Expression of type-I collagen and matrix metalloproteinase-9 mRNA in bone of castrated adult female rats: effects of estrogen

OBJECTIVES

To elucidate the molecular changes of bone collagen during the development of postmenopausal osteoporosis and to investigate the molecular effects of estrogen replacement.

METHODS

An adult ovariotomy rat model was used. Type-I collagen and matrix metalloproteinase-9 (MMP-9) expressions in bone tissues of rats treated by sham surgery (SH), bilateral ovariotomy (OVX) and OVX with estradiol (OVX-E2) were analysed at mRNA level by using dot blot technique. The distribution of mRNA of these two genes in bone tissues was studied by in situ hybridization.

RESULTS

The expression levels of both type-I collagen and MMP-9 in bone tissues of OVX rats were higher than those of SH group, while treated with estradiol, the expression of both genes declined to some degree. In situ hybridization showed that type-I collagen mRNA located in osteoblasts, whereas MMP-9 was mainly expressed in osteoclasts, some lining cells on bone surface, and some mononuclear cells in bone marrow.

CONCLUSIONS

The reduction of high bone turnover in osteoporotic bone tissues induced by estrogen replacement may result from alterations in gene expression related to bone formation and bone resorption. These alterations are consistent with the changes observed previously by histomorphometry and biochemical markers of bone metabolism on OVX animals and postmenopausal osteoporosis.

Growth hormone stimulates the tyrosine phosphorylation and association of p125 focal adhesion kinase (FAK) with JAK2. Fak is not required for stat-mediated transcription

We have demonstrated that growth hormone (GH) activates focal adhesion kinase (FAK), and this activation results in the tyrosine phosphorylation of two FAK substrates, paxillin and tensin. The activation of FAK is time-dependent (maximal activation at 5-15 min) and dose-dependent (maximal activation at 0.05 nM). FAK and paxillin are constitutively associated in the unstimulated state, remain associated during the stimulation phase, and recruit tyrosine-phosphorylated tensin to the complex after GH stimulation. Half of the carboxyl-terminal region of the GH receptor is dispensable for FAK activation, but FAK activation does require the proline-rich box 1 region of the GH receptor, indicative that FAK is downstream of JAK2. FAK associates with JAK2 but not JAK1 after GH stimulation of cells. Using FAK-replete and FAK-deficient cells, we also show that FAK is not required for STAT-mediated transcriptional activation by GH. The use of FAK in the signal transduction pathway utilized by GH may be central to many of the pleiotropic effects of GH, including cytoskeletal reorganization, cell migration, chemotaxis, mitogenesis, and/or prevention of apoptosis and gene transcription.

An African HIV-1 sequence from 1959 and implications for the origin of the epidemic

There is considerable genetic diversity among viruses of different subtypes (designated A to J) in the major group of human immunodeficiency virus type 1 (HIV-1), the form of HIV that is dominant in the global epidemic. If available, HIV-1 sequences pre-dating the recognition of AIDS could be crucial in defining the time of origin and the subsequent evolution of these viruses in humans. The oldest known case of HIV-1 infection was reported to be that of a sailor from Manchester who died of an AIDS-like illness in 1959; however, the authenticity of this case has not been confirmed. Genetic analysis of sequences from clinical materials obtained from 1971 to 1976 from members of a Norwegian family infected earlier than 1971 showed that they carried viruses of the HIV-1 outlier group, a variant form that is mainly restricted to West Africa. Here we report the amplification and characterization of viral sequences from a 1959 African plasma sample that was previously found to be HIV-1 seropositive. Multiple phylogenetic analyses not only authenticate this case as the oldest known HIV-1 infection, but also place its viral sequence near the ancestral node of subtypes B and D in the major group, indicating that these HIV-1 subtypes, and perhaps all major-group viruses, may have evolved from a single introduction into the African population not long before 1959.

Clinical study on chronopharmacokinetics of digoxin in patients with congestive heart failure

Fluorescence polarization immunoassay was used to study the chronopharmacokinetics of digoxin in 10 patients with congestive heart failure (CHF) who also served as self-controls. Our results showed that the serum digoxin concentration reached peak value 1 h after taking digoxin at 7:00 a.m., but the serum digoxin concentration reached the peak value 2 h after taking digoxin at 4:00 p.m. The average serum digoxin concentration area under curve was greater and the best maintainable time of serum concentration within 24 h after taking digoxin at 4 p.m. longer than those at 7:00 a.m. The heart rates were obviously lower and the cardiac function was significantly improved in 4:00 p.m. group.

Perception of foreign cigarettes and their advertising in China: a study of college students from 12 universities

OBJECTIVE

To examine how deeply foreign cigarette advertising had penetrated the Chinese market when a new ban on cigarette advertising was enacted in February 1995.

DESIGN

A survey using self-completion questionnaires administered in college classrooms from November 1994 to March 1995.

SETTINGS

Eight universities and four medical schools in three Chinese cities: Beijing, Wenzhou, and Hangzhou.

SUBJECTS

1896 college students who agreed to complete a written questionnaire. The mean age was 21.2 years; 39.5% of respondents were female.

RESULTS

Four of the top eight cigarette brands most familiar to the respondents were foreign: Marlboro, 555, Kent, and Hilton. Advertisements for the foreign brands were much more likely to be seen than those for the domestic brands; those for Marlboro were reported most often (29.7%), followed by 555 (21.8%) and Kent (18.1%). Among smokers, Marlboro was the most preferred foreign brand, by 44.2%. The preference for Marlboro was also correlated with smokers having seen its advertisements. Most respondents, 71.8%, believed that cigarette advertising should be banned.

