A note on "An economic approach to abortion demand.".
Explore the source record for details and available documents.
Abortion, Induced↗
Biomedical subjects
W Sun
Publications and source records attributed to W Sun.
Midbrain paralemniscal projections to the facial nucleus: an anatomical and immunohistochemical study.
Serial 30 microns-thick sections through the midbrain tegmentum were stained with cresyl violet. The PL was found to be situated along the medial edge of the lateral lemniscus. The PL consisted of small- (10-15 microns) and medium-sized neurons (25-35 microns), and was the most prominent at the caudal level of the superior colliculus. In order to confirm the existence of the inhibitory paralemniscal-facial pathway, a combined HRP and immunohistochemical technique was use in the rat. This experiment revealed that 10.9% of the total number of GABA immunoreactive PL neurons also labeled with HRP after HRP injection was made in the medial part of the facial nucleus (FN). Electron microscopic observations were carried out on the medial part of the facial nucleus (FN) after kainic acid injection was made into the contralateral PL in the cat. The majority of degenerating PL fibers were ranged from 0.5 to 3.1 microns in diameter and made synaptic contacts with somata, proximal dendrites and dendritic profiles. These fibers, containing either round or pleomorphic vesicles, formed asymmetrical or symmetrical synapses. It was of particular interest in the present study that 40.7% of the total number of degenerating fibers make synaptic contacts with large dendrites more than 3.0 microns in diameter.
Animals↗
Ultrastructure of spinal relay of hypoglossal afferents to the parabrachial nucleus.
Wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) injection into the hypoglossal nerve mainly resulted in retrograde labeling in the superior ganglia of the glossopharyngeal and vagal nerves ipsilaterally. Anterogradely labeled fibers were found in lamina I of the ipsilateral upper cervical spinal cord with a few distribution to laminae IV-V and VII-VIII. WGA-HRP injection into the PBN revealed intensive labeling of lamina I neurons of the upper cervical spinal cord ipsilaterally. These light microscopic observations appear to indicate the hypoglossal sensory inputs to the PBN through the spinal cord. In order to investigate the synaptic nature of this spinal relay, electron microscopic observations were carried out on lamina I of the first and second cervical spinal cord after cutting the hypoglossal nerve and WGA-HRP injection into the PBN in the same animal. The spinoparabrachial projection neurons were demonstrated to show a low cytoplasmic/nuclear ratio and have an oval or deeply indented nucleus with a centrally located nucleolus. Furthermore, dark and light type degenerating fibers were observed to make synaptic contacts with HRP-labeled somata and dendritic profiles.
Afferent Pathways↗
Hypoglossal afferents to lamina I neurons of the cervical spinal cord projecting to the parabrachial nucleus in the cat.
Attempts were made to determine the hypoglossal sensory inputs to the parabrachial nucleus (PBN) through the spinal cord. Wheatgerm agglutinin conjugated to horseradish peroxidase (WGA:HRP) was injected into the cat hypoglossal nerve. HRP-labeled fibers, predominantly derived from the glossopharyngeal and vagal nerves, were observed to terminate in lamina I of the upper cervical spinal cord. A few fibers were also distributed to laminae IV-V and VII-VIII ipsilaterally. WGA:HRP injection into the lateral portion of the PBN also resulted in retrograde labeling in lamina I with ipsilateral predominance. Light-microscopic data raised the possibility of a relay of hypoglossal sensory information to the PBN in lamina I of the cervical spinal cord. In order to confirm the spinal relay, electron-microscopic observations were carried out on lamina I of C1 spinal cord after sectioning of the hypoglossal nerve and WGA:HRP injection into the lateral portion of the PBN on the same side in each animal. It was of particular interest that degenerated hypoglossal afferent fibers made synaptic contacts with lamina I neurons, which were retrogradely labeled with HRP.
Afferent Pathways↗
Treatment of intracranial germinoma.
In 31 patients with intracranial germinoma who received radiotherapy, 15 were operated on, and 13 were treated with CSF shunt (7) and external ventricular drainage (6). After radiotherapy, clinical symptoms were improved in 93.5% of the patients. Follow-up of 16 patients for 2 to 14 years showed better results. We consider that initial treatment with radiotherapy may be appropriate for germinomas because of its high radiosensitivity. If hydrocephalus developed, external ventricular drainage combined with radiotherapy was performed, but shunting operation might be avoided because of potential peritoneal seedings of germinomas. In addition to chemotherapy, re-irradiation is an effective method for recurrent germinoma.
