.2, 22 degrees C, but both of two toxins have the greatest effect on the sensitive strain in the late-log phase.

[The timing and mode of surgery in patients with severe acute pancreatitis]

OBJECTIVE

To investigate the timing and mode of surgical management in patients with severe acute pancreatitis (SAP).

METHOD

The timing, mode of operation and mortality were reviewed retrospectively in 50 SAP cases undergoing laparotomy in our hospital from 1985 to 1994.

RESULT

The overall mortality was 14% and 85.7% of the mortality falls on the age between 40 to 60 years, with no difference in etiology and sex. The operative mortality reduced gradually in patients with longer duration of illness (P > 0.05). The operative mortality of 31.8% in patients undergoing laparotomy within 12 h after hospitalization was significantly higher (P < 0.05) than in these operated on later. When the number of injured extra-pancreatic organs increased, the mortality also increased significantly (chi(2) = 5.99, P < 0.05). The related mortality with shock, pancreatic necrosis and multiorgan failure (MOF) was 31.8%, 31.6% and 28%, respectively (P < 0.05). The main procedures of surgical management were pancreatic debridement and/or drainage, and combined surgical measures.

CONCLUSION

The laparotomy timing is an important factor influencing mortality as well as the severity of pancreatic necrosis, sepsis, and MOF. Delayed laparotomy and 24 h preoperative management is recommended. Surgery adopted should be simple, efficient in drainage and debridement.

Intermolecular Force-Field Parameters for Boron Hydrides

Intermolecular atom–atom force-field parameters of the (exp-6-1) type for B and H atoms in boron hydrides were determined. They were obtained by full-weighted least-squares minimization of 116 forces in 15 observed crystal structures of boranes, the heat of sublimation of B10H14 and data from ab initio wavefunction calculations for diborane. Net atomic charges were obtained by fitting them to molecular electric potentials calculated from ab initio wavefunctions. Charges of terminal hydrogens were usually negative and those of bridging hydrogens usually positive. Repulsion-energy calculations for the B2H6 dimer provided the exponential dependence of H...H repulsion. Using the resulting force field, minimum-energy crystal structures were found with structural parameter values close to those of the observed structures. For diborane, energy minimization beginning with randomly oriented molecules placed initially in an 8 × 8 × 8 body-centered orthogonal cell led to the observed crystal structure and monoclinic space group.

[An experimental study on effects of biomembrane on prevention of filtering bleb adhesion in trabeculectomy]

OBJECTIVE

The study was designed to investigate the effects of biomembrane on experimental trabeculectomy.

METHODS

A biomembrane was implanted under the scleral flap and the conjunctival flap in trabeculectomy in one eye of rabbits, while the fellow eye of the same rabbit without biomembrane implantation was the control.

RESULTS

(1) The wound healing of the procedure reached its peak at 2-3 weeks after surgery, while the absorption of the biomembrane began at 6 weeks after surgery, and there was no tight adhesion between the biomembrane and the scar tissue, thus the filtering fistula was prevented from obstruction. (2) From the 2nd to the 7th week after surgery, the percentage of existing functional bleb in the experimental group was significantly higher than that in the control group (P < 0.05). (3) From the 1st to the 5th postoperative week, the decreasing of intraocular pressure in the experimental group was significantly greater than that in the control group (P < 0.05).

CONCLUSION

The use of biomembrane in trabeculectomy can prevent the adhesion of filtering bleb and decrease intraocular pressure more effectively, and this study can provide experimental reference for the clinical use of biomembrane.

Water and DMSO membrane permeability characteristics of in-vivo- and in-vitro-derived and cultured murine oocytes and embryos

Although embryo cryopreservation is routine for many mammalian species, it is important to know how the fundamental cryobiology of these cells changes with development. Progressive cleavage divisions result in a reduction in the blastomere surface area available for water and cryoprotectant mass transport. Therefore, the membrane permeability of murine oocytes, zygotes, 2-cell, 4-cell, and 8-cell embryos to water (Lp), and dimethylsulphoxide (PDMSO), and the reflection coefficient, sigma (sigma) were determined. Oocytes or zygotes were recovered, cumulus cells removed, then cultured until use. Oocytes and embryos were immobilized and perfused with treatment solutions at 24 degrees C. Osmotically induced cell volume changes over time were videotaped followed by image analysis. The Lp values in the presence of dimethylsulphoxide (DMSO) were 0.77, 0.81, 0.94, 0.86, and 1.10 microm/min/atm, and the PDMSO values were 1.85, 2.04, 2.41, 1.95, and 1.25x10(-3) cm/min for oocytes, zygotes, 2, 4, and 8-cell embryos respectively. The Lp values in the presence of DMSO were significantly (P < 0.05) higher than those in the absence of DMSO. Treating the whole embryo as a single osmotic entity leads to significantly (P < 0.05) elevated PDMSO estimates relative to those based upon measurements of individual blastomeres. These data indicate that both Lp and PDMSO estimates are lower when predicted on an individual blastomere basis. The data also show that neither Lp nor PDMSO differ among oocytes, zygotes, 2-cell and 4-cell embryos. However, the significantly higher Lp and lower PDMSO of the 8-cell stage support the hypothesis that fundamental cryobiological differences may require developmental stage-specific embryo cryopreservation protocols.