CONCLUSIONS

The previous restrictions on cigarette advertising in China failed to prevent a large portion of the population from seeing and understanding the advertisements. Before the 1995 advertising ban took effect, strict limitations on imports of foreign cigarettes notwithstanding, certain highly advertised brands such as Marlboro achieved wide recognition and even consumer preference. Stricter restrictions are suggested as previous ones have failed to achieve their intended effects.

Studies on the ossification of compound transplantation of porous TCP ceramics and bone marrow

Following the culture of human red marrow with porous TCP ceramics in vitro, a large amount culturing marrow cells adhered well to the surface and inner wall of TCP ceramics and spread well over the dish bottom 4 weeks after cultivation. After the compound transplantation of porous TCP ceramics with red marrow into quadriceps femoris muscle of rabbits, a huge amount of new bone and marrow formed in these sites on and in the ceramics 4 weeks after transplantation. These results showed an excellent biocompatibility between TCP ceramics and marrow and an excellent osteogenic effect in the compound transplantation. The mechanism of ossification and clinical significance about the compound transplantation were discussed.

The STR120 satellite DNA of soybean: organization, evolution and chromosomal specificity

A highly repeated DNA sequence family, STR120, with tandemly arranged repetitive units (monomers) of approximately 120bp, has been identified in soybean [Glycine max (L.) Merr.]. Five related clones showing tandem repeats of a 120-bp-long monomer were isolated from a soybean genomic library. Results of Southern blotting experiments using three of the clones as probes onto genomic DNA digested with different restriction enzymes were in agreement with a tandem arrangement of these sequences in the genome. A total of 12 monomers were sequenced, showing considerable sequence heterogeneity. A consensus sequence of 126 bp was obtained that exhibits an average similarity of 81% to the sequenced units. In three of the clones identified, neighbouring units are significantly more similar to each other than to units from different clones; in the remaining two clones, however, similarity between the two units observed is low (70%), while the overall similarity between the two clones is high (95%). This indicates that in these cases the repetitive unit may be the dimer rather than the monomer. Based on the presence of direct repeats within each monomer, we suggest that the 120-bp monomer may itself have evolved by duplication of an ancestral 60-bp unit. The STR120 family distribution is limited to annual soybeans and is not found, at least at high-copy number, in related perennial soybeans or other members of the tribe Phaseolae. Fluorescence in situ hybridization (FISH) to metaphase chromosomes using four of the clones as probes shows that the number of chromosomal locations differs depending on the stringency conditions and goes from two to eight when the stringency is progressively lowered. The estimated copy number for one of the clones is from 5000 to 10000, but this may just represent a lower boundary for the whole family in consideration of the high sequence divergence observed within the family. FISH and sequence analysis therefore indicate that different subfamilies as well as higher-order repeat units are present in the STR120 family, very much like those in primate alpha satellite DNA, and that some of the subfamilies seem to exhibit divergence on a chromosomal basis.

[Colour Doppler ultrasonographic indices in predicting fetal hypoxia and acidosis]

OBJECTIVE

To evaluate the effect of uterine-placental-fetal blood flow velocity waveforms (FVWs) on predicting fetal hypoxia and acidosis in high risk pregnancy.

METHODS

46 women of normal term pregnancy (normal group) and 32 women of high risk term pregnancy (high risk group) were examined with colour Doppler ultrasound for their FVWs including maternal uterine artery (UtA), fetal umbilical artery (UmA), middle cerebral artery (MCA), and renal artery (RA). Umbilical artery blood gases were analysed at delivery in high risk group.

RESULTS

The resistance index (RI), pulsatile index (PI) and ratio of peak systolic to least diastolic flow velocity (S/D) of UtA, UmA and RA were higher and the PI, S/D of MCA was lower significantly in the high risk group than that of normal the group (P < 0.05). In the high risk pregnancy, when UmA PO2 was less than 2.5 kPa, the S/D of UtA, PI, S/D of UmA and RI, PI, S/D of RA were increased, and the PI of MCA was decreased (P < 0.05). There were a positive correlation between PI of UmA, RA and PO2 pH of UmA, and a negative correlation between the former and PCO2 of UmA. But there were a negative correlation between PI of MCA and PO2, pH of UmA, and a positive correlation between the former and UmA PCO2.

CONCLUSION

In the high risk pregnancy, fetal cerebral blood flow increased, whereas blood flow of fetal peripheral vessels (especially renal vessel) decreases. There is a good correlation between fetal hypoxia and fetal blood FVWs. The indices of the fetal blood FVMs can identify fetal hypoxia and acidosis.

[Research on omni-directional ultrasonic imaging]

In this paper, an omni-direction M-mode ultrasonic imaging method is introduced, in which M-mode sample line can rotate and move freely. In this way the measurement of parameters such as amplitude and speed of movement of organs can be conducted in any position or direction. We analyzed the sources of errors of the method and the way to overcome them.

