Biomedical subjects
L He
Publications and source records attributed to L He.
Primary-structural and evolutionary analyses of the growth-hormone gene from grass carp (Ctenopharyngodon idellus).
The growth-hormone (GH) gene of grass carp, one of the fastest-growing species of farmed fish, was isolated and the DNA sequenced. Only one GH gene is found in this species. This gene, which is 2.5 kb in length, has five exons and four introns, in common with all of the mammalian and the recently published common-carp GH genes. In the course of vertebrate evolution, the total lengths of the intron and the non-coding region of exon 5 of the GH gene have been shortened by 40-70%, whereas the encoding exons of the gene have been slightly increased. The more closely related species exhibit the closest sequence similarity in their GH genes. For example, the similarity of the exons is 84.1-93.2% between grass carp and common carp (within the same family of Syprinedae), 43.5-82.1% between grass carp and rainbow trout (in different orders of Teleostei) and 45.8-58.6% between grass carp and rat (in different grades of Vertebrata). In addition, similar DNA domains, such as thyroid-hormone-receptor-complex-binding site and cell-type-specific cis elements involved in regulation of expression of rat and human GH genes, have been localized in the corresponding regions of the grass-carp GH gene.
Association of 2'-5' oligoribonucleotides.
Oligoribonucleotides with 2'-5' linkages have been synthesized on solid support. UV melting and CD experiments indicate complementary strands associate to give complexes with melting temperatures 30 to 40 degrees C lower than for duplexes formed by 3'-5' oligoribonucleotides with the same sequence. UV melting and imino proton NMR spectra and NOEs for (2'-5') CGGCGCCG are consistent with formation of an antiparallel duplex. The results suggest greater duplex stability was one factor favoring 3'-5' over 2'-5' linkages in evolution.
Triterpenoids and Steroids from Aster poliothamnus.
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Two Saccharomyces cerevisiae kinesin-related gene products required for mitotic spindle assembly.
Two Saccharomyces cerevisiae genes, CIN8 and KIP1 (a.k.a. CIN9), were identified by their requirement for normal chromosome segregation. Both genes encode polypeptides related to the heavy chain of the microtubule-based force-generating enzyme kinesin. Cin8p was found to be required for pole separation during mitotic spindle assembly at 37 degrees C, although overproduced Kip1p could substitute. At lower temperatures, the activity of at least one of these proteins was required for cell viability, indicating that they perform an essential but redundant function. Cin8p was observed to be a component of the mitotic spindle, colocalizing with the microtubules that lie between the poles. Taken together, these findings suggest that these proteins interact with spindle microtubules to produce an outwardly directed force acting upon the poles.
Sickle and thalassemic erythroid progenitor cells are different from normal.
Blood erythroid progenitors (BFU-E) from patients with sickle and thalassemic syndromes were compared with those from normal individuals. The day of maximal colony formation in methyl cellulose was slightly later in the cultures from the patients with hemoglobinopathies than in the normal cultures. The number of colonies/100,000 mononuclear cells was similar in all cultures on day 13, but was higher in the hemoglobinopathy cultures on the day of maximal growth. The number of BFU-E/mL of blood was significantly higher than normal at all times in both sickle cell anemia and thalassemia. The proportional synthesis of gamma globin was twice normal in all sickle cultures, and 4 times normal in those from beta+-thalassemia. Hemin and interleukin-3 increased the numbers of erythroid colonies in all cultures, but did not consistently alter the globin synthesis patterns. Each progenitor population has a unique pattern in terms of time course, number of BFU-E, and level of gamma globin synthesis. These features indicate distinct types of BFU-E, or differences in accessory cells, or both, which distinguish blood-borne erythropoiesis in normals and those with hemoglobinopathies.
Electroacupuncture enhances activity of adrenal nucleolar organizer regions in ovariectomized rats.
