Study on the relationship between plasma homocysteine and acute cerebral vascular disease

The levels of plasma homocysteine were determined by using high-performance liquid chromatographic method. It was found that plasma homocysteine levels were significantly higher in the patients with stroke than that in the controls. There was no correlation between plasma homocysteine levels and hypertension, smoking, concentrations of blood glucose or hypertriglyceridesemia. It was suggested that hyperhomocysteinemia may be an independent risk factor for acute cerebral vascular disease.

Gas chromatographic--mass spectrometric determination of etomidate in mouse brain

A simple, rapid and reliable method was developed to determine the concentration of etomidate [ethyl-1-(1-phenylethyl)-1 H-imidazole-5-carboxylate] in mouse brain tissue by gas chromatography-mass spectrometry (GC-MS). Ethyl 5-amino-1-phenyl-4-pyrazolecarboxylate was used as internal standard (IS) and liquid-liquid extraction using ethyl ether as the solvent. The method demonstrated excellent recovery (93%) and a linear calibration range of 50-2500 ng/0.2 g. Intra-day accuracy and precision had an error and coefficient of variation of less than 8.7% and 4.2%, respectively. The limit of detection was 1 ng in mouse brain. Our results suggest that this new method is suitable for the quantitative analysis of etomidate in mouse brain tissue.

Methamphetamine administration causes overexpression of nNOS in the mouse striatum

The accumulated evidence suggests that the overproduction of nitric oxide (NO) is involved in methamphetamine (METH)-induced neurotoxicity. Using NADPH-diaphorase histochemistry, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) antibody immunohistochemistry, the possible overexpression of nNOS and iNOS was investigated in the brains of mice treated with METH. The number of positive cells or the density of positive fibers was assessed at 1 h, 24 h and 1 week after METH injections. There were no clear positive iNOS cells and fibers demonstrated in the brains of mice after METH treatment. In contrast, METH caused marked increases in nNOS in the striatum and hippocampus at 1 and 24 h post-treatment. The nNOS expression normalized by 1 week. There were no statistical changes in nNOS expression in the frontal cortex, the cerebellar cortex, nor in the substantia nigra. These results provide further support for the idea that NO is involved in the neurotoxic effects of METH.

Null mutation of c-fos causes exacerbation of methamphetamine-induced neurotoxicity

Methamphetamine neurotoxicity has been demonstrated in rodents and nonhuman primates. These neurotoxic effects may be associated with mechanisms involved in oxidative stress and the activation of immediate early genes (IEG). It is not clear, however, whether these IEG responses are involved in a methamphetamine-induced toxic cascade or in protective mechanisms against the deleterious effects of the drug. As a first step toward clarifying this issue further, the present study was thus undertaken to assess the toxic effects of methamphetamine in heterozygous and homozygous c-fos knock-out as well as wild-type mice. Administration of methamphetamine caused significant reduction in [(125)I]RTI-121-labeled dopamine uptake sites, dopamine transporter protein, and tyrosine hydroxylase-like immunohistochemistry in the striata of wild-type mice. These decreases were significantly exacerbated in heterozygous and homozygous c-fos knock-out mice, with the homozygous showing greater loss of striatal dopaminergic markers. Moreover, in comparison with wild-type animals, both genotypes of c-fos knock-out mice showed more DNA fragmentation, measured by the number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeled nondopaminergic cells in their cortices and striata. In contrast, wild-type mice treated with methamphetamine demonstrated a greater number of glial fibrillary acidic protein-positive cells than did c-fos knock-out mice. These data suggest that c-fos induction in response to toxic doses of methamphetamine might be involved in protective mechanisms against this drug-induced neurotoxicity.

[A study on immunogenicity and safety of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome]

OBJECTIVE

To study side effects and effectiveness of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome in population of a randomized controlled field trial.

METHODS

Serum indirect immunofluorescent antibody in 167 persons and neutralization antibody (types I and II) in 69 persons, who received three-dose vaccine, were determined two weeks after immunization, and side effects in 657 vaccinees were observed within 72 houses after immunization.