The interconversion of protein phosphatase 2A between PP2A1 and PP2A0 during retinoic acid-induced granulocytic differentiation and a modification on the catalytic subunit in S phase of HL-60 cells

Alterations in protein phosphatase 2A (PP2A) during retinoic acid-induced differentiation of HL-60 cells have been investigated. PP2A activity of HL-60 cells for phosphorylated myelin basic protein showed a sharp and transient increase after 18-h treatment with 1 microM retinoic acid, which corresponded to G1/S boundary of the cell cycle. This PP2A of the 18-h treated cells was eluted from a DEAE-Sepharose column with 0.13 M NaCl, while PP2A from control cells was eluted with 0.23 M NaCl. The phosphorylase phosphatase activity of PP2A in the 0.13 M eluate was greatly enhanced in the presence of protamine compared with that of the later eluting PP2A. Immunoblot analyses with antisera against B' and B alpha subunits showed that the PP2A in the 0.13 M NaCl eluate from 18-h retinoic acid-treated cells was PP2A0 (AC-B'), whereas the PP2A eluted with 0.23 M NaCl from 24-h retinoic acid-treated cells and 0-, 18-, and 24-h control cells was PP2A1 (AC-B alpha). These results strongly suggest that PP2A undergoes a transient and reversible interconversion of holoenzyme forms during the initial stage of retinoic acid-induced granulocytic differentiation. PP2A activity assayed after dissociation of the catalytic subunit, for phosphorylase as substrate, showed a sharp and transient decrease in S phase of HL-60 cells irrespective of the presence or absence of retinoic acid. Immunoblot analyses with antisera against C-terminus and N-terminus of the catalytic subunit of PP2A suggested that a modification at the C-terminus is responsible for the decrease in PP2A activity. Immunoreactivity to the C-terminal antibody was restored after treatments of the S-phase extract with alkali or ethanol, the conditions which remove the methyl group from the C-terminus. These results suggest that the C-terminus of PP2A catalytic subunit is transiently methylated in S phase of HL-60 cells.

Tissue response and the cytoconduction ability to collagen/hydroxyapatite heterotopic implantation

A histological and ultrastructural observation of CHA implanted intramuscularly and subcutaneously had been reported. Our results showed that a mild inflammation developed at the early stage and disappeared 2 weeks after implantation. The infiltrating cells were mainly monocyte-macrophages, a number of fibroblasts followed macrophages closely. It was possible that as CHA degrades, monocyte-macrophages continuously released inflammatory factors, thus enhancing fibroblast proliferation activity and tissue regeneration. In addition, the heterotopic calcification of collagen matrix was observed, suggesting that CHA promoted calcification deposition.

[The study of the morphology of ultramicrostructure in molecular level of nucleus herniation of lumbar intervertebral disc]

In order to investigate the morphology of ultramicrostructure in molecular level of nucleus herniations, the authors studied the ultramicrostructure of three cases of nucleus herniations of lumbar intervertebral disc which were proved by operations and one case of normal nucleus pulposus of fresh corpse by using of atomic force microscope. The results showed that the arrangement of collagen bundle, collagen fiber and procollagen fiber were different between the two conditions, and the morphology of molecular particles of proteoglycan in nucleus herniations was different from that in the normal condition. In the condition of nucleus herniations, the collagen fiber formed procollagen fiber reticular porous adhering to the molecules of protein and proteoglycan, and the DNA adhering to the monochain of RNA in fiberal cell nuclei, in the form of bichain and multichain three dimensions helix structures. The banded structure (64-78 mm) of the procollagen fiber, and the collagenation and calcification of the degenerated nuclens pulposuses, the quantity of which was significant greater than normal (P < 0.05) indicated that the chronic injury of lumbar intervertebral nucleus pulposuses gave rise to the injury and break of the collagen fiber which resulted in twist (tangle) phenomenon so that nucleus pulposuses lost their normal resistance strength.

Characterization and application of soybean YACs to molecular cytogenetics

Yeast artificial chromosomes (YACs) are widely used in the physical analysis of complex genomes. In addition to their value in chromosome walking for map-based cloning, YACs represent excellent probes for chromosome mapping using fluorescence in situ hybridization (FISH). We have screened such a library for low-copy-number clones by hybridization to total genomic DNA. Four clones were chosen for chromosome tagging based upon their low or moderate signal. By using degenerate oligonucleotide-primed PCR (DOP-PCR), we were able to use relatively small amounts of soybean YAC DNA, isolated directly by preparative pulsed-field gel electrophoresis, as FISH probes for both metaphase chromosome spreads and interphase nuclei. FISH chromosomal analysis using the three of the clones as probes resulted in relatively simple hybridization patterns consistent with a single homologous locus or two homoeologous loci. The fourth YAC probe resulted in a diffuse hybridization pattern with signal on all metaphase chromosomes. We conclude that YACs represent a valuable source of probes for chromosomal analysis in soybean.

Soybean chromosome painting: a strategy for somatic cytogenetics

Cytological identification of soybean mitotic metaphase chromosomes (2n = 40) has been severely limited by their small size and uniform karyomorphology. We have developed fluorescent in situ hybridization (FISH), PCR-primed in situ labelling (PCR-PRINS) procedures, and molecular probes for routine cytological identification and for the physical mapping of soybean somatic chromosomes. Chromosome preparation has been achieved by modifications of previous protocols and through the preparation of root-tip protoplasts prior to chromosome spreading. Initially our probe selection focused on highly repeated DNAs that provide very intense localized hybridization signals. Repetitive gene probes that have proven valuable include the rDNA loci (5S and 45S) which are chromosome specific. We have also developed satellite DNA probes for two different sequence families: the SB92 and the STR120 satellites. Both of these are tandemly arranged at multiple chromosomal loci. By using different cloned examples of each family, we have been able to selectively label unique subsets of soybean chromosomes. Double hybridization with biotin and digoxigenin labeled probes has allowed us to determine the chromosomal overlap between different probes. In addition, we have joined portions of the metaphase chromosome painting patterns with the genetic map by single-copy FISH and PCR-PRINS detection of the RFLP loci G8.15, G17.3, and A199a and A199b. Total genomic DNA in situ hybridization (GISH) patterns were also used to characterize the soybean chromosomes.