Functional domains of LAG-2, a putative signaling ligand for LIN-12 and GLP-1 receptors in Caenorhabditis elegans

The LAG-2 membrane protein is a putative signaling ligand for the LIN-12 and GLP-1 receptors of Caenorhabditis elegans. LAG-2, like its Drosophila homologues Delta and Serrate, acts in a conserved signal transduction pathway to regulate cell fates during development. In this article, we investigate the functional domains of LAG-2. For the most part, mutants were constructed in vitro and assayed for activity in transgenic animals. We find a functional role for all major regions except one. Within the extracellular domain, the N-terminal region, which bears no known motif, and the DSL domain are both required. By contrast, the region bearing epidermal growth factor-like repeats can be deleted with no apparent reduction in rescuing activity. The intracellular region is not required for activity but instead plays a role in down-regulating LAG-2 function. Finally, membrane association is critical for mutant rescue.

Roles of GABA, glutamate, acetylcholine and STN stimulation on thalamic VM in rats

The effects of high frequency stimulation of the subthalamic nucleus (STN) and of iontophoretic application of different neurotransmitters on neuronal activities of the ventromedial thalamic nucleus (VM) were investigated in rats. GABA, when applied iontophoretically, inhibited VM neuronal activity while bicuculline, L-glutamic acid and acetylcholine enhanced the firing rates of the same VM neurons. High frequency stimulation of the STN increased VM neuronal activity in a frequency-dependent manner, which could be blocked by MK801. These results suggest that GABAergic, cholinergic and glutamatergic input information converge in the same VM neurons and that an increase in the delivery of glutamatergic neurotransmitter activities in the VM is involved in the process of high frequency stimulation of the STN.

Solidification Processes of Solutions

Recent progress in modeling pure liquid and dendritic alloy solidification is reviewed to lay the groundwork for freezing of solutions relevant to cryopreservation of biological materials. The classical Stefan problem of freezing/melting a pure substance is discussed first to introduce some of the fundamental concepts, and then the framework for modeling the freezing of solutions is reviewed. The formalism is extended to the freezing of a solution-saturated porous media. As an application of the methodologies developed by engineers, freezing of a sodium chloride solution in a flat bag is simulated, and then using the temperature and salt concentration data calculated the kinetics of water loss from a model cell is predicted.

Novel microwave technology for cryopreservation of biomaterials by suppression of apparent ice formation

Ice formation inside or outside cells has been proposed to be a factor causing cryoinjury to cells/tissues during cryopreservation. How to control, reduce, or eliminate the ice formation has been an important research topic in fundamental cryobiology. The objective of this study was to test a hypothesis that the coupled interaction of microwave radiation and cryoprotectant concentration could significantly influence ice formation and enhance potential vitrification in cryopreservation media at a relative slow cooling rate. Test samples consisted of a series of solutions with ethylene glycol (a cryoprotectant) concentration ranging from 3 to 5.5 M. A specific microwave resonant cavity was built and utilized to provide an intense oscillating electric field. Solutions were simultaneously exposed to this electric field and cooled to -196 degrees C by rapid immersion in liquid nitrogen. Control samples were similarly submerged in liquid nitrogen but without the microwave field. The amount of ice formation was determined by analysis of digital images of the samples. The morphology of the solidified samples was observed by cryomicroscopy. It was found that ice formation was greatly influenced by microwave irradiation. For example, ice formation could be reduced by roughly 56% in 3.5 M ethylene glycol solutions. An average reduction of 66% was observed in 4.5 M solutions. Statistical analysis indicated that the main effects of microwave and ethylene glycol concentration as well as the interaction between these two factors significantly (P < 0.01) influenced ice formation amount, confirming the hypothesis. This preliminary study suggests that a combined use of microwave irradiation and cryoprotectant might be a potential approach to control ice formation in cells/tissues during the cooling process and to enhance vitrification of these biomaterials for long-term cryopreservation.