RESULTS

Serum positive conversion rate of indirect immunofluorescent antibody was 99.04% (166/167) with GMT of 24.51 +/- 2.06. Serum positive conversion rate of neutralization antibody was 100% (69/69), 91.30% (63/69) for types I and 88.41% (61/69) for type II, respectively. GMTs for type I and II neutralization antibody were 18.27 +/- 2.21 and 12.47 +/- 2.16, respectively. Side effects at local site vaccinated of the body and temperature rising could be seen in 1.48% and 0.36% of the vaccinees, respectively. No severe side effect and abnormal reaction was found in vaccinees on the field.

CONCLUSION

Immune response to bivalent inactivated vaccine against hemorrhagic fever with renal syndrome was satisfactory with slight side effect.

A synthetic peptide derived from human immunodeficiency virus type 1 gp120 downregulates the expression and function of chemokine receptors CCR5 and CXCR4 in monocytes by activating the 7-transmembrane G-protein-coupled receptor FPRL1/LXA4R

Because envelope gp120 of various strains of human immunodeficiency virus type 1 (HIV-1) downregulates the expression and function of a variety of chemoattractant receptors through a process of heterologous desensitization, we investigated whether epitopes derived from gp120 could mimic the effect. A synthetic peptide domain, designated F peptide, corresponding to amino acid residues 414-434 in the V4-C4 region of gp120 of the HIV-1 Bru strain, potently reduced monocyte binding and chemotaxis response to macrophage inflammatory protein 1beta (MIP-1beta) and stromal cell-derived factor 1alpha (SDF-1alpha), chemokines that use the receptors CCR5 and CXCR4, respectively. Further study showed that F peptide by itself is an inducer of chemotaxis and calcium mobilization in human monocytes and neutrophils. In cross-desensitization experiments, among the numerous chemoattractants tested, only the bacterial chemotactic peptide fMLF, when used at high concentrations, partially attenuated calcium mobilization induced by F peptide in phagocytes, suggesting that this peptide domain might share a 7-transmembrane, G-protein-coupled receptor with fMLF. By using cells transfected with cDNAs encoding receptors that interact with fMLF, we found that F peptide uses an fMLF receptor variant, FPRL1, as a functional receptor. The activation of monocytes by F peptide resulted in downregulation of the cell surface expression of CCR5 and CXCR4 in a protein kinase C-dependent manner. These results demonstrate that activation of FPRL1 on human moncytes by a peptide domain derived from HIV-1 gp120 could lead to desensitization of cell response to other chemoattractants. This may explain, at least in part, the initial activation of innate immune responses in HIV-1-infected patients followed by immune suppression.

Microdissection and microcloning of rye (Secale cereale L.) chromosome 1R

Chromosome 1R was microdissected and collected from mitotic metaphase spreads of rye (Secale cereale L.) by using glass needles. The isolated chromosomes were amplified in vitro by Sau3A linker adaptor-mediated polymerase chain reaction (PCR). After amplification, the presence of rye-specific DNA was verified by Southern hybridization. The second-round PCR products from five 1R chromosomes were cloned into a plasmid vector to create a chromosome-specific library, which produced approximately 220,000 recombinant clones. Characterization of the microclone library showed that the 172 clones evaluated ranged in size from 300-1800 bp with an average size of 950 bp, of which approximately 42% were medium/high copy and 58% were low/unique copy clones. Chromosome in situ hybridization confirmed that the PCR products from microdissected chromosomes originated from chromosome 1R, indicating that many chromosome 1R-specific sequences were present in the library.