Ribosomal RNA genes in soybean and common bean: chromosomal organization, expression, and evolution

Ribosomal RNA (5S and 45S) genes were investigated by FISH in two related legumes: soybean [Glycine max (L.) Merr.] and common bean (Phaseolis vulgaris L.). These species are both members of the same tribe (Phaseoleae), but common bean is diploid while soybean is a tetraploid which has undergone diploidization. In contrast to ploidy expectations, soybean had only one 5S and one 45S rDNA locus whereas common bean had more than two 5S rDNA loci and two 45S rDNA loci. Double hybridization experiments with differentially labelled probes indicated that the soybean 45S and 5S rDNA loci are located on different chromosomes and in their distal regions. Likewise, the common bean 45S and 5S rDNA loci were on unique chromosomes, though two of the 5S rDNA loci were on the same chromosome. FISH analysis of interphase nuclei revealed the spatial arrangement of rDNA loci and suggested expression patterns. In both species, we observed one or more 5S rDNA hybridization sites and two 45S rDNA hybridization sites associated with the nucleolar periphery. The 45S rDNA hybridization patterns frequently exhibited gene puffs as de-condensed chromatin strings within the nucleoli. The other condensed rDNA sites (both 5S and 45S) were spatially distant from the nucleolus in nucleoplasmic regions containing heterochromatin. The distribution of rDNA between the nucleoplasm and the nucleoli is consistent with differential gene expression between homologous alleles and among homoeologous loci.

Genetic characterization of human immunodeficiency virus type 1 in blood and genital secretions: evidence for viral compartmentalization and selection during sexual transmission

To explore the mechanism of sexual transmission of human immunodeficiency virus type 1 (HIV-1), we compared HIV-1 gp120 sequences in longitudinal samples from five acute seroconvertors with those from their corresponding sexual partners (transmitters). We used a quantitative homoduplex tracking assay to compare the overall genetic composition of HIV-1 quasispecies in each transmission pair and to track the transmitted viruses during the acute and asymptomatic stages of HIV-1 infection. In the chronically infected transmitters, HIV-1 variants in genital secretions differed from those in blood and variants in cells differed from those in cell-free plasma, indicating remarkable sequence heterogeneity in these subjects as well as compartmentalization of the virus in different bodily sites. Conversely, two of five seroconvertors had only a few related variants and three of five harbored only one viral population, indicating that in these subjects the transmitted viruses were typically homogeneous. Transmitted viruses were evident in the donor's seminal plasma (one of five cases) and even more so in their seminal cells (three of five cases), suggesting that both cell-associated and cell-free viruses can be transmitted. In every pair studied, the transmitted variant(s) represents only a minor population in the semen of the corresponding transmitter, thereby providing evidence that HIV-1 selection indeed occurs during sexual transmission.

Sperm Identification in Maize by Fluorescence in Situ Hybridization

The two sperm cells of common origin within the pollen tube of flowering plants are each involved in a fertilization event. It has long been recognized that preferential fusion of one sperm with the egg can occur in B chromosome-containing lines of maize. If the second pollen mitosis begins with a single B chromosome, nondisjunction will result in one sperm possessing two B chromosomes and the other containing no B chromosomes. The B chromosome-containing sperm most often fertilizes the egg, whereas the sperm nucleus with no B chromosomes fuses with the polar nuclei. Despite the obvious advantages of being able to recognize and then track, separate, and analyze one sperm type from the other, it has not been possible because of the lack of sufficient detectable differences between the two types of sperms. In this study, we used a B chromosome-specific DNA sequence (pZmBs) and in situ hybridization to identify and track the B chromosome-containing sperm cell within mature pollen and pollen tubes. Our results are consistent with conclusions from previous genetic studies related to B chromosome behavior during pollen formation. Within pollen tubes, the position in which the B chromosome-containing sperm travels (leading or trailing) in relation to the sperm cell lacking B chromosomes appears to be random.

[Alterations of protein phosphatases, PP2A and PP1, during retinoic acid-induced differentiation of HL-60 cells]

Alterations of protein phosphatases, PP2A and PP1, during the retinoic acid-induced differentiation of HL-60 cells have been investigated. The PP2A activity determined with myelin basic protein (MBP) as a substrate showed a sharp transient increase at 18 h of incubation of the cells with retinoic acid, whereas during incubation without retinoic acid, the activity remained at the initial level. On DEAE-Sepharose column chromatography of the extracts preparted from the cells incubated without retinoic acid, the PP2A activities determined with MBP were eluted at 0.13 M or 0.23 m NaCl, respectively. The PP2A activity of the cells incubated for 18 h with retinoic acid was much more greatly activated by protamine compared with the activity of the cells incubated without retinoic acid. These results strongly suggest a conversion of PP2A holoenzyme from PP2A1 to PP2A0 during the initial process of the retinoic acid-induced differentiation. On the other hand PP2A activity determined with phosphorylase alpha as a substrate showed a sharp transient decrease at 24 h of incubation of the cells, irrespective of the presence or the absence of retinoic acid in the incubation mixtures. This decrease may be related to the synchronization of the cells at S phase, which also occurred irrespective of the retinoic acid stimulation. PP1 activity determined with MBP was transiently increased between 27 and 36 h of the incubation of cells without retinoic acid. The increase was strongly suppressed in the cells incubated with retinoic acid, suggesting a role of PP1 in the cell proliferation, the activity of which was also inhibited by retinoic acid.

Epiphyseal lengthening operation--an improved technique

An improved method of epiphyseal lengthening operation and subsequent outer fixation are presented on the basis of experience in 30 cases. The operative technique is described in detail, including the different options of separative traction and osteotomy at subtrochanteric, distal part of the upper femur and lower tibial levels. The physiological and histological research concerning this method is discussed. The authors believe that this procedure is better than the other methods.