[Influences of acetylcholine, glutamic acid and GABA on the neuronal firings in ventromedial thalamic nucleus]

In this study, it was shown that the neuronal spontaneous firings of ventromedial thalamic nucleus (VM) in rats were increased by acetylcholine (ACH) and glutamic acid (GLU) applied microiontophoretically with an intensity-dependent manner. Both gamma-animobutyric acid (GABA) and baclofen inhibited the spontaneous firings in majority of VM neurons, but the effect of GABA was rapid and short-lasting, while that of baclofen was slow and long-lasting. GABA could reverse the effects of ACH and GLU. The majority of VM neuronal firing rates could be enhanced by bicuculine, while atropine and MK801 had little effect. The results indicate an important convergence of GLUergic, GABAergic and cholinergic activities in the same VM neurons and GABAergic activities tonically inhibit the VM neurons.

Structure and transcription of the gene for translation elongation factor 1 subunit alpha of zebrafish (Danio rerio)

The zebrafish gene for translation elongation factor 1 alpha (EF1 alpha) was isolated from a phage Lambda genomic library and sequence and structure determined. One gene copy of EF1 alpha per haploid set of chromosomes was found and no processed pseudogenes. A highly active promoter region was localized to a 277 bp PstI/PvuII fragment beginning 240 bp upstream from the tsp, but no transcription enhancing, or silencing activity was observed within 1 kbp upstream, or downstream from the promoter. Expression of EF1 alpha appears to be developmentally regulated.

Effect on product formation in recombinant Saccharomyces cerevisiae strains expressing different levels of xylose metabolic genes

The XYL1 and XYL2 genes from Pichia stipitis encoding xylose reductase (XR) and xylilitol dehydrogenase (XDH), respectively, were transformed into Saccharomyces cerevisiae. These two genes were placed in different directions under the control of the alcohol dehydrogenase I (ADHI) and phosphoglycerate kinase (PGK) promoters and inserted into the E. coli-yeast shuttle plasmid YEp24. Different recombinant S. cerevisiae strains were constructed with different specific activities of XR and XDH. The highest XR or XDH activities were obtained when the expressed gene was controlled by the PGK promoter and located downstream after the ADHI promoter-gene-terminator sequence. The XR/XDH ratio (ratio of specific enzyme activities of XR and XDH) in these recombinant S. cerevisiae strains varied from 17.5 to 0.06. In order to enhance xylose utilization, in the XYL1, XYL2 containing S. cerevisiae strains, the native TKL1 gene encoding transketolase and the TALI gene encoding transaldolase were also overexpressed, which showed considerably good growth on the xylose plate. Fermentation of the recombinant S. cerevisiae strains containing XYL1, XYL2, TKL1, and TAL1 were studied with mixtures of glucose and xylose. The strain with XR/XDH ratio of 0.06 consumed 3.25 g/L xylose and formed no xylitol and less glycerol and acetic acid, but more ethanol compared with the strains with a higher XR/XDH ratio.

Zebrafish translation elongation factor EF1 alpha mRNA: sequence and secondary structures

We have determined the complete sequence of the translation elongation factor EF1 subunit alpha (EF1 alpha) mRNA of zebrafish, and the 3'-untranslated sequence of EF1 alpha mRNA of halibut. The 5'-untranslated leader sequence of the EF1 alpha mRNA starts with a polypyrimidine tract. This feature is shared with the mRNAs for ribosomal proteins, where it affects the utilization of mRNA by ribosomes. However, the secondary structures of these leader sequences may differ. 5'-Polypyrimidine tracts of vertebrate EF1 alpha mRNAs participate in the formation of stable stem-loop structures, whereas those of 15 randomly chosen mRNAs for ribosomal proteins do not. This difference may provide a basis for differential control of translation for the two classes of mRNA. The 3'-untranslated sequences of vertebrate EF1 alpha mRNA have diverged little during evolution. Analyses of sequence and putative secondary structures suggest that both sequence-specific interactions and secondary structures may have contributed to sequence conservation.

Inhibition of microsomal lipid peroxidation by baicalein: a possible formation of an iron-baicalein complex

Baicalein decreased the production of thiobarbituric acid reactive substances, the rate of oxygen consumption and iron reduction in the reaction system of ascorbic acid with FeCl3. Superoxide dismutase, catalase and hydroxyl radical scavengers had no significant effect. Iron-chelators had an inhibitory effect similar to that of baicalein. The production of thiobarbituric acid reactive substances of baicalein-treated microsomes obtained by centrifugation after incubation with baicalein was not observed in the reaction system, but was stimulated by adding iron with increases in concentration. The amount of bound iron to microsomal membranes increased by increasing both the concentration of baicalein and iron. The amount of baicalein bound to microsomal membranes increased with increasing concentration of added baicalein. These results suggest that baicalein bound to microsomal membranes inhibits lipid peroxidation by formating an iron-baicalein complex.