Adolescent↗
[Quantitative analysis of serum hyaluronic acid and its application in liver disease].
Determination of serum hyaluronic acid (HA) in 191 normal subjects and 170 cases with liver disease found, due to containing a large amount of HA in fetal tissues, serum HA level in neonates still remained relatively high, and decreased gradually with their growth and approximated to adult level by the age of six months. Serum HA level increased significantly in patients with liver disease and showed no change in chronic persistent hepatitis. The gradient trend of increasing serum HA levels in patients with liver disease was acute hepatitis, chronic active hepatitis, and cirrhosis of liver. Determination of serum HA would be conducive to evaluation of the degree of liver injuries and could be used in large-scale epidemiological studies and screening-up with low-cost and quickness, with an upper reference value of 117 micrograms/L.
Adolescent↗
[Effect of electroacupuncture on the discharges of pain-sensitive neurons in the hypothalamic dorsomedial nucleus of rats].
The discharges of pain-sensitive neurons of the hypothalamic dorsomedial nucleus (DMH) in Sprague-Dawley rats were recorded with glass microelectrodes, After electroacupuncture acupoints "Zusanli" and "Sanyinjiao", the rate of spontaneous discharges and the rate and duration of the pain-evoked discharges of pain-excitatory units of DMH were profoundly decreased, and the spontaneous firing rate of pain-inhibitory units was increased while their inhibitory response to nociceptive stimulation was released by the electroacupuncture. The results mentioned above suggest that DMH participates in the activity of acupuncture analgesia.
Acupuncture Analgesia↗
[The case-control study of risk factors in primary angle-closure glaucoma].
A case-control study was conducted to determine the risk factors of primary angle-closure glaucoma (PACG). In this study, 103 cases of PACG patients and 95 cases of non-glaucoma controls were investigated. It was found that the risk factors of PACG were family history of glaucoma, irritable temper, short distance between eyes and workplace at work and high blood pressure. The results did not support that cigarette smoking, alcoholic consumption, diabetes mellitus, myopia and blood types were related with PACG.
Adult↗
Changes in sodium intake and blood pressure in a community-based intervention project in China.
A sodium intervention project was carried out in Tianjin, China, as part of the Tianjin Project, which is a national pilot, community-based intervention programme to reduce non-communicable diseases. The aim of this 3 year sodium project was to evaluate the feasibility and effects of sodium reduction in the population. The evaluation of the programme was based on examinations of independent cross-sectional population samples in 1989 (1719 persons) and in 1992 (2304 persons) in the intervention and matched reference areas. Food weighing and consecutive 3 day food records were used to measure dietary intake. The mean sodium intake fell 22 mmol/day in men and 11 mmol/day in women in the intervention area from 1989 to 1992. The reduction was significant in men (P = 0.001) and near significance in women (P = 0.05). The sodium intake increased significantly in men in the reference area. There was a significant net reduction in sodium intake in men in the intervention area. This reduction was similar in different educational and occupational groups suggesting that the intervention had reached the whole community. The mean systolic blood pressure (SBP) decreased 3 mm Hg for the total population and 2 mm Hg for normotensives in the intervention area. There was a significant net reduction in SBP both in all or in normotensive subjects. These results support the conclusion that community-based sodium intervention is feasible for hypertension prevention. However, the sodium intake is still very high in this population, which warrants further effective intervention.
Adolescent↗
Domains of Escherichia coli primase: functional activity of a 47-kDa N-terminal proteolytic fragment.
Endoproteinase Asp-N cleaves the 581-amino acid Escherichia coli primase (65,564 Da) into several major fragments. One of these, a 47-kDa fragment containing the complete N terminus and the first 422 amino acids of primase, is capable of primer RNA (pRNA) synthesis in the G4oric/single-stranded DNA binding protein/primase pRNA synthesis system. A cloned 398-amino acid N-terminal fragment of primase can also synthesize pRNA. The sizes of the pRNA synthesized by these N-terminal fragments, however, are smaller than those synthesized by intact primase, suggesting that the C-terminal region of primase plays a role in processivity or regulation of pRNA synthesis. Primase mutants with the last 10 and 40 C-terminal amino acids deleted synthesize pRNA as wild-type primase, indicating that any regulatory sequences must be internal to the C terminus of primase.
