Archaic structure of the gene encoding transcription factor USF

The upstream stimulatory factor (USF) is a helix-loop-helix transcription factor that interacts with specific sites on the DNA that are also recognized by the MYC oncoproteins. We isolated genomic clones to the murine 44-kDa form of USF (USF2 gene). This unique gene spans 13 kilobases of DNA and is composed of 10 exons. The gene seems to have maintained its archaic structure, since many of the exons encode discrete functional domains of the transcription factor originally identified by protein sequence comparisons. A particularly striking HpaII tiny fragment island, extending over nearly 2,000 base pairs, surrounds the USF2 translation initiation site. This region, which includes the USF2 promoter and the first four exons, is characterized by an overall GC content greater than 74%. Analysis by S1 mapping and transient transfection assays revealed that the USF2 transcripts originate from an initiator element located within a highly GC-rich region that is surrounded by two long polyadenylate stretches and functions as a bidirectional promoter. Different forms of USF2 messages result from the presence or absence of the fourth exon in the processed USF2 mRNA. Alternative splicing correlates with the lack of a consensus lariat branch point in the third intron. Transient cotransfection assays revealed that the presence or absence of the amino acid sequences encoded by exon 4 affects considerably the transcription activation properties of the USF2 protein.

Glycine and GABAA antagonists reduce the inhibition of primate spinothalamic tract neurons produced by stimulation in periaqueductal gray

Amino acids are demonstrated to be important neurotransmitters mediating the inhibitory transmission from nucleus raphe magnus to spinal nociceptive dorsal horn neurons. In this study, the role of glycine and GABA in the inhibitory processes evoked by stimulation in periaqueductal gray (PAG) of responses of primate spinothalamic tract (STT) neurons to cutaneous mechanical and thermal stimuli was investigated by examining the effects of strychnine and bicuculline, antagonists of glycine and GABAA receptors, respectively, introduced into the dorsal horn through a microdialysis fiber. The inhibitory effects of iontophoretic application of glycine and GABAA agonists on STT cell activity evoked by noxious mechanical stimulation of the skin were selectively blocked by their specific antagonist, strychnine or bicuculline, infused into the dorsal horn. Similarly, intra-spinal application of strychnine or bicuculline resulted in a significant reduction in the PAG stimulation-induced inhibition of responses of STT cells to cutaneous stimuli. This reduction was mainly on the PAG-induced inhibition of the responses to noxious mechanical stimuli. Our results suggest that glycinergic and GABAergic inhibitory interneurons in the spinal cord dorsal horn synapsing on STT cells are activated during stimulation in PAG and contribute to descending antinociceptive actions.

Isolation and characterization of cDNA clones for chloroplast translational initiation factor-3 from Euglena gracilis

A complete cDNA clone encoding Euglena gracilis chloroplast translational initiation factor 3 (IF-3chl) has been obtained. Analysis of the sequence indicates that the IF-3chl mRNA contains the spliced leader found at the 5' end of nuclear encoded mRNAs in E. gracilis. The open reading frame for IF-3chl encodes a 537-amino acid protein. IF-3chl appears to be divided into four domains. The first 140 amino acids correspond to a transit peptide required for the import of IF-3chl into the chloroplast. The mature form of IF-3chl encompasses domains 2-4 and is about twice the size of Escherichia coli IF-3. The second domain has no homology to other known proteins. It begins with a stretch of 35 residues, of which about 30% are proline. Downstream from this region is a stretch of about 25 amino acids with a repeating (GX)n motif followed by a very acidic region. The third domain comprises a region of about 175 residues and has between 31 and 37% homology to the IF-3s found in other organisms. The IF-3 homology domain is followed by an acidic region which has no detectable homology to other sequences. Analysis of E. gracilis genomic DNA suggests that there are about four copies of the IF-3chl gene, one of which is probably a pseudogene. The activity of IF-3chl is inducible by light. However, the IF-3chl mRNA is present in approximately equal amounts in both dark- and light-grown cells, suggesting that the light-dependent induction of IF-3chl activity is post-transcriptional.