[Angioimmunoblastic lymphadenopathy and angioimmunoblastic T-cell lymphoma]

To investigate the clinicopathological changes of angioimmunoblastic lymphadenopathy (AILD) and angioimmunoblastic T-cell lymphoma (AITL), 5 cases of AILD and AITL were analyzed by using immunohistochemistry and Polymerase chain reaction (PCR) methods. The clinical manifestations included general lymphadenopathy, hepatosplenomegaly, fever and hematologic abnormalities. The diagnosis and differentiation of AILD and AITL were depended on the histopathologic features of lymphnodes biopsy. The presence of clusters of clear cells with variable atypia and positivity of T-cell marker were the most important diagnostic criterion for AITL. PCR analysis of TCR-beta rearrangement and EBV-genome was performed on 4 of 5 cases. All of the cases showed clonal rearrangement of TCR-beta and 3 of them were EBV-DNA positive. The results suggest that AILD might be a prelymphomatous lesion, related to EBV infection with a high incidence of developing to malignant lymphoma.

[Study on the interrelationship between human papilloma virus infection and Langerhans cell in carcinogenesis of esophagus]

In order to find out the interrelationship between human papilloma virus (HPV) infection and Langerhans cells (LCs) during the development of esophageal carcinoma, and the mechanism of carcinogenesis during HPV infection, digoxigenine labelled HPV DNA probes of HPV 6B/11, HPV 16/18 with in situ hybridization, and anti-S-100 protein antibody with immunohistochemical LSAB-assays were used respectively in order to investigate HPV infection and the distribution of LCs in 40 cases of esophageal squamous cell carcinoma (ESCC). The results showed that there were fewer LC infiltration in HPV-positive cases in comparison with that of the HPV-negative cases. There were also changes about the morphology and distribution of LCs in HPV infected epithelia adjacent to the tumor. The results indicated that HPV infection might inhibit the number of locally LCs infiltrated, destroy the immune surveillance system, and work simultaneously with other carcinogenic factors, in favor of the development of ESCC.

Chronic electrical stimulation of the ventralis intermedius nucleus of the thalamus as a treatment of movement disorders

Tremor was suppressed by test stimulation of the thalamic ventralis intermedius (VIM) nucleus at high frequency (130 Hz) during stereotaxy in nonanesthetized patients suffering from Parkinson's disease or essential tremor. Ventralis intermedius stimulation has since been used by the authors over the last 8 years as a treatment in 117 patients with movement disorders (80 cases of Parkinson's disease, 20 cases of essential tremor, and 17 cases of various dyskinesias and dystonias including four multiple sclerosis). Chronic electrodes were stereotactically implanted in the VIM and connected to a programmable stimulator. Results depend on the indication. In Parkinson's disease patients, tremor, but not bradykinesia and rigidity, was selectively suppressed for as long as 8 years. Administration of L-Dopa was decreased by more than 30% in 40 Parkinson's disease patients. In essential tremor patients, results were satisfactory but deteriorated with time in 18.5% of cases, mainly for patients who presented an action component of their but deteriorated with time in 18.5% of cases, mainly for patients who presented an action component of their tremor. In other types of dyskinesias (except multiple sclerosis), results were much less favorable. Fifty-nine patients underwent bilateral implantation and 14 other patients received implantation contralateral to a previous thalamotomy. Thirty-seven patients (31.6%) experienced minor side effects, which were always well tolerated and immediately reversible. Three secondary scalp infections led to temporary removal of the implanted material. There was no permanent morbidity. This tremor suppression effect could be due to the inhibition or jamming of a retroactive loop. Chronic VIM stimulation, which is reversible, adaptable, and well tolerated even by patients undergoing bilateral surgery (74 of 117 patients) and by elderly patients, should replace thalamotomy in the regular surgical treatment of parkinsonian and essential tremors.

Osmotic separation of pancreatic exocrine cells from crude islet cell preparations

