Electronically tuned diode-laser-pumped Cr:LiSrA1F(6) laser

With a liquid-crystal-based birefringent tuner in a coupled resonator, an AlGaInP diode-laser-pumped Cr:LiSrAlF(6) cube laser has been electronically tuned from 858 nm to beyond 920 nm. At an incident pump power of 42 mW, an output power in excess of 4.3 mW was observed near the peak of the tuning curve at 870 nm.

Effects of surface amino acid replacements in cytochrome c peroxidase on complex formation with cytochrome c

Site-directed mutagenesis was employed to examine the role played by specific surface residues in the activity of cytochrome c peroxidase. The double charge, aspartic acid to lysine, point mutations were constructed at positions 37, 79, and 217 on the surface of cytochrome c peroxidase, sites purported to be within or proximal to the recognition site for cytochrome c in an electron-transfer productive complex formed by the two proteins. The resulting mutant peroxidases were examined for catalytic activity by steady-state measurements and binding affinity by two methods, fluorescence binding titration and cytochrome c affinity chromatography. The cloned peroxidases exhibit similar UV-visible spectra to the wild-type yeast protein, indicating that there are no major structural differences between the cloned peroxidases and the wild-type enzyme. The aspartic acid to lysine mutations at positions 79 and 217 exhibited similar turnover numbers and binding affinities to that seen for the "wild type-like" cloned peroxidase. The same change at position 37 caused more than a 10-fold decrease in both turnover of and binding affinity for cytochrome c. This empirical finding localizes a primary recognition region critical to the dynamic complex. Models from the literature proposing structures for the complex between peroxidase and cytochrome c are discussed in light of these findings.

[Determination of paeoniflorin in white peony root and fufang baishao tablets]

Reported in this paper is a method for determining paeoniflorin by TLCS paeoniflorin was separated from the interfering substances by TLC. The average recovery rate was 99.60% and the variation coefficient of the results was 3.67%. This method can be used for grading white peony root and fufang baishao Tablets.

[Assay of stilbene glucoside in Polygonum multiflorum Thunb and its processed products]

This paper reports the assay of stilbene glucoside in the root of Polygonum multiflorum and its two processed products by first derivative spectrophotometry. The method is simple, convenient and the the results are stable and reproducible. It can be used for the quality control of processing Polygonum multiflorum.

[Screening studies on anti-inflammatory function of traditional Chinese herb Gardenia jasminoides Ellis and its possibility in treating soft tissue injuries in animals]

This paper reports the study of six fractions and one chemical constituent isolated from the traditional Chinese herb Gardenia jasminoides. The results showed that two fractions (G5.G6,), alcohol extract (G1) and genipoiside(A) had obvious anti-inflammatory effects and were comparatively effective in treating soft tissue injuries in animals.

[Regulation of atrial natriuretic peptide receptor in cultured aortic vascular smooth muscle cells from stroke-prone spontaneously hypertensive and Wistar-Kyoto rats]

The specific binding sites for atrial natriuretic peptide (ANP) were present in cultured vascular smooth muscle cells (VSMC) from stroke-prone spontaneously hypertensive (SHRsp) and Wistar-Kyoto(WKY) rats with a Bmax of 3.65 +/- 0.13 and 1.89 +/- 0.09 pmol/mg pr. and a Kd of 72.0 +/- 10.2 and 42.1 +/- 4.8 x 10(-12) mol/L, respectively. The basal levels of cGMP of the two strains showed no statistical difference. After treatment with ANP (1.67 x 10(-7) mol/L) for 5 min, the cGMP levels of VSMC were increased by 139 folds in SHRsp and 271 folds in WKY rats, i.e., cGMP levels were significantly lower in the former (P less than 0.01). Therefore, the cultured VSMC of SHRsp had higher ANP receptor density but lower affinity and responsiveness to ANP than that of WKY rats. After incubation of VSMC in the medium containing high NaCl (2-folds of normal) at 37 degrees C for 24 h, the number of ANP binding sites decreased to 34.8 +/- 8.2% in SHRsp and to 38.6 +/- 9.4% in WKY rats (P less than 0.01) with a parallel decrease of cGMP, while the affinity of ANP receptor did not change. It is suggested that the lower responsiveness of ANP receptor to ANP in SHRsp might result in a diminution of vasorelaxation to ANP and thus an increase of arterial pressure. In addition, the more down-regulation of ANP receptor by high NaCl in cultured VSMC from SHRsp implicates that it is one of the mechanisms that high dietary intake of NaCl might enhance high blood pressure.