Ceramide induces Bcl2 dephosphorylation via a mechanism involving mitochondrial PP2A

Phosphorylation of Bcl2 at serine 70 is required for its potent anti-apoptotic function. We have recently shown that Bcl2 phosphorylation is a dynamic process that involves the protein kinase C alpha and protein phosphatase 2A (PP2A) (Ruvolo, P. P., Deng, X., Carr, B. K., and May, W. S. (1998) J. Biol. Chem. 273, 25436-25442; and Deng, X., Ito, T., Carr, B. K., Mumby, M. C., and May, W. S. (1998) J. Biol. Chem. 273, 34157-34163). The potent apoptotic agent ceramide can activate a PP2A, suggesting that one potential component of the ceramide-induced death signal may involve the inactivation of Bcl2. Results indicate that C2-ceramide but not inactive C2-dihydroceramide, was found to specifically activate a mitochondrial PP2A, which rapidly and completely induced Bcl2 dephosphorylation and correlated closely with ceramide-induced cell death. Using a genetic approach, the gain-of-function S70E Bcl2 mutation, which mimics phosphorylation, fails to undergo apoptosis even with the addition of high doses of ceramide (IC50 > 50 microM). In contrast, cells overexpressing exogenous wild-type Bcl2 were sensitive to ceramide at dosages where PP2A is fully active and Bcl2 would be expected to be dephosphorylated (IC50 = 14 microM). These findings indicate that in cells expressing functional Bcl2, the mechanism of death action for ceramide may involve, at least in part, a mitochondrial PP2A that dephosphorylates and inactivates Bcl2.

Treatment with lexipafant ameliorates the severity of pancreatic microvascular endothelial barrier dysfunction in rats with acute hemorrhagic pancreatitis

CONCLUSION

Treatment with lexipafant reduced the severity of pancreatitis-associated endothelial barrier compromise, also associated with a decrease in systemic concentrations of interleukin (IL) 1. Thus, the present findings imply that platelet-activating factor (PAF) may play an important role in the pathogenesis of pancreatic endothelial dysfunction by signaling and triggering the production and release of certain cytokines.

BACKGROUND

Pancreatic capillary endothelial barrier dysfunction is an initial and characteristic feature of acute pancreatic injury and pancreatitis. PAF, a proinflammatory mediator and an intercellular signaling substance, has been considered to be involved in the inflammatory reaction and the systemic endothelial dysfunction of acute pancreatitis.

METHODS

The development of pancreatic capillary endothelial barrier dysfunction was monitored by tissue edema and exudation of plasma albumin into the interstitium, 3 and 12 h after induction of acute pancreatitis by intraductal infusion of 5% sodium taurodeoxycholate in rats. Pancreatic leukocyte recruitment was reflected by measuring myeloperoxidase activity. Serum levels of IL-1 beta and IL-6 were determined by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Pretreatment with lexipafant, a potent PAF receptor antagonist, significantly reduced the pancreatitis-induced increase in pancreatic endothelial barrier dysfunction, pancreatic leukocyte recruitment and serum levels of IL-1 beta, although a difference persisted between animals with sham operation and pancreatitis.

T20/DP178, an ectodomain peptide of human immunodeficiency virus type 1 gp41, is an activator of human phagocyte N-formyl peptide receptor

Human immunodeficiency virus type 1 (HIV-1) envelope protein gp41 mediates viral fusion with human host cells. The peptide segment T20/DP178, located in the C-terminus of the ectodomain of gp41, interacts with the N-terminal leucine zipper-like domain on gp41 to establish the fusogenic conformation of the virus. Synthetic T20/DP178 peptide is highly efficacious in inhibiting HIV-1 infection in vitro by disrupting the transformation of fusogenic status of viral gp41; thus, it has been proposed for clinical trial. We report that synthetic T20/DP178 is a chemoattractant and activator of human peripheral blood phagocytes but not of T lymphocytes. We further demonstrate that T20/DP178 specifically activates a seven-transmembrane, G-protein-coupled phagocyte receptor for N-formylated chemotactic peptides, formyl peptide receptor (FPR). Moreover, synthetic T20/DP178 analogs lacking N-terminal amino acids acted as FPR antagonists. Our results suggest that gp41 peptides regulate phagocyte function via FPR and identify a novel mechanism by which HIV-1 may modulate innate immunity.