Hybridization properties of oligodeoxynucleotide pairs bridged by polyarginine peptides

The hybridization properties of a series of probes, based on two 9mer oligodeoxynucleotides (designated as I and II) having an appended oligoarginine chain (Rn) to produce peptide-oligonucleotide conjugates or peptide-bridged oligonucleotide pairs (e.g. Rn-I or II-Rn-I), were investigated. For the double-linked probes, we found that the peptide bridge induces the two 9mers to bind complementary single-stranded DNA or RNA targets with substantially enhanced thermal stability. The resulting hybrid with complementary DNA was found to assume a 1:1 complex in the B conformation as judged by UV mixing curves and CD spectroscopy. Complexes of single or double-linked probes with complementary RNA exhibited sensitivity to RNase H digestion. The influence of the identity and chirality of the repeating unit in the bridge, the length of the bridge, the gap size and the salt concentration on the hybridization properties of this new class of oligonucleotide probes was also studied. Our data reveal that these compounds exhibit properties that should prove useful in the development of antisense strategies.

Functional expression of mammalian myosin I beta: analysis of its motor activity

The motor function of vertebrate unconventional myosins is not well understood. In this study, we initiated the baculovirus expression system to characterize a novel myosin I from bovine adrenal gland that we had previously cloned [Zhu, T., & Ikebe, M. (1994) FEBS Lett. 339, 31-36], which is classified as myosin I beta. The expressed myosin I beta was well extracted when calmodulin was coexpressed in Sf9 cells. The recombinant myosin I beta cosedimented with actin in an ATP dependent manner. The purified myosin I beta was composed of one heavy chain and three calmodulins. The electron microscopic image of myosin I beta confirmed its single-headed structure with a short tail, which is similar to that of brush border myosin I (BBMI). Myosin I beta showed high K+,EDTA--ATPase activity (approximately 0.14 mumol/min/mg) and Ca(2+)-ATPase activity (approximately 0.32 mumol/min/mg), and the KCl/pH dependence of these activities was different from that of conventional myosin. Mg(2+)-ATPase activity of myosin I beta alone was increased above pCa 6, while the actin dependent activity was not affected by Ca2+. Actin sliding velocity of myosin I beta in the absence of Ca2+ was 0.3-0.5 microns/s at 25 degrees C, which is much greater than that of BBMI (< 0.05 microns/s). The actin sliding activity was abolished above pCa 6, and the sliding activity was restored when exogenous calmodulin was added in the absence of Ca2+. Within similar Ca2+ concentrations, one of the three calmodulins was dissociated from myosin I beta. The results suggest that Ca2+ dependent association of calmodulin may function as a regulatory mechanism of myosin I beta motor activity and that the motor activity of mammalian myosin I is largely different among distinct myosin I isoforms.

[The cloning and analysis of a single gene in Drosophila homologic with human oncogene TTG]

The human TTG/RBTN family is an oncogene family. There are three members in this family: TTG-1/RBTN-1, TTG-2/RBTN-2 and TTG-3/RBTN-3. Two of them, TTG-1/RBTN-1 and TTG-2/RBTN-2 have been isolated at the sites of chromosomal translocations in T-cell leukaemia. This gene family encodes cysteine-rich proteins with two tandem copies of a LIM motif. The function of the LIM motif is unknown. We found that the TTG-2 gene is highly conserved among mammals; Drosophila and yeast. As a first step to obtain a model system for studying the function of the LIM motifs, we isolated the Drosophila homologue dttg. In contrast to human, Drosophila appeared to have only one ttg/rbtn gene. A 2087bp cDNA clone was isolated, encoding a protein of 266 amino acids. A second transcript with an alternative 5' end was identified in RNA from embryos. The Drosophila ttg protein consisted of two tandem copies of the conserved LIM domain characteristic of the human TTG/RBTN family. The amino acid sequence similarity with human TTG-1 and TTG-2 is 79% and 62%, respectively. The dttg, like TTG-1, have an intron in the second LIM encoding region, which is not present in TTG-2.

Gel shift assay: demonstration of enhanced binding of oligo(delta)-L-ornithine-oligodeoxynucleotide conjugates to complementary DNA and RNA

An increase in melting temperature for DNA:DNA duplexes had been observed previously (Zhu et al. Antisense Res. Dev. 3:349-356, 1993) when an oligo(delta)ornithine moiety was covalently appended to a short oligodeoxynucleotide. We now report the analysis of duplex formation by electrophoretic gel shift analysis. In the particular example studied, an increase in Tm of 4 degrees C was found to correspond to about a fivefold increase in binding constant. A similar enhancement by the appended cationic peptide was observed when the target strand was RNA. The use of a competitive assay format for avoidance of adsorptive loss at low concentrations (< 10(-7)M) of the oligonucleotide-oligo(delta)ornithine conjugate is presented.

Genomic organization and evolution of the soybean SB92 satellite sequence

Repetitive DNA sequences comprise a large percentage of plant genomes, and their characterization provides information about both species and genome evolution. We have isolated a recombinant clone containing a highly repeated DNA element (SB92) that is homologous to ca. 0.9% of the soybean genome or about 10(5) copies. This repeated sequence is tandemly arranged and is found in four or five major genomic locations. FISH analysis of metaphase chromosomes suggests that two of these locations are centromeric. We have determined the sequence of two cloned repeats and performed genomic sequencing to obtain a consensus sequence. The consensus repeat size was 92 bp and exhibited an average of 10% nucleotide substitution relative to the two cloned repeats. This high level of sequence diversity suggests an ancient origin but is inconsistent with the limited phylogenetic distribution of SB92, which is found at high copy number only in the annual soybeans. It therefore seems likely that this sequence is undergoing very rapid evolution.