A novel approach is introduced here to selectively lyse exocrine cells in an islet preparation by hypo-osmotic treatment. Time to hypotonic cell lysis required for the islet cells was much longer than that for the exocrine cells, which permits a possibility of selectively killing the exocrine cells by hypotonic treatment. The first set of experiments was designed to select an appropriate osmolality for the hypotonic treatment. Kinetic changes in cell volume in response to extracellular anisosmolalities (30 to 90 mOsm/kg) were recorded using an electronic particle counter. The results indicated that, when exposed to a 30 mOsm/kg solution, islet cells swelled slowly to reach volumetric equilibrium in approximately 3 min. There was no significant hypotonic cell lysis observed even at the end of 4 min (n = 4). In contrast, pancreatic exocrine cells, when exposed to the same solution, expanded rapidly to the lytic volume and burst within 30 s. Significant exocrine cell lysis was invariably achieved within 30 s when cells were exposed to the osmolalities below 60 mOsm/kg. For osmolalities between 70 to 80 mOsm/kg, exocrine cell lysis was highly variable. When cells were exposed to 80 to 90 mOsm/kg, no significant cell lysis was observed. Thus, an osmolality of 50 mOsm/kg is recommended for hypotonic treatment, as it maximizes the lysis of exocrine cells without unnecessarily stressing (osmotically) the islet cells. The second set of experiments (time-course experiments, 20 to 120 s) was designed to determine the length of exposure time for which the exocrine cells were irreversibly damaged but the islet cells had only swollen to such a degree that cell function is restored upon returning to an isotonic condition. Viability of the hypotonic treated cells was evaluated at two different levels: membrane integrity, measured by combined fluorescent dye staining with propidium iodide (PI) and carboxyfluorescein diacetate (CFDA), and mitochondrial function, measured by colorimetric MTT assay. The results showed that hypotonic treatment in a 50 mOsm/kg solution for 30 s resulted in over 85% loss of the membrane integrity for the exocrine cells. About 90% of these membrane lysed cells lost mitochondrial function (n = 3). By contrast, under the same treatment, less than 15% of the islet cells lost membrane integrity and mitochondrial function (n = 3). In conclusion, hypotonic treatment with a 50 mOsm/kg solution for 20 to 30 s at room temperature is sufficient to lyse the majority of the contaminating exocrine cells in an islet cell preparation, while maintaining function in the islet cells.

Recovery from spinal cord injury mediated by antibodies to neurite growth inhibitors

There is little axonal growth after central nervous system (CNS) injury in adult mammals. The administration of antibodies (IN-1) to neutralize the myelin-associated neurite growth inhibitory proteins leads to long-distance regrowth of a proportion of CNS axons after injury. Our aim was: to determine if spinal cord lesion in adult rats, followed by treatment with antibodies to neurite growth inhibitors, can lead to regeneration and anatomical plasticity of other spinally projecting pathways; to determine if the anatomical projections persist at long survival intervals; and to determine whether this fibre growth is associated with recovery of function. We report here that brain stem-spinal as well as corticospinal axons undergo regeneration and anatomical plasticity after application of IN-1 antibodies. There is a recovery of specific reflex and locomotor functions after spinal cord injury in these adult rats. Removal of the sensorimotor cortex in IN-1-treated rats 2-3 months later abolished the recovered contact-placing responses, suggesting that the recovery was dependent upon the regrowth of these pathways.

APX-1 can substitute for its homolog LAG-2 to direct cell interactions throughout Caenorhabditis elegans development

The homologous LAG-2 and APX-1 membrane proteins are putative signaling ligands in the GLP-1/LIN-12 signal-transduction pathway in Caenorhabditis elegans. Normally, LAG-2 and APX-1 mediate distinct cell interactions. Here, we demonstrate that APX-1, which normally interacts with GLP-1 in the early embryo, can substitute for LAG-2 throughout development. When expressed under control of the lag-2 promoter, an apx-1 cDNA can completely rescue a lag-2 null mutant. To substitute for LAG-2, APX-1 must be able to interact with both GLP-1 and LIN-12 receptors and to mediate a variety of cell interactions during development. Therefore, APX-1 and LAG-2 are essentially equivalent in their ability to influence receptor activity. On the basis of this result, we suggest that the existence of multiple-signaling ligands in the LIN-12/GLP-1 signal transduction pathway does not reflect the evolution of functionally distinct proteins but rather the imposition of distinct controls of gene expression upon functionally similar proteins. Finally, we propose that the specification of distinct cell fates by the LIN-12/GLP-1 signal-transduction pathway relies on activities functioning downstream of the ligand and receptor, rather than on specific ligand-receptor interactions.

Protection by baicalein against ascorbic acid-induced lipid peroxidation of rat liver microsomes

The effect of baicalein (5,6,7-trihydroxy-2-phenyl-4H-1-benzopyran-4-one), a flavonoid isolated from Scutellaria baicalensis Georgi, on lipid peroxidation in rat liver microsomes was studied. Ascorbic acid-induced lipid peroxidation in microsomes obtained from baicalein-treated rats was inhibited by treatment on different days and at different doses. Iron release induced by ascorbic acid from microsomes of baicalein-treated rats was markedly lower than from microsomes of control rats. However, no statistical differences in total, nonheme and nonprotein-bound (free iron) iron contents could be detected in the two microsomes. The degradation of calf thymus DNA, an indicator of free iron existence, was observed in the reactions of microsomes obtained from control and baicalein-treated rats with ascorbic acid in the presence of bleomycin. These results suggest that baicalein can inhibit lipid peroxidation in microsomes induced by ascorbic acid by forming an inert complex of iron.