Effect of sterilization on the physical and structural characteristics of polyhydroxyoctanoate (PHO)

The present study examined the potential applicability of poly(beta-hydroxy octanoate) (PHO), a bacterial polyester, as a candidate for biomaterial applications, by investigating the effect of sterilization on the physical and structural characteristics of PHO. PHO-cast films were sterilized by either ethylene oxide (EO) gas at 38 degrees C or gamma radiation (2.5 Mrad) in air at room temperature. The physical characteristics of the EO and gamma-sterilized PHO were determined by scanning electron microscopy (SEM) and tensile strength analyses. In addition, various analytical methods were used to detect modifications in the chemical and morphological structure of PHO, namely, electron spectroscopy for chemical analysis (ESCA), Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), and size exclusion chromatography (SEC). The results show that EO sterilization did not modify the chemical and physical characteristics of PHO, however, significant modifications in both the structural and tensile properties were observed with gamma-sterilized PHO. These changes accounted for decreases in both the weight average, number average and melting temperature, and increases in the heat of fusion and tensile strength. No residual EO was detected following sterilization as revealed by head-space chromatography. The physical and structural properties of PHO were shown to be well preserved following EO sterilization, whereas gamma radiation caused random chain scission and physical cross-linking, a frequent phenomenon observed with organic polymers.

Hydrolytic and enzymatic incubation of polyhydroxyoctanoate (PHO): a short-term in vitro study of a degradable bacterial polyester

The present study examined the degradation behaviour of poly(beta-hydroxy octanoate) (PHO), a bacterial poly(beta-hydroxy alkanoate), following incubation under hydrolytic or enzymatic conditions in vitro. Solution-cast PHO films were incubated in a citrate buffer solution with and without acid phosphatase and in an acetate buffer with and without beta-glucuronidase for periods ranging from 7 to 60 days. The physical characterization of the PHO films was analyzed by SEM and tensile strength studies. In addition, various analytical methods were used to detect modifications in the chemical and morphological structure of the PHO, namely, ESCA, FTIR, DSC, X-ray diffraction, and SEC. The results indicate that the enzymatic conditions selected in the present study induced no significant surface morphological or chemical modifications, and no significant weight loss was observed after 60 days of incubation. However, as revealed by weight average molecular weight Mw and number average molecular weight Mn decreases, changes in the bulk structure of the PHO were observed with acid phosphatase at 28 and 60 days, in contrast to smaller Mw and Mn decreases recorded in both the buffers and the beta-glucuronidase. The tensile properties had decreased following incubation, yet showed no difference under all of the selected conditions. With no weight loss or surface changes, the PHO films incubated in acid phosphatase showed only a chemical hydrolytic process characterized by Mw and Mn decreases with time of incubation. The present study demonstrated that the degradation of PHO films is one of slow, chemical hydrolysis only, perhaps requiring several months of incubation. The hydrophobic nature of the long alkyl pendent chain in PHO may be responsible for this slow process. The inability of enzymes to degrade PHO may be attributed to the latter's poor adsorption capacity, due to its hydrophobic nature, and to a lack of specificity in the catalytic activity of these enzymes.

Potential mechanisms responsible for zymosan-associated endothelial injury in rats

OBJECTIVE

To assess alterations in endothelial barrier integrity and potential factors involved in zymosan-associated endothelial injury.

DESIGN

Experimental study.

SETTING

University hospital, Sweden.

ANIMALS

42 adult male Sprague-Dawley rats.

INTERVENTIONS

One hour before an intraperitoneal injection of paraffin or zymosan (0.25 mg/g body weight), 1.0 ml of a solution of saline, N-acetyl-L-cysteine, dimethyl sulphoxide, indomethacin, verapamil, or allopurinol was given intravenously.

MAIN OUTCOME MEASURES

Measurement of tissue water content, tissue intravascular plasma volume, interstitial fluid volume, and extravascular 125I-labelled human serum albumin distribution as well as plasma concentrations of albumin, alpha1-macroglobulin, alpha2-antiplasmin, and antithrombin III, 24 hours after the intraperitoneal injection.