Ubiquitous expression of the 43- and 44-kDa forms of transcription factor USF in mammalian cells

USF is a helix-loop-helix transcription factor that, like Myc, recognizes the DNA binding motif CACGTG. Two different forms of USF, characterized by apparent molecular weights of 43,000 and 44,000, were originally identified in HeLa cells by biochemical analysis. Clones for the 43-kDa USF were first characterized, but only partial clones for the human 44-kDa USF (USF2, or FIP) have been reported. Here we describe a complete cDNA for the 44-kDa USF from murine cells. Analysis of this clone has revealed that the various USF family members are quite divergent in their N-terminal amino acid sequences, while a high degree of conservation characterizes their dimerization and DNA-binding domains. Interestingly, the 3' noncoding region of the 44-kDa USF cDNAs displayed an unusual degree of conservation between human and mouse. In vitro transcription/translation experiments indicated a possible role for this region in translation regulation. Alternative splicing forms of the 44-kDa USF messages exist in both mouse and human. Examination of the tissue and cell-type distribution of USF by Northern blot and gel retardation assays revealed that while expression of both the 43- and 44-kDa USF species is ubiquitous, different ratios of USF homo- and heterodimers are found in different cells.

Synthetic images by subspace transforms. I. Principal components images and related filters

The principal component (PC) approach offers compressions of an image sequence into fewer images and noise suppressing filters. Multiple MR images of the same tomographic slice obtained with different acquisition parameters (i.e., with different TR, TE, and flip angles), time sequences of images in nuclear medicine, and cardiac ultrasound image sequences are examples of such input image sets. In this paper noise relationships of original and linearly transformed image sequences in general, and specifically of original, PC, and PC-filtered images are discussed. As the spinoff, it introduces locally weighted PC transforms and filters, nonlinear PC's, and a single-image based filter for suppression of noise. Examples illustrate increased perceptibility of anatomical/functional structures in PC images and PC-filtered images, including extraction of physiological functional information by PC loading curves. Generally, the more correlated the original images are, the more effective is the PC approach.

Phase unwrapping through fringe-line detection in synthetic aperture radar interferometry

Interferometric synthetic aperture radar presents a new technology for performing high-resolution topographic mapping. One of the factors critical to mapping accuracy is phase unwrapping. This paper presents a new algorithm that unwraps phase through fringe-line detection. The algorithm is effective in preventing error propagation, it preserves the image resolution, and, in the mean time, it produces negligible local errors. An edge-segment linking approach and a curve-fitting approach are investigated, and their performances are compared. Test results of the algorithm are shown with the actual interferometric SEASAT synthetic aperture radar images over large-relief terrain near Yellowstone National Park with a short baseline, and results are shown over relatively flat terrain in Death Valley of California with a long baseline.

Transformation of pulsed nonideal beams in a four-dimension domain

A tensor method is presented to treat the transformation of pulsed nonideal beams in a four-dimension spatiotemporal domain. The equivalent beamwidth, mean pulse duration, divergence, spectrum width, radius of curvature, and pulsed beam quality factor for arbitrary-amplitude profile pulsed beams are introduced. The transformation rules of these parameters are derived by means of the four-dimension Huygens integral.

Volatile N-nitrosamines in salted fish samples from high- and low-risk areas for NPC in China

Four carcinogenic volatile nitrosamines (N-dimethylnitrosamine, NDMA; N-diethylnitrosamine, NDEA; N-nitrosopyrroline, NPYR; and N-nirosopiperilidine, NPIP) were screened in twenty specimens of salted fish collected from areas in China with different nasopharyngeal carcinoma (NPC) mortality rates. The highest NDMA, NDEA and total N-nitrosamine contents (322.92, 50.27 and 373.19 micrograms/kg, respectively) were found in the samples from Sihui, one of the areas with highest NPC mortality. The lowest contents (12.64, 7.65 and 20.29 micrograms/kg, respectively) were seen in the samples from Shanghai, the area with the lowest mortality from NPC in the study. These results confirm that there are appreciable levels of nitrosamines in the salted fishes consumed by residents in high-risk areas of NPC in China.