A single nuclear locus phylogeny of soybean based on DNA sequence

Soybean [Glycine max (L.) Merr.] evolution was examined by sequencing portions of the restriction fragment length polymorphism (RFLP) locus A-199a of 21 taxa from the Glycininae and 1 from the Phaseoleae. Four hundred nucleotides were determined in each, aligned, and then compared for these taxa. Within the annual soybean subgenus (Soja), the four accessions differed at as many as 2.2% of the nucleotides. Among 13 perennial soybean species (subgenus Glycine), nucleotide variation ranged from 1.7% to 8.4%. The nucleotide difference between the two soybean subgenera was 3.0-7.0%. Nucleotide variation between the genus Glycine and the related genera of Neonotonia, Amphicarpa, Teramnus, and Phaseolus ranged from 8.2% to 16.4%. In addition to nucleotide substitutions, insertions/deletions (indels) differences were also observed and were consistent with nucleotide-based analysis. Cladistic analysis of the A-199a sequences was performed using Wagner parsimony to construct a soybean phylogeny. Sixteen equally parsimonious trees were produced from these data. The trees were 246 steps in length with a consistency index of 0.78. Indels distribution upon the consensus topology revealed a pattern congruent with the nucleotide-based phylogeny. The current taxonomic status of the soybean subgenera and the related genera of Neonotonia, Amphicarpa, and Teramnus were well-supported and appear monophyletic in this analysis. Homoplasy within the subgenus Glycine led to a lack of resolved topology for many of these 13 taxa. However, the Glycine clade topology was consistent with phylogenies proposed using crossing experiments and cpDNA RFLPs. These genera were arranged from ancestral to derived as: Teramnus, Amphicarpa, Neonotonia, and Glycine when Phaseolus vulgaris was used as an outgroup.

[Analysis of poisonous trace elements in huangwu gongmitai]

A comparative study was made on the dissolved amount of poisonous trace elements mercury and arsenic contained in hydrargyri subchloridum and realgar of gynecological suppository in artificially simulated vaginal acid-base liquid with that contained in hydrargyri subchloridum and realgar in artificial gastric juice stipulated in Pharmacopeia of China. The result shows that the dissolved amount of mercury and arsenic contained in the suppository is much smaller than that stipulated in Pharmacopeia for oral administration.

Doses near the surface in high-energy x-ray beams

In an irradiation with a high-energy x-ray beam, the absorbed dose near the surface is the combined result of incident contaminating electrons and phantom-generated electrons. We describe an experimental method to characterize these processes under conditions of longitudinal electron disequilibrium but lateral equilibrium. The equilibrium dose at large depths is extrapolated back towards the surface and compared with measured doses. The extrapolation uses an expression that is based on Monte Carlo-calculated kerma values. The technique was applied to a 6-MV and a 25-MV x-ray beam. The dose from phantom-generated electrons increased exponentially with depth from zero at the surface. The dose from contaminating electrons decreased rapidly with depth with an attenuation coefficient that was approximately equal to the corresponding coefficient for the increase of dose from phantom-generated electrons. The surface dose from contaminating electrons increased linearly with the side of the square field at 6 MV but an error-function agreed better with the data at 25 MV.

Sequence diversity of V1 and V2 domains of gp120 from human immunodeficiency virus type 1: lack of correlation with viral phenotype

We analyzed by PCR and direct sequencing 57 viral sequences from 47 individuals infected with human immunodeficiency virus type 1, focussing on the V1 and V2 regions of gp120. There was extensive length polymorphism in the V1 region, which rendered sequence alignment difficult. The V2 hypervariable locus also displayed considerable length variations, whereas flanking regions were relatively conserved. Two-thirds of the amino acid residues in these flanking regions were highly conserved (> 80%), presumably reflecting their critical contribution to V2 structure or function. We also characterized the syncytium-inducing properties of the isolates from which we derived sequence information. There was no correlation between V1 or V2 sequences and the viral phenotype, contrary to a previous report (M. Groenink, R. A. M. Fouchier, S. Broersen, C. H. Baker, M. Koot, A. B. van't Wout, H. G. Huisman, F. Miedema, M. Tersmette, and H. Schuitemaker, Science 260:1513-1516, 1993). The sequence heterogeneity described in this study provides information to suggest that it would be most difficult to exploit the V1 and V2 domains for vaccine development.

[Promoting effects of rhizoma Drynariae on the calcification of cultivated chick embryo bone primordium]

It has been discovered by tissue cultivation and isotope tracing that the injection of Rhizoma Drynariae significantly promotes the calcification of chick embryo bone primordium in vitro, increases the ALP activity of cultivated tissues and accelerates the synthesis of proteoglycan. It has also been proved that the promotion of the synthesis of proteoglycan is an important factor of the promotion of calcification.

Evidence for coinfection by multiple strains of human immunodeficiency virus type 1 subtype B in an acute seroconvertor

Sequences encoding the envelope glycoprotein of human immunodeficiency virus type 1 (HIV-1) were amplified by PCR from plasma and peripheral blood mononuclear cells obtained at four time points from an acute seroconvertor. Genetic analyses, including nucleotide sequencing and heteroduplex mobility studies, showed that the patient harbored three distinct populations of HIV-1 clade B envelope sequences, with nucleotide distances ranging from 9.2 to 17.2%. One population of sequences was clearly distinguishable from the others on the basis of phylogenetic analysis. In addition, sequences suggesting recombination between two of the three distinct viral populations were also found. This case of acute seroconversion provides clear and conclusive evidence that coinfection by multiple HIV-1 strains can indeed occur in vivo.