Nucleolar organizer regions (NORs) may reflect the activity of cell differentiation and transcription of nucleolar rDNA; the present paper studied nucleolar organizer regions of the adrenal cortex to explore the regulatory effect of electroacupuncture (EA). Animals were divided into four groups, the ovariectomized electroacupuncture group (OV+EA group, n = 7), the ovariectomized group (OV group, n = 4), the EA group (n = 3) and the control group (CT group, n = 4). Number of AgNORs of 100 cells from zona fasciculata of the adrenal cortex in each case of the four groups was counted at random and the mean+/-SE (number/cell) in each group was calculated as follows: OV+EA group, 2.71 +/- 0.26, OV group, 1.26 +/- 0.15, EA group, 1.21 +/- 0.04 and CT group, 1.48 +/- 0.03. The mean of AgNORs in OV+EA group differed highly significantly from the other three groups (p less than 0.01) as tested with ANOVA and LSD method. No significant difference was found among the other three groups. Gross specimen examination showed that adrenals in the OV+EA group were significantly heavier than those in the other three groups (p less than 0.01). Vaginal smears showed that a response like estrogen-induced one with exfoliative cells appeared in the OV+EA group. EA had no significant effect on normal rats. The results suggest that EA may promote the synthesis and secretion of adrenal steriod hormones, the androgen of which will then be transformed into estrogen in other tissues, thus compensating the deficiency of estrogen induced by ovariectomy.
Alterations of spinal dorsal horn substance P following electroacupuncture analgesia--a study of the formalin test with immunohistochemistry and densitometry.
Substance P (SP), released from thin afferent terminals, is believed to be a neurotransmitter for pain transmission in the spinal dorsal horn. It has been demonstrated that in addition to analgesia, morphine increases the accumulation of SP possibly due to the inhibition of its release. The present work investigated the level of spinal SP like immunoreactivity (SPLI) following electroacupuncture analgesia in rats using immunohistochemistry and image analysis. Experiment results revealed that formalin injected into the hind paw elicited marked pain response and accumulation of SP in the spinal dorsal horn. Electroacupuncture of Tsu-San-Li could depress the pain response, however increasing further the SP accumulation. It is thus suggested that pain stimulation itself may activate the endogenous opioid mechanism to inhibit SP release and acupuncture is able to enhance the process. This may be one mechanism of acupuncture analgesia.
Characterization of AluI repeats of zebrafish (Brachydanio rerio).
Two families of repetitive DNA sequences were isolated from the zebrafish genome and characterized. Eight different sequences were sequenced and classified by two standards, their (G + C) composition and their lengths. For convenience, the sequences were first divided into two types. Type I was (A + T)-rich, was repeated approximately 500,000 times, and constituted approximately 5% of the zebrafish genome. Type II was (G + C)-rich, was reiterated approximately 90,000 times, and comprised approximately 0.5% of the genome. Agarose gel electrophoresis of zebrafish DNA cleaved with AluI revealed three distinguishable bands of repetitive fragments: large (approximately 180 bp, designated RFAL), medium (approximately 140 bp, RFAM), and small (approximately 90 bp, RFAS). The RFAL fragments contained both type I and type II sequences. Limited digestion of genomic DNA indicated that RFAL and RFAM were tandemly arranged in the genome, whereas RFAS showed a mixed pattern of both tandem and interspersed repeated arrangements. Although inclusion of a repetitive sequence in a transgenic construct did not appreciably accelerate homologous integration of transgenes into the zebrafish genome, the AluI sequences could facilitate transgene mapping following chromosomal integration.
Pure rhabdomyosarcoma of the corpus uteri in a postpartum patient: report of a case and review of the literature.
Pure rhabdomyosarcomas originate in the female genital tract. They are uncommon and most often occur in infancy or childhood as sarcoma botryoides (embryonal rhabdomyosarcoma) which involve the vagina and cervix. Such tumors rarely occur in adults. A pure rhabdomyosarcoma of the uterus that arose in a postpartum patient is described. The pertinent literature is discussed.
[Study of quantitative diagnosis of cerebral arteriosclerosis].
On the basis of clinical diagnostic criterion of cerebral arteriosclerosis, we selected, 72 patients with cerebral arteriosclerosis, 72 patients with suspected cerebral arteriosclerosis and 70 healthy individuals and screened 42 variables obtained from clinical and accessory examination with a stepwise discriminant analysis and a stepwise regression analysis. Finally we performed a logistic discriminant analysis of 15 selected variables in order to establish diagnostic discriminant formulas, Ya and Yc. It was found that a diagnostic coincidence rate for rediscriminant analysis of 212 individuals with the formulas was 100%. Very high sensitivity (96.7%), specificity (100%), positive predicted value (100%), negative predicted value (83.3%) and accuracy (97.1%) were noted in a prospective double-blind test on 34 subjects. The authors suggest that the discriminant formulas Ya and Yc established for diagnosis of cerebral arteriosclerosis be widely applicated.