[Relation among syndrome of spleen deficiency and stagnation of liver-qi and electrogastrogram, gastric mucosal pathology and pulse-cardiovascular function in chronic gastric diseases]

In this research, Syndrome of Deficiency of Spleen (DS) and Stagnation of Liver-Qi (SLQ) as well as observations of electrogastrogram (EGG), gastric mucosal pathology and pulse cardiovascular examination were investigated in 56 cases of chronic gastric diseases (CGD). The results showed: (1) In SLQ with DS the amplitude of EGG was significantly higher than that of the control group (P < 0.01), it often indicated the active period of pathologic change, but in DS with SLQ, the amplitude of EGG was significantly lower than that of the control group (P < 0.01), it frequently denoted the static period. In case that DS equalled to SLQ, the amplitude of EGG was significantly higher than that of the control group (P < 0.01). It revealed that there were no significant difference between the patient's number of static and active periods (P > 0.05). It is valuable in Syndrome Differentiation of Deficiency and Excess and analysis of Superficiality and Origin in CGD. (2) Cardiovascular function was also affected in Syndrome differentiation of DS and SLQ. DS with SLQ manifested itself as reduction of left ventricle pump and declination for metabolism of microcirculation, they had significant difference as compared with the control group (P < 0.05), while SLQ with DS or equality between DS and SLQ had the normal function of left ventricle pump and metabolism of microcirculation, even though cardiac output were higher than that of control group (P < 0.05). It showed that the traditional Chinese medicine theory of interrelation among Heart and Spleen, Liver had their own hemodynamic bases.

Members of the USF family of helix-loop-helix proteins bind DNA as homo- as well as heterodimers

We have isolated human cDNA clones for USF2, a new member of the upstream stimulatory factor (USF) family of transcription factors. Analysis of these clones revealed the existence of highly conserved elements in the C terminal region of all USF proteins. These include the basic region, helix-loop-helix (HLH) motif, and, in the case of the human proteins, the C-terminal leucine repeat (LR). In addition, a highly conserved USF-specific domain is located immediately upstream of the basic region. Using in vitro translated proteins, we found that all members of the USF family bound DNA as dimers. The N-terminal portion of USF, including the USF-specific domain, was entirely dispensable for dimer formation and DNA-binding. However, deletion mutants of USF2 lacking the LR were deficient in DNA-binding activity. Interestingly, each of the USF proteins could form functional heterodimers with the other family members, including the sea urchin USF, which does not have a LR motif. This indicates that the conserved LR in human USF is not required for dimer formation, and influences only indirectly DNA-binding.

[Propagation methods for nutmeg seeds]

The test was conducted on the interrelated factors of germination of Nutmeg seeds. The result indicated that germination occurred fast and exuberantly (up to 88.8%) when the fresh and plump seeds (collected in summer or early autumn) were shown and expedited in clean sand in the complete shade during May-August after being treated with wet sand for 96 hours.

Rostral medullary cholinergic mechanisms and chronic stress-induced hypertension

This work was designed to study the relationship between the cholinergic mechanisms in the rostral ventrolateral medulla (rVLM) and the incidence of hypertension induced by chronic stress. Under anaesthetized conditions, bilateral microinjection of scopolamine (1.18 nmol/site) into the rVLM produced a much greater depressor response in chronic stress-induced hypertensive rats than in normotensive rats. Similar bradycardic effects were observed in both the normotensive and the hypertensive rats when scopolamine was injected into the rVLM. Acetylcholine (Ach) content and choline acetyltransferase (ChAT) activity in rostral medulla were determined by radioimmunoassay both in the normotensive and the hypertensive rats. Ach content and ChAT activity increased significantly in the hypertensive rats, and such increase mainly occurred within the ventral part of the rostral medulla. These results suggest that the cholinergic mechanisms in the rVLM may be activated during chronic stress and such activation may be involved in the pathogenesis of the hypertension induced by chronic stress.