Water permeability and its activation energy for individual hamster pancreatic islet cells

Coupled with the rapid development of clinical pancreatic islet transplantation, there is an increasing requirement for cryopreservation of viable islets. Fundamental cryobiology requires determination of several cryobiophysical parameters to predict optimal cryopreservation procedures. These include water permeability or hydraulic conductivity (Lp) and its activation energy (Ea), the permeability of the cell plasma membrane to a cryoprotectant(s) (Ps) and its Ea, the osmotically inactive fraction of cell volume (Vb), and the intracellular ice formation temperature. For islet cells, these parameters have not previously been reported. In the present studies, the Lp, its Ea, and Vb were determined for isolated individual golden hamster pancreatic islet cells. The Lp and Vb parameters were also measured for corresponding exocrine cells. Both islet and the exocrine cells appeared to be ideal osmometers over the experimental range when examined by the Boyle Van't-Hoff relationship (linear regression, r = 0.99 for both types of cells). Extrapolation of these plots generated Vb values of 0.40 for the islet cells and 0.45 for the pancreatic exocrine cells. To determine the Lp, kinetic changes of cell volume over time (dv/dt) in response to anisoosmotic conditions (ranging from 145 mOsm/kg to 1.35 Osm/kg) were measured using an electronic particle counter. The experimental data were fitted to generate the Lp values by least-squares curve fitting to a differential equation describing osmotic water movement across the plasma membrane. For pancreatic islet cells, the Lp was determined to be 0.25 +/- 0.03 microns/min/atm (mean +/- SD, n = 14) at 22 degrees C, 0.54 +/- 0.07 (n = 10), 0.06 +/- 0.008 (n = 9), and 0.01 +/- 0.001 (n = 9) at 37, 8 and 0 degrees C, respectively. The Ea for Lp was calculated from the slope of the Arrhenius plot based upon the mean Lp values at the four different temperatures. The Ea was 16.21 Kcal/mol between 0 and 37 degrees C. Based upon these values, an optimal cooling rate for cryopreserving pancreatic islet cells is predicted to be approximately 0.5 degrees C min. The Lp for the individual exocrine cells was determined to be 3.73 +/- 1.75 microns/min/atm (n = 13) at 22 degrees C, which was approximately 10 times the Lp value of the corresponding islet cells.

High water permeability of human spermatozoa is mercury-resistant and not mediated by CHIP28

A novel integral membrane protein with an apparent molecular mass of 28 kDa (CHIP28) was first isolated from human erythrocytes and is now recognized as a water channel protein. The expression of this protein has been found in several other cell types that all require high water permeability for their functions. Recent studies have shown that the water permeability (Lp) of human spermatozoa is among the highest reported for mammalian cells. Together with the low activation energy of human spermatozoa for Lp, this suggests that CHIP28 water channel may be present in the plasma membrane of human spermatozoa. However, our current studies do not support this hypothesis. Results from Western blot analysis on human sperm plasma membrane proteins, performed through use of an antibody against human erythrocyte CHIP28 protein, indicated that human spermatozoa do not express CHIP28 protein on their cell surface (n = 10). Consistent with the Western blot finding, mercuric chloride (HgCl2), a known water channel blocker, failed to reduce the osmotic water permeability of human spermatozoa. The calculated Lp values were 1.30 +/- 0.29 micron/min/atm (n = 16; mean +/- SEM) for the control group and 1.31 +/- 0.29 (n = 9; mean +/- SEM), 1.04 +/- 0.27 (n = 11; mean +/- SEM), and 1.34 +/- 0.19 (n = 6; mean +/- SEM), respectively, for the 10 microM, 30 microM, and 50 microM HgCl2-treated groups. These Lp values are not different (p > 0.05). In contrast, the same concentration of HgCl2 significantly blocked the osmotic water transport across the membrane of human erythrocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

lag-2 may encode a signaling ligand for the GLP-1 and LIN-12 receptors of C. elegans

The C. elegans lag-2 gene is required for several cell-cell interactions that rely on the receptors GLP-1 and LIN-12. In this paper, we report that lag-2 encodes a putative membrane protein with sequence similarity to Drosophila Delta, a proposed ligand for the Notch receptor. Furthermore, we show that the lag-2 promoter drives expression of a reporter protein in the signaling distal tip cell (DTC) of the DTC/germline interaction. By in situ hybridization, we have found that endogenous lag-2 mRNA is present in the DTC but not the germ line. One fusion protein, called LAG-2::beta-gal(intra), rescues a lag-2 null mutant and can be detected in both DTC and germ line. Taking these results together, we propose that lag-2 may encode a signaling ligand for GLP-1/LIN-12 and that the entire LAG-2 protein may be taken up into the receiving cell during induction by GLP-1 and lateral signaling by LIN-12.