Hypomethylated sequences: characterization of the duplicate soybean genome

Soybean is believed to be a diploidized tetraploid generated from an allotetraploid ancestor. In this study, we used hypomethylated genomic DNA as a source of probes to investigate the genomic structure and methylation patterns of duplicated sequences. Forty-five genomic clones from Phaseolus vulgaris and 664 genomic clones from Glycine max were used to examine the duplicated regions in the soybean genome. Southern analysis of genomic DNA using probes from both sources revealed that greater than 15% of the hypomethylated genomic regions were only present once in the soybean genome. The remaining ca. 85% of the hypomethylated regions comprise duplicated or middle repetitive DNA sequences. If only the ratio of single to duplicate probe patterns is considered, it appears that 25% of the single-copy sequences have been lost. By using a subset of probes that only detected duplicated sequences, we examined the methylation status of the homeologous genomes with the restriction enzymes MspI and HpaII. We found that in all cases both copies of these regions were hypomethylated, although there were examples of low-level methylation. It appears that duplicate sequences are being eliminated in the diploidization process. Our data reveal no evidence that duplicated sequences are being "silenced" by inactivation correlated with methylation patterns.

Synthesis of oligoarginine-oligonucleotide conjugates and oligoarginine-bridged oligonucleotide pairs

Conjugates consisting of oligoarginine peptides linked to oligodeoxynucleotides have been synthesized, including a new type of conjugate, in which a pair of oligonucleotides is bridged by a cationic peptide. Two different 9-mer oligonucleotides were conjugated to the terminal cysteine residues of the peptide series H-Cys-(Arg)n-Cys-NH2 (n = 3, 5, 7). Different thiol protecting groups were utilized on the amino- and carboxy-terminal cysteine residues of the peptide to allow selective attachment to the 3'- or 5'-terminus of each specific oligonucleotide. The conjugates containing oligoarginine peptides were purified by anion-exchange chromatography, and their structures were confirmed by polyacrylamide gel electrophoresis and amino acid analysis.

Purity control of different bee venom melittin preparations by capillary zone electrophoresis

A rapid capillary zone electrophoresis method was developed for the determination of melittin during its purification from bee venom by column chromatography. Low-pH buffer was selected to decrease the adsorption of the analytes on capillary wall. The average relative standard deviations of the migration time of melittin and of the peak area were 1.2 and 2.3%, respectively.

Preparation of vitamin B6-conjugated peptides at the amino terminus and of vitamin B6-peptide-oligonucleotide conjugates

A series of N-(4'-pyridoxyl)peptides has been made by standard Fmoc chemistry and a solid-phase coupling procedure. The last Fmoc group of the peptide was removed on the synthesizer, and the free amino group was then condensed with pyridoxal. The Schiff base formed was selectively reduced using sodium cyanoborohydride. The product was cleaved from the resin using a standard procedure. No deleterious effects were found when using the protected amino acids Fmoc-L-Ala, Fmoc-L-Arg(Pmc), Fmoc-L-Asp(OtBu), Fmoc-L-His(Trt), Fmoc-L-Ser(tBu), Fmoc-L-Thr(tBu), and Fmoc-L-Cys(Trt) for peptide synthesis. A vitamin B6-peptide-oligonucleotide conjugate could be synthesized using a cysteinyl peptide and a suitably activated oligonucleotide.

A novel myosin I from bovine adrenal gland

A 3.5 kb cDNA clone was isolated from bovine adrenal gland cDNA library. The clone contained a full-length 3.1 kb open reading frame, encoding a novel myosin I. The deduced amino acid sequence was highly homologous to other known myosin Is in the N-terminal 2 kb region which corresponds to the myosin head domain, while no strong homology was detected in the tail region. The head-tail junction contained the Ca(2+)-independent calmodulin binding consensus sequence, suggesting that the novel myosin I binds calmodulin. This was confirmed by calmodulin overlay which showed the binding of 125I-calmodulin to the recombinant myosin I expressed in E. coli. Northern blots with probes from head and tail regions of this myosin I revealed that this novel myosin I is widely distributed among various tissues.

Characterization of human immunodeficiency virus type 1-specific cytotoxic T lymphocyte clones isolated during acute seroconversion: recognition of autologous virus sequences within a conserved immunodominant epitope

Virus-specific cytotoxic T lymphocytes (CTL) are involved in protective immunity to many virus infections. It has recently been shown that CTL are detectable early during primary infection with the primate lentiviruses, human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus. To better characterize the CTL response during acute HIV-1 infection, HIV-1-specific CTL clones were generated from two patients during symptomatic HIV-1 seroconversion. These CTL clones demonstrated specificity for env of HIV-1 and recognized sequences within gp41. Two human histocompatibility leukocyte antigen (HLA) A31-restricted clones from the same individual were found to have differing virus strain specificities. Both clones recognized the 11-amino acid peptide RLRDLLLIVTR from position 770-780 of gp41. A change from T to V at position 779 in this epitope abrogated lysis by one clone but not the other. A CTL clone from the other patient, restricted by a different class I HLA allele, recognized the nine-amino acid peptide HRLRDLLLI from position 769-777 of gp41. Of note, the peptide RLRDLLLIVTR has been shown by others to be presented to CTL by HLA-A3.1. Autologous virus sequences from seroconversion and up to 15 wk after presentation in these two patients were recognized by the CTL clones isolated during acute infection. None of the CTL clones recognized the MN strain of HIV-1, indicating the problems inherent in relying on a single virus strain in the development of a vaccine. These studies have identified an immunodominant and promiscuous area for the generation of CTL responses within gp41. This recognition of autologous virus sequences by the initial CTL response is consistent with the hypothesis that a single virus strain is transmitted to the seroconverter and that the CTL response is involved in the initial control of that virus. These studies indicate the importance of the CTL response to HIV-1 infection and have implications in the design of vaccines.