Expression of phenylalanine ammonia-lyase gene during tracheary-element differentiation from cultured mesophyll cells ofZinnia elegans L

Expression of the phenylalanine ammonialyase (PAL) gene during tracheary-element differentiation was studied in mesophyll cell-suspension cultures ofZinnia elegans. Dose-response curves of benzyladenine (BA) and α-naphthaleneacetic acid (NAA) were obtained for the cultures in order to achieve the highest percentage of differentiation. The optimal concentrations of BA and NAA were 0.1 mg·l(-1) and 0.06 mg·l(-1), respectively, which normally stimulated about 40% differentiation by 96 h of culture. The effects of the same ratio but different amounts of BA and NAA on tracheary-element formation have been tested and the results indicate that the absolute amounts of BA and NAA rather than the ratio of them were important for tracheary-element formation in theZinnia cultures. The cells when cultured in the presence of 0.001 mg·l(-1) of BA and 0.06 mg·l(-1) of NAA expanded and divided but did not differentiate. The level of PAL activity, synthesis of PAL protein and the level of PAL mRNA peaked during 72 to 96 h when lignin was actively deposited. This indicated that the PAL gene was temporally and preferentially expressed in association with the lignification during tracheary-element differentiation and thus it can be regarded as a molecular marker for the process.

Spinal cord substance P mediates carbachol-induced cardiovascular responses from the rostral ventrolateral medulla

Intrathecal (i.t.) infusion of substance P (SP) antagonist, (D-Pro2, D-Trp7,9)-substance P (20 micrograms), lowered blood pressure profoundly without any significant change of heart rate. The hypertensive and tachycardic responses elicited by microinjection of carbachol (25 ng/site) into the bilateral rostral ventrolateral medulla (rVLM) were blocked by i.t. infusion of SP antagonist. These data provided evidence that an excitatory cardiovascular effect induced by cholinergic system in rVLM may be mediated mainly by the SP receptors in spinal cord.

[Preliminary study of aging and the senility index in traditional Chinese medicine]

According to the senile theory of TCM and the experience of the old generation, the authors chose 14 items which could represent the body's senility level. These items were graded. The total grade of these items were named "Senility Index of TCM" (SITCM). The age calculated from the regression equation of SITCM and age were named "Age of TCM", and the authors tried to estimate the body's senility level with it. According to the correlation analysis: with the rising of SITCM, lipid peroxide and viscosity of blood increase, function of heart, lung, brain decline and ATPase of RBC reduce, etc.

[Rules for differentiating symptoms and signs of the heart-qi deficiency syndrome]

344 cases of Heart-Qi Deficiency Syndrome (HQDS) including 19 Kinds of disease were observed to explore the rule of differentiation of symptoms and signs for HQDS. The results showed that the common symptoms of HQDS were weakness, shortness of breath, and palpitation, etc. According to with or without complicated cardiovascular diseases, the patients were divided into two groups: group A with cardiovascular diseases, group B without that. In group A, the symptoms and signs of HQDS were the most frequent and early clinical manifestations, the associated symptoms and signs were blood stasis and attack of water-evil, etc. In group B, in whom often associated with nervous and emotional symptoms such as insomnia, dreamfulness, and amnesia, etc., which was due to the disturbance of emotional activities of heart. In order to avoid diagnostic confusion, the authors suggest that the HQDS patients with cardiovascular diseases would be diagnosed as HQDS; on the other hand, the HQDS patients without cardiovascular diseases would be diagnosed as disturbance of emotional activities of heart.

Cytogenetic characterization of 20 lymphoblastoid lines derived from human individuals differing in bleomycin sensitivity

Forty lymphoblastoid (lymphoid) lines were established from 42 volunteer blood donors, including healthy individuals and patients with head and neck carcinomas. Each peripheral blood sample was split into two portions, one for the establishment of a lymphoid line and the other for short-term culture, which was used to estimate bleomycin sensitivity by cytogenetic procedures. Twenty lymphoid lines were selected at random to compare bleomycin sensitivity with data obtained from short-term lymphocyte cultures. In each set, bleomycin sensitivity of lymphoid cells was similar to that of the lymphocytes. The lymphoid lines, which can be propagated for an unlimited supply of relatively homogeneous cellular material, will be useful for a variety of future investigations.