RESULTS

Endothelial permeability significantly increased in abdominal organs and the gastrointestinal tract, and plasma antiplasmin concentrations decreased. Pretreatment with N-acetyl-L-cysteine, dimethyl sulphoxide, or indomethacin protected against zymosan-induced endothelial barrier injury and the decline in protease inhibitors in plasma to varying degrees, while pretreatment with verapamil or allopurinol had a limited effect.

CONCLUSION

Oxygen free radicals, prostaglandin, and proteases may have roles in the pathogenesis of zymosan-induced endothelial barrier injuries, implying that several mediators probably are interacting.

Preliminary study on application of artificial neural network to the diagnosis of Alzheimer's disease with magnetic resonance imaging

OBJECTIVE

Artificial neural network is first used in the measurement study of brain of Alzheimer's disease using MRI, and a completely new pattern discriminating method is adopted, so as to take advantage of MRI to diagnose and identify AD patients.

METHODS

12 patients with probable AD (aged 65.33 +/- 8.62 years) and 36 normal controls matched with age and gender (aged 65.81 +/- 74.37 years) were studied. MRI are performed on Siemens Magnetom IMPACT 1.0 T; eight interesting brain structures including sixteen regions (left and right) indices are measured and studied; SPSS software and BP network software made by authors respectively were used to process and analyze the measured data.

RESULTS

Using artificial neural network to the same regions and data, both the sensitivity and accuracy were found higher than using the traditional discrimination function analysis method; the indices of amygdala, hippocampus, parahippocampal gyrus, temporal lobe, and temporal horn, these five structures could completely differentiate AD from normal controls; new cases were successfully diagnosed.

CONCLUSIONS

Artificial neural network combining with MRI is probable to become a useful and reliable clinical tool to diagnose AD patients.

Investigation on process parameters involved in preparation of poly-DL-lactide-poly(ethylene glycol) microspheres containing Leptospira Interrogans antigens

Block copolymer, poly-DL-lactide-poly(ethylene glycol) (PELA) with 11.5% of poly(ethylene glycol) (PEG) content was prepared by bulk ring-opening polymerization using stannous chloride as initiator. PELA microspheres with entrapped Leptospira Interrogans antigens, outer membrane protein (OMP) were elaborated by solvent extraction method based on the formation of multiple w/o/w emulsion, and the resulting microspheres were characterized with respect to particle size, OMP entrapment and morphology characteristics. The purpose of the present study is to perform the optimization of preparative parameters for OMP-loaded PELA micropsheres to control particle size and improve the OMP encapsulation efficiency. Of all the parameters investigated, the polymer concentration of organic phase and the external aqueous phase volume play major roles on particle size, while the organic phase volume, internal aqueous phase volume and the addition of surfactant into the internal aqueous phase display considerable effects on OMP loading efficiency. A small volume of internal aqueous phase and intermediate volumes of organic phase and external aqueous phase were favorable to achieve micropsheres with a size of 1-2 microns and high antigen encapsulation efficiency (70-80%). In vitro OMP release profiles from PELA microspheres consist of a small burst release followed by a gradual release phase. The OMP release rate shows some relations with the porous and water-swollen inner structure of the microspheres matrix. The presence of surfactant in microspheres accelerates OMP release, but the OMP entrapment within microspheres shows limited effects on the release profile.

[A DNA probe suitable for the detection of chromosome 21 copy number in human interphase nuclei by fluorescence in situ hybridization]

OBJECTIVE

To prepare DNA probe which can be used to accurately detect chromosome 21 copy number in human interphase nuclei by fluorescence in situ hybridization (FISH).

METHODS

A probe was produced by universal primer PCR from YAC clone 881D2 and characterized by FISH to metaphases and interphase nuclei of peripheral lymphocytes from 8 normal individuals and 5 patients suffering from trisomy 21.