[Effects of microinjection of clonidine into nucleus tractus solitarii on atrial natriuretic factor in rats]

In order to study whether atrial natriuretic factor (ANF) is involved in the depressor effect of clonidine, microinjection of the latter into nucleus tractus solitarii (NTS) was carried out in anesthetized stroke-prone spontaneously hypertensive rats (SHRsp) and normotensive Wistar-Kyoto (WKY) rats. Each strain was randomly divided into three groups by injecting: (1) clonidine (1.0 microgram/0.2 microliter); (2) yohimbine (3.3 micrograms/0.2 microliter) followed by (1); (3) artificial cerebral spinal fluid (ACSF, 0.2 microliter) as control. A decrease of blood pressure and heart rate and a suppression of ANF release elicited by clonidine were significantly greater in SHRsp than in WKY rats. After blockade of alpha 2-receptor with yohimbine, the hypotensive effect of clonidine was blocked completely in WKY rats, but only partially in SHRsp, while the suppression effect on ANF release was eliminated in both strains. In addition, the decrease of plasma catecholamine produced by clonidine could also be blocked after yohimbine. The results suggest that ANF probably does not contribute to the depressor effect of centrally administered clonidine, while in SHRsp the decrease of plasma ANF might be a blood pressure-dependent compensatory response.

[Determination of cholesterol in natural bezoar by gas chromatography]

A gas chromatographic method for the determination of free and total cholesterol in natural bezoar has been established in this report. The method is simple, specific and accurate. The free and total cholesterol contents in three kinds of bezoar are between 0.072% to 0.214% and 0.546% to 0.608% respectively.

Immunohistochemical localization of bone sialoprotein in foetal porcine bone tissues: comparisons with secreted phosphoprotein 1 (SPP-1, osteopontin) and SPARC (osteonectin)

Bone sialoprotein (BSP) is a prominent component of bone tissues that is expressed by differentiated osteoblastic cells. Affinity-purified antibodies to BSP were prepared and used in combination with biotin-conjugated peroxidase-labeled second antibodies to demonstrate the distribution of this protein in sections of demineralized foetal porcine tibia and calvarial bone. Staining for BSP was observed in the matrix of mineralized bone and also in the mineralized cartilage and associated cells of the epiphysis, but was not observed in the hypertrophic zone nor in any of the soft tissues including the periosteum. In comparison, SPP-1 (osteopontin) and SPARC (osteonectin), which are also major proteins in porcine bone, were observed in the cartilage as well as in the mineralized bone matrix. In addition, SPARC was also present in soft connective tissues. Although SPP-1 distribution was more restricted than SPARC, hypertrophic chondrocytes, periosteal cells and some stromal cells in the bone marrow spaces were stained in addition to osteoblastic cells. The variations in the distribution and cellular expression of BSP, SPARC and SPP-1 in bone and mineralizing cartilage indicate these proteins perform different functions in the formation and remodelling of mineralized connective tissues.

Differential regulation of the 55 and 44 kDa forms of secreted phosphoprotein 1 (SPP-1, osteopontin) in normal and transformed rat bone cells by osteotropic hormones, growth factors and a tumor promoter

Confluent cultures of rat bone cells synthesize several forms of secreted phosphoprotein 1 (SPP-1, osteopontin), the major phosphorylated forms of which migrate at 55 and 44 kDa on 15% cross-linked SDS-PAGE gels and correspond to the transformation-associated proteins pp 69 and pp 62. A clonal rat calvarial cell line (RCA 11), which expressed the highest level of SPP-1, produced only the 55 kDa form of the phosphorylated protein, whereas normal rat calvarial cells enriched in osteoblastic cells (RC IV cells) produced mostly the 55 kDa form, with small amounts of the 44 kDa form. In contrast, a 44 kDa form was the major [32PO4]-labelled SPP-1 synthesized by a rat osteocarcoma cell line (ROS 17/2.8 cells) with lesser amounts of the 55 kDa SPP-1. When [35S]methionine was used to measure protein synthesis, only the 55 kDa SPP-1 could be clearly detected in confluent cultures of each cell population, indicating that the 55 kDa SPP-1 is the prominent form of SPP-1 synthesized by each cell population. Following treatment of the normal rat bone cells for 24 h with osteotropic hormones (vit D3, PTH and RA), growth factors (PDGF, EGF, TGF-beta), a tumor promoter (TPA) and a plant lectin (Con A), the 55 kDa [35S]methionine labelled SPP-1 was increased 1.7-8.3-fold. Similar, but generally lower responses were observed in the clonal RCA 11 cell line, whereas the ROS 17/2.8 cells were more refractory, showing only a strong response to vit D3. In general, vit D3 produced the strongest stimulation in all populations with TGF-beta producing a good response in the non-transformed cells and RA in the RC IV cells. In contrast, PTH was inhibitory in both RCA 11 and ROS 17/2.8 cells. In most, but not all, cases the alteration in SPP-1 synthesis reflected similar changes in SPP-1 mRNA and in the intensity of the [32PO4]-labelled 55 kDa SPP-1. Collectively, these studies demonstrate that bone cells produce several forms of SPP-1 which are differentially regulated in normal and transformed cells through both transcriptional and posttranscriptional mechanisms.