Transsphenoidal microsurgical management of pituitary adenomas

The transsphenoidal microsurgical operation is the best choice for most pituitary adenomas, whether or not there is an extension into the sphenoid or a supra-sellar extension without lateral spread. The advantage of this approach is that it allows selective removal of the adenoma and therefore can preserve normal pituitary function. In our series of 249 cases 79% had achieved a remission at follow-up one year or more after surgery. The surgical failure rate was 21%, and the mortality rate 0.8%. Complications occurred in 5.6%; most were temporary and minimal. The recurrence rate after transsphenoidal microsurgery was lower than that quoted in the literature after craniotomy. The smaller the size of the adenomas and the less the hormone abnormality preoperatively, the better the outcome.

Genotypic and phenotypic characterization of HIV-1 patients with primary infection

Better characterization of human immunodeficiency virus-type 1 (HIV-1) in patients with primary infection has important implications for the development of an acquired immunodeficiency syndrome (AIDS) vaccine because vaccine strategies should target viral isolates with the properties of transmitted viruses. In five HIV-1 seroconverters, the viral phenotype was found to be uniformly macrophage-tropic and non-syncytium-inducing. Furthermore, the viruses were genotypically homogeneous within each patient, but a common signature sequence was not discernible among transmitted viruses. In the two cases where the sexual partners were also studied, the sequences of the transmitted viruses matched best with minor variants in the blood of the transmitters. There was also a stronger pressure to conserve sequences in gp120 than in gp41, nef, and p17, suggesting that a selective mechanism is involved in transmission.

Thermodynamic, thermomechanical, and structural properties of a hydrated asymmetric phosphatidylcholine

1-Behenyl-2-lauryl-sn-glycero-3-phosphocholine (22/12 PC) belongs to a unique group of phospholipids in which the molecule has one acyl chain almost twice as long as the other. The temperature-composition phase diagram for this lipid in the range of 25-65 degrees C, and 0 to 84.3% (w/w) water has been constructed by using the isoplethal method in the heating direction and x-ray diffraction for phase identification and structure characterization. At water contents between 10.3 and 34% (w/w) and at temperatures below 43 degrees C, a single mixed interdigitated lamellar gel phase (Lm beta, [symbol: see text]) of the type described by Hui et al. (1984. Biochemistry. 23:5570-5577) and McIntosh et al. (1984. Biochemistry. 23:4038-4044) was found. A second phase consisting of bulk aqueous solution coexists with the Lm beta phase at hydration levels above 34% (w/w) water in the temperature range between 25 and 43 degrees C. Above 43 degrees C, a partially interdigitated lamellar liquid crystalline (Lp alpha) phase ([symbol: see text]) is seen in the water concentration range extending from 0 to 84.3% (w/w). The pure Lp alpha phase is found below 43% (w/w) water, while coexistence of the Lp alpha phase and the bulk aqueous solution is observed above this water concentration which marks the hydration boundary. Interestingly, the latter boundary for both Lm beta and Lp alpha phases is nearly vertical in the temperature range studied. Furthermore, the lamellar chain-melting transition temperature appears to be relatively insensitive to hydration in the range 0-85% (w/w) water. We have confirmed the identify of the Lm beta phase by constructing a 5.7-A resolution electron density profile on oriented samples by the swelling method. Temperature-induced chain melting effects an increase in lipid bilayer thickness suggesting that the Lp alpha phase has chains packed in the partially as opposed to the mixed interdigitated configuration. Unlike the symmetric phosphatidylcholines a ripple (P beta') phase was not found as an intermediate between the low and high temperature lamellar phases of 22/12 PC. The specific volume of 22/12 PC is 940 (+/- 1) microliter/g and 946 (+/- 1) microliter/g in the hydrated lamellar gel state at 28 (+/- 2) and 40 (+/- 2) degrees C, respectively, from neutral buoyancy experiments. Based on measurements of the temperature dependence of the various lattice parameters of the different phases encountered in this study the corresponding lattice thermal expansion coefficients have been measured. These are discussed and their dependence on lipid hydration is reported.

Alterations in activities of protein phosphatases PP1 and PP2A in T and B lymphocytes of autoimmune MRL/MpJ-lpr/lpr mice

Activities of protein phosphatases PP1 and PP2A were determined in T and B lymphocytes of autoimmune-prone MRL/MpJ-lpr/lpr mice (MRL/lpr mice) and two control strains, MRL/MpJ-(+)/+ mice (MRL/+/+ mice) and C3H/HeJ mice. Potential PP1 activity, which was measured after treatment of cell extract with Co(2+)-trypsin, was much higher in T lymphocytes than B lymphocytes. However, no difference in the activity was observed between MRL/lpr mice and the controls. Spontaneous PP2A activity showed similar levels in T and B lymphocytes from normal mice, but potential PP2A activity, which was measured after treatment with 2-mercaptoethanol, was significantly higher in T lymphocytes from MRL/lpr mice than those from controls. No differences were detected in PP1 or PP2A activities in B lymphocytes. From these results, our previous data [Matsuzawa, S. et al. (1992) J. Biochem. 111, 472-477] demonstrating increases in potential activities of PP1 and PP2A in lymphoid tissues from autoimmune MRL/lpr mice can be interpreted as follows. 1) The increase in potential PP1 activity of the lymphoid tissues from MRL/lpr mice is caused by replacement of B lymphocytes by abnormal T lymphocytes, which accumulate in enormous numbers. 2) The increase of potential PP2A activity in the lymphoid tissues from MRL/lpr mice is caused by the increase in this activity in their T lymphocytes.