Characterization of the synthesis and expression of the GTA-kinase from transformed and normal rodent cells

The murine transformed cell line YC-8 and beta-adrenergic receptor agonist (isoproternol) treated rat and mouse parotid gland acinar cells ectopically express cell surface beta 1-4 galactosyltransferase during active proliferation. This activity is dependent upon the expression of the GTA-kinase (p58) in these cells. Using total RNA, cDNA clones for the protein coding region of the kinase were isolated by reverse transcriptase-PCR cloning. DNA sequence analysis failed to show sequence differences with the normal homolog from mouse cells although Southern blot analysis of YC-8, and a second cell line KI81, indicated changes in the restriction enzyme digestion profile relative to murine cell lines which do not express cell surface galactosyltransferase. The rat cDNA clone from isoproterenol-treated salivary glands showed a high degree of protein and nucleic acid sequence homology to the GTA-kinase from both murine and human sources. Northern blot analysis of YC-8 and a control cell line LSTRA revealed the synthesis of a major 3.0 kb mRNA from both cell lines plus the unique expression of a 4.5 kb mRNA in the YC-8 cells. Reverse transcriptase-PCR of LSTRA and YC-8 confirmed the increased steady state levels of the GTA-kinase mRNA in YC-8. In the mouse, induction of cell proliferation by isoproterenol resulted in a 50-fold increase in steady state mRNA levels for the kinase over the low level of expression in quiescent cells. Expression of the rat 3' untranslated region in rat parotid cells in vitro led to an increased rate of DNA synthesis, cell number an ectopic expression of cell surface galactosyltransferase in the sense orientation. Antisense expression or vector alone did not alter growth characteristics of acinar cells. A polyclonal antibody monospecific to a murine amino terminal peptide sequence revealed a uniform distribution of GTA-kinase over the cytoplasm of acinar and duct cells of control mouse parotid glands. However, upon growth stimulation, kinase was detected primarily in a perinuclear and nuclear immunostaining pattern. Western blot analysis confirmed a translocation from a cytoplasmic localization in both LSTRA and quiescent salivary cells to a membrane-associated localization in YC-8 and proliferating salivary cells.

Parasexual crosses and hybrid selection with a near haploid variant of the epithelioma papulosum cyprini, cell line EPC: a tissue culture model for the analyses of dominance, recessiveness, and complementation of mutant phenotypes

We describe techniques for insertional mutagenesis of tissue-cultured piscine cells in which we use transfection with G418 and hygromycin B resistance-conferring plasmids, cell matings by electrofusion, and positive selections of fusion hybrids by dual challenge with the antibiotics G418 and hygromycin B. These techniques are designed to facilitate genetic and molecular analyses of tissue-cultured cells. The experiments were conducted with EPC-1, a new variant of the carp epithelioma cyprini cell line. EPC, with a near haploid number of chromosomes, EPC-1 retains cell morphology and growth characteristics of EPC, including anchorage independence, but shows a higher degree of contact inhibition. The number of metaphase chromosomes of EPC-1 is 53, as opposed to 96 reported for EPC.

[Cloning and expression of beta-glucosidase gene in Xanthomonas campestris XA5-5]

A beta-glucosidase gene from Xanthomonas campestris XA5-5 was cloned in Escherichia coli with the broad-host-range plasmid pRK404. The beta-glucosidase encoding plasmid designated pLZS1 contained a 1.1kb PstI DNA fragment deriving from XA5-5. The plasmid pLZS1 was transconjugated by filter mating into XA5-5 producing homologous clones XA5-5(pLZS1). Plasmid stability analysis revealed that pLZS1 was more stable in XA5-5 than in E. coli JM83. The level of beta-glucosidase expressed in XA5-5 (pLZS1) was much higher than in E. coli JM83 (pLZS1) using salicin as the substrate. From the results obtained, it seems that the gene product of this cloned DNA fragment has higher affinity to salicin substrate, and in some sense reduces the affinity between the enzyme and pNPG substrate in XA5-5.

Cryopreservation of human spermatozoa. IV. The effects of cooling rate and warming rate on the maintenance of motility, plasma membrane integrity, and mitochondrial function

OBJECTIVE

To test the hypotheses that there is a two-factor aspect of cellular damage during cryopreservation that occurs in human sperm (osmotic effects versus intracellular ice formation) and that there is a cooling rate by warming rate interaction related to this damage.