[Determination of trace chloride and sulfate in drugs by ion chromatography]

Chloride and sulfate in magnesium trisilicate, activated charcoal, vesnarinone and bendazac were determined by the IC conductimetric detection. Analysis were performed by using a separating column (100 x 6 mm i.d.) packed with anion exchanger and with a stripper column (100 x 6 mm i.d.); 1.4 mmol/L Na2CO3 and 1.4 mmol/L Na2CO3-0.75 mmol/L NaHCO3 were used as eluents respectively. The peak height was linear with concentration from 10(-6) to 10(-3) mol/L for Cl- and from 10(-5) to 10(-3) mol/L for SO4(2-). Results showed no significant difference as compared with those determined by the CHP (1985) and CHP (1990) appendices methods. The IC method is specific, sensitive, simple and rapid.

Biosynthesis of bone proteins by fetal porcine calvariae in vitro. Rapid association of sulfated sialoproteins (secreted phosphoprotein-1 and bone sialoprotein) and chondroitin sulfate proteoglycan (CS-PGIII) with bone mineral

To study the biosynthesis of bone proteins, fragments of fetal porcine calvariae were cultured in the presence of 50 micrograms/ml ascorbate and 10 mM beta-glycerophosphate and individual cultures labeled for either 4 h or 48 h with [35S]-methionine, Na2[35SO4], Na3[32PO4] or [14C]-glycine plus [14C]-proline. The radiolabeled proteins in tissue extracts were obtained by sequential extraction with 4 M GuHCl (G1-extract), 0.5 M EDTA (E-extract), and again with 4 M GuHCl (G2-extract) and analyzed together with the radiolabeled proteins secreted into the medium. SPP-1 (secreted phosphoprotein 1, osteopontin) was the major non-collagenous protein deposited into the bone matrix, with lesser amounts of BSP (bone sialoprotein), osteocalcin and chondroitin sulfate proteoglycans (CS-PG II and CS-PG III). SPP-1 was also the major phosphorylated protein and was recovered, together with several fragmented forms, almost entirely in the demineralizing extracts. Moreover, approximately one-half of the [35SO4] incorporated into E-extract proteins was present in SPP-1, the remainder being incorporated into PGs with smaller amounts associated with BSP. Over 65% of the [35SO4] in the proteoglycans of the demineralizing extracts was recovered in the small CS-PG III with less than 35% in CS-PG II, the bone homologue of DS-PG II (decorin). In contrast, CS-PG II was the predominant small proteoglycan in culture media and in guanidine extracts. Some sulfated BSP was also observed in guanidine extracts and small amounts appeared to bind to collagen. Radiolabeled SPARC (osteonectin), a prominent protein of fetal porcine bone, was not detected in the mineralized bone tissues but was prominent in the culture medium. These results demonstrate that following secretion, the major proteins expressed by osteoblastic cells are initially incorporated into different tissue compartments, with most of the sulfated sialoproteins and CS-PG III associating rapidly with the hydroxyapatite crystals. The initial distribution of these proteins is of importance in the evaluation of their role in bone formation and mineralization.