Amino Acid Sequence↗
Biosynthesis of poly-3-hydroxybutyrate in the luminescent bacterium, Vibrio harveyi, and regulation by the lux autoinducer, N-(3-hydroxybutanoyl)homoserine lactone.
Poly-3-hydroxybutyrate (PHB), a biopolymer of important commercial applications, is found in a wide range of Gram-negative and Gram-positive bacteria and cyanobacteria. The present study has resulted in the identification of PHB in the luminescent marine bacteria, Vibrio harveyi, in spite of it being previously classified as PHB-negative. PHB granules with distinct membranes were detected by electron microscopy after fixation and staining of V. harveyi cells with malachite green. Analyses by gas chromatography, nuclear magnetic resonance, infrared, and ultraviolet spectroscopy clearly established the presence of PHB. The synthesis of PHB in V. harveyi was found to be under cell density regulation with the levels increasing from 0 (< 0.2) to 26 mg of PHB/g of dry cell weight during growth in a manner analogous to the induction of luminescence in this bacteria. Moreover, synthesis of PHB in V. harveyi was shown to be controlled by the lux autoinducer, N-(3-hydroxybutanoyl)homoserine lactone, providing not only a potential link between luminescence and PHB production but also showing that the lux autoinducer acts as a general signal transductant. These results have also extended the role of homoserine lactones in metabolic regulation to include the control of synthesis of potential energy reserves.
4-Butyrolactone↗
Presence of gonadotropin-releasing hormone mRNA in the rat olfactory piriform cortex.
Gonadotropin releasing hormone (GnRH) neurons are known to be originated from the olfactory placode and to enter the forebrain regions during embryonic development. The present study aims to ascertain whether GnRH is locally expressed in the olfactory cortex. Northern blot hybridization and reverse transcription-polymerase chain reaction revealed that GnRH mRNA was present in the rat olfactory cortex as well as in the olfactory bulb. The predicted size of GnRH mRNA is similar to that detected in the hypothalamus. In situ hybridization histochemistry also showed that GnRH mRNA is highly concentrated in the olfactory piriform cortex. The present data indicate that GnRH is synthesized in the olfactory piriform cortex.
Animals↗
Andreev reflections on heavy-fermion superconductors.
Explore the source record for details and available documents.
Journal Article↗
Unusual B-T phase diagram of the heavy-fermion superconductor CeCu2Si2.
Explore the source record for details and available documents.
Journal Article↗
Production of mouse V/human C chimeric kappa genes by homologous recombination in hybridoma cells. Analysis of vector design and recombinant gene expression.
Homologous recombination between transferred and chromosomal Ig genes in mouse hybridoma cells offers a general method of altering the chromosomal Ig genes in predetermined ways. Recombination is infrequent in hybridoma cells, and we have been interested in improving the methods for identifying and recovering the rare recombinants. We have used vectors that are designed to replace the mouse chromosomal C kappa segment with the human equivalent, so that recombinants produce mouse V/human C chimeric kappa-chains. We describe an enhancerless, replacement type vector that can be used with the herpes thymidine kinase counterselection to provide such enrichment that homologous recombinants constitute 15% of the selected G418-resistant, FIAU-resistant cells. We have also measured the level of chimeric kappa gene expression and found surprisingly that (1) it is very variable among transformants with the same recombinant gene structure, (2) there is no systematic difference in the level of production by recombinants that retain or have lost the J-C kappa intron enhancer, and (3) the amount of chimeric kappa mRNA in even the highest producing transformants is much less than the amount of the corresponding mouse kappa mRNA.
Animals↗
Primary structure and functional expression of the AMPA/kainate receptor subunit 2 from human brain.
A full-length cDNA clone encoding the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate (KA) receptor subunit 2 (HBGR2) was isolated from a human brain cDNA library. The HBGR2 cDNA has an open reading frame of approximately 2.7 kb that codes for an 883-residue protein. At the amino acid level, HBGR2 is 98% identical to its rat counterpart GluR2, and 69% to the AMPA/KA receptor subunit 1 from human brain (HBGR1). Injection of cRNA transcripts from the HBGR2 into oocytes produces barely detectable kainate-activated ionic currents, indicating that the HBGR2 subunit alone weakly expresses homomeric receptor channels. Coexpression of HBGR2 and HBGR1 transcripts, however, evokes kainate-dependent currents which activate at higher agonist concentration than those required by homomeric HBGR1 receptor channels. Coexpressed receptors display a linear current-to-voltage relationship at variance with the inwardly rectifying profile exhibited by HBGR1 homomers. Hence, the HBGR2 subunit coassembles with the HBGR1 subunit to form heteromeric receptor channels akin to the glutamate receptors from rodent brain.