DESIGN

Ejaculates from healthy men were cooled at 0.1, 1.0, 10, 175, or 800 degrees C/min to -80 degrees C in a solution of 0.85 M glycerol and plunged into liquid nitrogen. Samples were warmed at 400 degrees C/min (experiment 1) or either 1 degrees C or 400 degrees C/min (experiment 2). After warming, sperm were assessed for survival using motility as the endpoint in experiment 1 and motility, plasma membrane integrity, and mitochondrial function in experiment 2.

RESULTS

In experiment 1, over the various cooling rates with a standard 400 degrees C/min warming rate, a plot of motility versus cooling rate produced a classical inverted U-shaped curve (n = 6) with maximum motility at the 10 degrees C/min cooling rate. In experiment 2, over the various cooling rates, both 1 and 400 degrees C/min warming rates produced similar but shifted plots of motility, plasma membrane integrity, and mitochondrial function versus cooling rate, which also produced inverted U-shaped patterns (n = 11). Maximal survival for each of the three endpoints occurred at 10 degrees C/min cooling rate for the rapidly warmed sperm and at 1 degree C/min for the slowly warmed sperm.

CONCLUSIONS

These data support the hypotheses that a two-factor hypothesis of cryodamage applies to human spermatozoa and that an interaction exists between cooling rate and warming rate. These data also suggest that motility, plasma membrane integrity, and mitochondrial function are not differently affected by cooling and warming during cryopreservation.

Recovery of function after spinal cord injury: mechanisms underlying transplant-mediated recovery of function differ after spinal cord injury in newborn and adult rats

Fetal spinal cord transplants placed into the site of spinal cord injury support axonal growth of host systems in both newborn and adult animals. The amount of axonal growth, however, is much more robust in the newborn animals. The current studies were designed to determine if the differences in the magnitude of the anatomical plasticity of host pathways in the presence of transplants is reflected in differences in recovery of function between the neonatal and adult operates. Newborn and adult rats received a midthoracic "overhemisection." Immediately following the hemisection embryonic (E14) spinal cord transplants were placed into the lesion site. All animals were trained and tested as adults, on a battery of qualitative and quantitative tests of motor function. Immunocytochemical methods were used to compare the extent of growth of descending (serotonergic and noradrenergic) and segmental (calcitonin gene-related peptide containing dorsal root axons) pathways in both groups. The growth of descending pathways into the transplants was substantially greater in density and spatial extent after lesions at birth than at maturity. The distribution of segmental dorsal root axons, in contrast, was similar in both groups. Fetal spinal cord transplants promoted recovery of motor function in both newborn and adult operates. The particular aspects of locomotor function which recover differ between the neonatal and adult operates, suggesting that the mechanisms underlying recovery of function must differ between the two groups.

Finite-element analysis of arterial anastomoses with vein, Dacron and PTFE grafts

A finite-element simulation of an end-to-end artery/graft anastomosis has been presented in this study to evaluate the distribution of compliance and stresses in the vicinity of the anastomosis due to any mismatch in compliance characteristics. The arterial wall was assumed to be made of linear isotropic elastic material in this simplified model and a static analysis was performed with a mean arterial pressure loading of the artery-graft model. Anastomoses to vein grafts and both Dacron and polytetrafluoroethylene (PTFE) grafts were studied. The results suggested the presence of a hypercompliant zone on the arterial side and a region of high tensile stresses in the wall on the graft side of the anastomosis. The presence of a hypercompliant zone has been reported from previous in vivo studies. The hypercompliance was larger with Dacron and PTFE grafts compared with that with the vein graft. However, larger tensile stresses were present in the wall of the vein graft compared with the synthetic grafts. The analysis further showed that increasing the diameter of the graft compared with the host artery to increase flow through the implant will result in a significant increase in the hypercompliance on the arterial side. Such simulation studies may prove valuable in studying the effects of compliance mismatch and suggest ways to improve the design of small diameter vascular grafts.

[Protection on experimental sinus node dysfunction in rabbits with ginsenosides]

This experiment was carried out to evaluate the effect of ginsenosides from stems and leaves (GSL) on the sinus node dysfunction (SND) by observing the changes of the electrophysiological parameters of sinus node in limited period. Anesthetized rabbits were randomly divided into 3 groups. In the acute experiment, GSL, 50 mg/kg, iv, was given to the GSL group (G), n = 12. Normal saline (NS), the same volume, to the control group (C), n = 12. After GSL was administered 30-50 mg/kg.d for 14 days, iv, another data were obtained from chronic experimental group (CE), n = 15. The results show that the parameters, spontaneous cycle length (SCL), maximal sinus node recovery time (SNRTmax), corrected sinus node recovery time (CSNRT) were shorter in G group and CE group than C group respectively (P less than 0.05, P less than 0.01). It was suggested that GSL exerted protective effects on the experimental sinus node dysfunction.