[Isolation and characteristics of Borrelia burgdorferi from Ixodes persulcatus]

We reported the detailed characteristics of Lyme disease spirochetes (Borrelia burgdorferi), strain H7, isolated from Ixodes persulcatus in Heilongjiang. Cells of strain H7 were 9.8--26.5 microns long and 0.13--0.35 microns wide. There were 1--11 waves with a wavelength of 1.2--3.0 microns and an amplitude of 0.59--1.13 microns. Direction of spires was left. Seven flagella were inserted subterminally at each end of the cell and ends were pointed. 31 degrees C was the optimum cultural temperature in vitro. The major constitutional and antigenic proteins were 21k, 32k and 34k proteins. H7 could react on the patient sera of Xinjiang and Heilongjiang with IFA and western blot. These findings demonstrated that strain H7 belonged to species Borrelia burgdorferi, but was a new "subtype" which differed from the strains isolated from other areas and vectors.

[Changes in atrial natriuretic peptide and vasopressin during the pressor response to central osmotic stimulation]

In order to study the mechanism of pressor response to central osmotic stimulation, rats were administered with hypertonic artificial cerebrospinal fluid (ACSF) intracerebroventricularly. Carotid arterial pressure and heart rate were recorded. Ten minutes after administration, blood samples, hypothalamus and hypophysis were taken for the determination of atrial natriuretic peptide (ANP) and vasopressin (AVP) by radioimmunoassay. The results showed that after central administration of hypertonic ACSF, the plasma level of AVP increased significantly with no apparent change in ANP. In hypothalamus and hypophysis, the content of ANP was increased while that of AVP decreased.

[Visual pigment genes for color vision defects]

Applying recombinant DNA techniques, the structures of red pigment gene (RPG) and green pigment gene (GPG) were analyzed for 43 patients with protan or deutan (including 3 females), 4 normal relatives and 3 carriers out of 3 families, as well as 11 normal controls. Abnormality of RPG was detected in all 19 protan and that of GPG was found in 14 out of 24 deutan. In about 80% (32/40) of protan and deutan the changing of exon 5 for RPG or GPG was discovered. In protan the normal RPG was replaced by a 5' red -3' green hybrid gene. Some of the deutan had no GPG, some had 5' green -3' red hybrid gene with or without GPG. Furthermore, the exon 5 of RPG and GPG was amplified by polymerase chain reaction (PCR) and further analyzed by Rsa I digestion. The results for PCR are identical to that of Southern blot hybridization.

[Visual pigment genes for color vision defects]

Applying recombinant DNA techniques, the structures of red pigment gene (RPG) and green pigment gene (GPG) were analyzed for 43 patients with protan or deutan (including 3 females), 4 normal relatives and 3 carriers out of 3 families, as well as 11 normal controls. Abnormality of RPG was detected in all 19 protan and that of GPG was found in 14 out of 24 deutan. In about 80% (32/40) of protan and deutan the changing of exon 5 for RPG or GPG was discovered. In protan the normal RPG was replaced by a 5' red -3' green hybrid gene. Some of the deutan had no GPG, some had 5' green -3' red hybrid gene with or without GPG. Furthermore, the exon 5 of RPG and GPG was amplified by polymerase chain reaction (PCR) and further analyzed by Rsa I digestion. The results for PCR are identical to that of Southern blot hybridization.

Genetic and molecular organization of ribosomal DNA (rDNA) variants in wild and cultivated barley

Twenty rDNA spacer-length variants (slvs) have been identified in barley. These slvs form a ladder in which each variant (with one exception) differs from its immediate neighbors by a 115-bp subrepeat. The 20 slvs are organized in two families, one forming an eight-step ladder (slvs 100-107) in the nucleolus organizer region (NOR) of chromosome 7 and the other a 12-step ladder (slvs 108a-118) in the NOR of chromosome 6. The eight shorter slvs (100-107) segregate and serve as markers of eight alleles of Mendelian locus Rrn2 and the 12 longer slvs (108a-118) segregate and serve as markers of 12 alleles of Mendelian locus Rrn1. Most barley plants (90%) are homozygous for two alleles, including one from each the 100-107 and the 108a-118 series. Two types of departures from this typical pattern of molecular and genetic organization were identified, one featuring compound alleles marked by two slvs of Rrn1 or of Rrn2, and the other featuring presence in Rrn1 of alleles normally found in Rrn2, and vice versa. The individual and joint effects on adaptedness of the rDNA alleles are discussed. It was concluded that selection acting on specific genotypes plays a major role in molding the strikingly different allelic and genotypic frequency distributions seen in populations of wild and cultivated barley from different ecogeographical regions.