[Allotransplantation of meniscus in dog's knee. An experimental study].
This experimental study was to show the difference and outcome of allotransplantation and autotransplantation of meniscus in dogs. In the experimental group (9 dogs), the lateral meniscus was removed and replaced by one preserved for 2 weeks in tissue culture. In the control group (9 dogs), the lateral meniscus was excised but was sutured back to the place immediately. The specimens in each group were taken at 3, 6, 12, and 24 weeks after operation, and were examined microangiographically and histologically under light microscope and electron microscope. The results in both groups showed that the meniscus united to the capsule, chondrocytes in the menisci were intact and the collagen fiber orientation was regular. The articular cartilage of the uncovered area of the tibial plateaus showed normal appearance, and vascular neogenesis in the meniscal periphery was found 12 weeks after operation. These observations suggest that allogenic meniscus maintains its original histologic pattern and functional behavior after its transplantation. It makes possible to protect the knee joint from osteoarthritis.
Nearest-neighbor parameters for G.U mismatches: [formula; see text] is destabilizing in the contexts [formula; see text] and [formula; see text] but stabilizing in [formula; see text].
Thermodynamic parameters derived from optical melting studies are reported for duplex formation by a series of oligoribonucleotides containing G.U mismatches. The results are used to determine nearest-neighbor parameters for helix propagation by G.U mismatches. Surprisingly, the [formula; see text] nearest-neighbor free energy increment in unfavorable in the contexts [formula; see text], and [formula; see text] but favorable in the context [formula; see text]. This is a non-nearest-neighbor effect. In contrast, the [formula; see text] free energy increment is favorable and independent of context. Circular dichroism and imino proton NMR spectra of several sequences do not reveal an obvious structural basis for this dichotomy. For example, all the G.U mismatches have two slowly exchanging imino protons. The imino resonances for the G.U mismatches in GGAGUUCC, GUCGUGAC, and CCUGUAGG, however, broaden at lower temperature than the imino resonances for the interior Watson-Crick base pairs. In contrast, the imino resonances for the G.U mismatches in GGAUGUCC remain sharp at high temperature. The improved parameters for G.U mismatches should improve predictions of RNA structure from sequence.
Absolute cross sections for the photoionization of the 6s6p 1P excited state of barium.
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Modulation of endothelial cells fibrinolytic activity by platelets.
Interaction between endothelial cells (EC) and platelets in culture was shown to regulate the fibrinolytic system of the aortic EC. Untreated porcine EC from aorta exhibited almost no net fibrinolytic activity and zymographic assay have shown a single fibrin lysis band of 105 kDa corresponding to a tPA-PAI complex. Incubation of aortic EC with intact platelets stimulated a cell-associated fibrinolytic activity of the urokinase type as evidenced by a plasminogen-dependent fibrin independent amidolytic activity, and the appearance of a new 48 kDa lysis band on zymography. However, in the culture medium of platelet-treated aortic EC, a new lysis band of 92 kDa appeared with no associated amidolytic activity suggesting that the 48 kDa plasminogen activator secreted by the aortic EC after treatment with platelets is complexed to the inhibitor PAI1. This modulation of fibrinolytic activity depends on the EC origin since it is not observed with pulmonary artery EC, and represents a new concept in fibrinolysis regulation by cell-cell interaction.
Localization and in vitro actions of atrial natriuretic peptide in the cat carotid body.
Previous studies of atrial natriuretic peptide (ANP) have indicated that its release from the heart and from discrete areas of the central nervous system evokes coordinated physiological and behavioral adjustments that mitigate the adverse hypertensive effects of volume overload and/or acute increases in sodium intake. Because the reflex activity initiated by arterial chemoreceptors of the carotid body directly contributes to the integrated regulation of systemic blood pressure, we have investigated the possibility that ANP has a significant role in the chemosensory process as well. Our immunocytochemical studies show that ANP-like immunoreactivity is present in the preneural chemosensitive type I cells in the cat carotid body. Furthermore we found that the biologically active ANP fragment atriopeptin III is a potent inhibitor of carotid sinus nerve activity evoked by hypoxia. Our findings suggest that circulating and/or endogenous ANP may modulate carotid body function as part of a coordinated response to changes in systemic volume and solute balance.
A survey analysis of the effects of the home environment on cultural quality.
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[Special attention to the diagnosis and treatment of immunodeficiency].
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