RESULTS

A DNA probe was produced and its characteristics were :(1) Most of the probes ranged in size from 350bp to 750bp; (2) The hybridization signals of the probes were located near centromere on long arm of human chromosome 21; (3) In 1524 metaphases scored, about 99.95% of hybridization signals were located on chromosome 21; (4) The signals were very bright and recognizable easily in both metaphases and interphases nuclei; (5) The expected copy number of chromosome 21 was detected by FISH with the probe in more than 98.40% of interphase nuclei and 99.60% of metaphases.

CONCLUSION

The DNA probe reported here is suitable for the detection of chromosome 21 copy number in interphase nuclei and for the study of segregation of chromosome 21 during mitoses of human lymphocytes in culture.

Treatment with lexipafant ameliorates the severity of pancreatic microvascular endothelial barrier dysfunction in rats with acute hemorrhagic pancreatitis

CONCLUSION

Treatment with lexipafant reduced the severity of pancreatitis-associated endothelial barrier compromise, also associated with a decrease in systemic concentrations of interleukin (IL) 1. Thus, the present findings imply that platelet-activating factor (PAF) may play an important role in the pathogenesis of pancreatic endothelial dysfunction by signaling and triggering the production and release of certain cytokines.

BACKGROUND

Pancreatic capillary endothelial barrier dysfunction is an initial and characteristic feature of acute pancreatic injury and pancreatitis. PAF, a proinflammatory mediator and an intercellular signaling substance, has been considered to be involved in the inflammatory reaction and the systemic endothelial dysfunction of acute pancreatitis.

METHODS

The development of pancreatic capillary endothelial barrier dysfunction was monitored by tissue edema and exudation of plasma albumin into the interstitium, 3 and 12 h after induction of acute pancreatitis by intraductal infusion of 5% sodium taurodeoxycholate in rats. Pancreatic leukocyte recruitment was reflected by measuring myeloperoxidase activity. Serum levels of IL-1 beta and IL-6 were determined by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Pretreatment with lexipafant, a potent PAF receptor antagonist, significantly reduced the pancreatitis-induced increase in pancreatic endothelial barrier dysfunction, pancreatic leukocyte recruitment and serum levels of IL-1 beta, although a difference persisted between animals with sham operation and pancreatitis.

[Tissue reaction and degradation of super-high molecular weight poly D, L-lactic acid mini-plates and screws: an animal experiment]

OBJECTIVE

To investigate the tissue reaction and degradation processes of the super-high molecular weight(Mv = 6.0 x 10(5) kD) poly D, L-lactic acid(PDLLA) mini-plates and screws through the internal fixation for zygomatic arch fracture.

METHODS

It was carried out by the self-contrast study method and comparing with the titanium mini-plates and screws.

RESULTS

There was no side-effects on bone healing. The reaction of soft and hard tissues to PDLLA mini-plates and screws was similar to that of the titanium mini-plates and screws. No complication had been seen with the use of PDLLA mini-plates and screws, including infection, foreign body reaction and underlying osteolysis. The PDLLA devices had no changes in shape after 3 months, and then became the grains in different sizes after 6 months, and were completely resorbed within 12 months in vivo.

CONCLUSION

The super-high molecular weight PDLLA mini-plates and screws has good biocompatibility and proper degradation time. It is safe and effective to use the mini-plates and screws made of the super-high molecular weight PDLLA for internal fixation of bone.

[Bone mineral density investigation of normal women in Changsha by dual energy X-ray absorptiometry and its clinical implications]

OBJECTIVE

To establish reference values of bone mineral density (BMD) in normal female.

METHODS

1,257 healthy women aged 15 to 96 years from Changsha were involved. BMD measurements were taken at various skeletal sites (anteroposterior and lateral lumbar spine, hip and forearm) by Hologic QDR4500A dual energy X-ray absorptiometry (DEXA).