Amino Acid Sequence↗
Synthesis, surface, and cell-adhesion properties of polyurethanes containing covalently grafted RGD-peptides.
In an attempt to improve endothelial cell adhesion and growth on a polyurethane copolymer, cell adhesive RGD-containing peptides were grafted to the polymer backbone. Two peptide grafting reaction schemes, including one-step and two-step approaches, were developed. FTIR and amino acid analysis confirmed that coupling of the peptide to the polyurethane backbone was achieved by both the one-step and two-step methods. However, the two-step approach showed a higher peptide coupling efficiency and resulted in better control of the orientation of the grafted peptide. The two-step reaction scheme was used to prepare Gly-Arg-Gly-Asp-Ser-Tyr (GRGDSY), Gly-Arg-Gly-Asp-Val-Tyr (GRGDVY), and Gly-Arg-Gly-Glu-Ser-Tyr (GRGESY) peptide-grafted polyurethanes with two different peptide densities (100 and 250 mumol/g polymer). Dynamic contact angle measurements indicated that the surfaces of the peptide-grafted polyurethanes were more hydrophilic than the starting and carboxylated versions of the precursor polyurethane. In addition, the surface hydrophilicity of the peptide-grafted polymers increased with increasing bulk peptide density. Electron spectroscopy for chemical analysis suggested that the grafted peptide was present at the polymer-air interface, in vacuo, for the peptide-grafted polyurethanes. The surface peptide density appeared to correlate with the incorporated peptide density in the bulk. In vitro endothelial cell adhesion experiments showed that, without the presence of serum in culture medium, the GRGDSY- and GRGDVY-grafted polyurethanes dramatically enhanced cell attachment and spreading compared with the starting, carboxylated, and GRGESY-grafted polymers. Increasing the peptide density from 100 to 250 mumol/g polymer for the GRGDSY- and GRGDVY-grafted polyurethanes resulted in an increase in cell attachment. With approximately the same peptide density (100 or 250 mumol/g polymer), the GRGDVY-grafted polymers supported more adherent cells than did the GRGDSY-grafted polymers. Similar trends were observed in the in vitro endothelial cell growth studies using culture medium containing serum and endothelial cell growth supplement. The GRGDSY- and GRGDVY-grafted polyurethanes promoted more cell growth than did the starting polyurethane. However, the presence of adhesive serum proteins and growth factor diminished the differences between the cell-adhesive peptide grafted polymers and the GRGESY-grafted polymers.
Amino Acid Sequence↗
Analysis of thymidine kinase gene expression in preimplantation mouse embryos.
Thymidine kinase (TK) activity was examined during the development of preimplantation mouse embryos. TK activity was increased approximately 20-fold from day 2 embryos (2-cell) to day 5 embryos (late blastocyst). TK activity did not change along with the progression into S-phase of the first and the second cell cycles but increased sharply at S-phase of the third cell cycle. Analysis of TK mRNA with a reverse transcription-polymerase chain reaction (RT-PCR) method showed that the level of TK mRNA was low in ovulated eggs and 1-cell embryos and was hardly detectable in day 2 embryos (2-cell), but sharply increased in day 3 embryos (mixture of 5- to 8-cell and morula). The functional role of 5'-flanking sequence of TK gene was also investigated in preimplantation embryos after microinjection with the DNA construct of 5'-flanking sequence of TK (2.4 kb) linked to bacterial lacZ gene (TK2.5lacZ) into the pronucleus of 1-cell and subsequently by histochemical staining with X-gal. beta-Galactosidase activity was first detected in day 3 embryos (8-cell), and 30% of embryos were stained with X-gal in day 4 and day 5 embryos, respectively. These results show that an increase in TK activity occurred after 2-cell stage, and this increase was primarily due to the embryonic activation of TK gene expression. Also, it appears that the 5'-flanking sequence of TK may directly regulate the TK gene expression at the transcriptional level during preimplantation murine development.
Animals↗