RESULTS

(1) The BMD value of Ward's triangle and major trochanter peaked early at the age of 20-24, while that of the one-third mid-distal forearm peaked late at 40-44 years old. (2) Significant loss of BMD (-6.4%, -10.8%) was found at lateral lumbar spine and Ward's triangle respectively before age 45. The acceleration of bone loss at various sites appeared both at age 45-64 and 75 with the maximum magnitude at Ward's triangle (64.4%) and minimum at one-third mid-distal forearm (29.0%-34.3%). (3) The rank of osteoporosis detection rate from high to low after age 40 was lateral lumbar spine (27.8%), forearm, Ward's triangle and anteroposterior lumbar spine (10.5%) and femur neck or major trochanter (10.1%).

CONCLUSION

BMD measurements are necessary in women after age of 40 years. The most sensitive sites for detecting osteoporosis are lateral lumbar spine, Ward's triangle and forearm.

Biochemical maturation of Spam1 (PH-20) during epididymal transit of mouse sperm involves modifications of N-linked oligosaccharides

Indirect immunofluorescence of mouse caput and caudal sperm shows distinctly different distributions of Spaml protein, which is associated with structural and functional differences of the molecule. Spam1 is uniformly distributed over the surface of the head of caput sperm while in caudal sperm, light and confocal microscopy demonstrate that it is localized to the anterior and posterior regions. The hyaluronidase activity of Spaml in acrosome-intact caput sperm was significantly lower (4.3-fold; P < 0.0001) than that of caudal sperm. The increase in enzymatic activity in caudal sperm is accompanied by a reduction in the molecular weight (MW): in extracts from caput sperm there was a major band at approximately 74 kDa and a minor band at approximately 67 kDa; while for the cauda there was a major band at approximately 67 kDa and minor bands at approximately 70 and -56 kDa. Additionally, the bands from caput sperm were 4.9 to 7.7-fold less intense than those from caudal sperm. This decreased affinity for the polyclonal anti-Spaml suggests the presence of different surface characteristics of the molecule from the two epididymal regions. Computer analysis of the protein structure from Spam1 cDNA sequence reveals four putative N-linked glycosylation sites, and enzymatic deglycosylation suggests that all sites are functional. After endoglycosidase activity of extracts from caput and caudal sperm, both show a major band with a MW of approximately 56 kDa, the size of the membrane-anchored polypeptide backbone. Based on the difference in size and intensity of the Spaml bands and hyaluronidase activities from caput and caudal sperm, the data suggest that the activation of Spaml during epididymal maturation is regulated by deglycosylation.

[Morphological and histological studies of Herba Boschniakiae]

This paper deals with the morphological characters of the plants and drugs, and the histological characters of the stems of Herba Boschniakiae (Boschniakia rossica). This results provide authentic methods for the identification of Herba Boschniakiae.

[Internal fixation for zygomatic arch fracture with super-high molecular weight poly D, L-lactic acid mini-plates and screws: a study in dogs]

OBJECTIVE

To investigate the internal fixation effects of super high molecular weight (Mv = 6.0 x 10(5) kD) poly D, L-lactic acid(PDLLA) mini-plates and screws.

METHODS

10 dogs were utilized in this experiment with the self-contrast study method, comparing with the titanium mini-plates and screws.

RESULTS

The mechanical properties of the PDLLA mini-plates and screws appeared to be sufficient to enable undisturbed healing of depressed zygomatic arch fracture.

CONCLUSION

The good fixation effect of PDLLA mini-plates and screws was as same as that of the titanium mini-plates and screws without the need of secondary operation.

[Studies on biosorption of Pb2+ by Phanerochaete chrysosporium]

The biosorption of Pb2+ from solution by Phanerochaete chrysosporium was studied. The effects on biosorption capacity of pH, Pb2+ concentration in solution, co-ion and temperature, time have been examined. The adsorption capacity was compared among the biomass harvested at various growth stages. Pretreatment of biomass by NaOH solution improved its adsorption capacity. The uptake could reach 108.4 mg/g at optimal conditions of biosorption using pretreated biomass.