[Reconstructing the limb end defects with a free mini-flap, a report of 18 cases]

OBJECTIVE

Some operative procedures were introduced for repairing hand or foot defects using the free mini-flap from the finger or toe.

METHODS

Eighteen cases of finger tip or foot wound were treated with the free mini-flap and vessel anastomosis. The size of the flap was 2 cm x 1 cm to 6 cm x 4 cm and the length of the pedicle was 2 to 4 cm.

RESULTS

All the eighteen free mini-flaps survived and the results were satisfactory.

CONCLUSION

The method of the mini-flap is a good option for covering of thumb, finger or foot defects when a local or an island flap is not available.

Hepatoprotective effect of Apocynum venetum and its active constituents

The leaves of Apocynum venetum L. are used as a tea material in north China and Japan. A water extract (500 mg/kg/day, one week administration) of the leaves of A. venetum showed protective effects against carbon tetrachloride (CCl4, 30 microliters/mouse) or D-galactosamine (D-GalN, 700 mg/kg)/lipopolysaccharide (LPS, 20 micrograms/kg)-induced liver injury in mice. Tumor necrosis factor-alpha (TNF-alpha) secreted from LPS-stimulated macrophages is the most crucial mediator in the D-GalN/LPS-induced liver injury model. The extract had no significant inhibition on the increase of serum TNF-alpha (1169 +/- 132 pg/ml vs. 1595 +/- 314 pg/ml of control), but exhibited a complete inhibition at the concentration of 100 micrograms/ml on TNF-alpha (100 ng/ml)-induced cell death in D-GalN (0.5 mM)-sensitized mouse hepatocytes. Further activity-guided fractionation resulted in the isolation of fifteen flavonoids viz. (-)-epicatechin (1), (-)-epigallocatechin (2), isoquercetin (3), hyperin (4), (+)-catechin (5), (+)-gallocatechin (6), kaempferol-6'-O-acetate (7), isoquercetin-6'-O-acetate (8), catechin-[8,7-e]-4 alpha-(3,4-dihydroxpyhenyl)-dihydro-2(3H)-pyranone (9), apocynin B (10), apocynin A (11), cinchonain Ia (12), apocynin C (13), apocynin D (14) and quercetin (15). All the compounds showed inhibitory effects on TNF-alpha-induced cell death with different intensities. The flavonol glycosides 3, 4, 7 and 8 and the phenylpropanoid-substituted flavan-3-ols 11 and 12 showed potent inhibitory effects on TNF-alpha-induced cell death with IC50 values of 37.5, 14.5, 31.2, 55.1, 71.9 and 41.2 microM, respectively. In contrast, the clinically used 5 and its analogues 1, 2 and 6 showed apparent activity only at 80 microM. These flavonoids appeared to be the hepatoprotective principles of the leaves of A. venetum. The hepatoprotective effects exhibited by the extract and its constituents suggest a validation of the leaves as a tea material.

A new zinc ribbon gene (ZNRD1) is cloned from the human MHC class I region

Eleven unique cDNA fragments were identified from YAC B30H3, which spans 330 kb in the human major histocompatibility complex class I region. One fragment (CAT80) was mapped 80 kb telomeric to the HLA-A locus. Using this cDNA fragment as probe, Northern analysis reveals a ubiquitously expressed transcript of about 850 nt in all 16 tissues tested. Based on the cDNA fragment sequence, a full-length cDNA of 858 bp that contains an open reading frame of 378 bp was cloned. Within the putative polypeptide of 126 amino acids, two zinc-ribbon domains were identified: Cx2Cx15Cx2C at the N-terminal and Cx2Cx24Cx2C at the C-terminal. The C-terminal domain is well conserved throughout evolution, including archaea, yeast, Drosophila, nematodes, amphibians, and mammals. The conserved amino acid sequence, CxRCx6Yx3QxRSADEx2TxFxCx2C, is highly homologous to the yeast RNA polymerase A subunit 9 and transcription-associated proteins. Alignment with genomic DNA demonstrates that this gene spans 3.6 kb and consists of four exons and three introns. Cross-species Northern analysis reveals a mouse homolog of a similar size and with an expression profile similar to those of the human gene. We have named this gene ZNRD1 for zinc ribbon domain-containing 1 protein.

[Spectral studies on the mechanism of rare earth poly (vinyl chloride) thermal stabilizers]

Rare earth Poly (Vinyl Chloride) (PVC) thermal stabilizers are one kind of effective and non-toxic stabilizers developed recently. By photoacoustic (PA) spectra and FT-IR analysis, their excellent performance in PVC stabilization progress can be studied conveniently. Good color remaining ability of rare earth stabilizers can be shown clearly by PA spectra and compared with others easily. From the IR spectrum and process data, the extra stabilization ability of rare earth stabilizers may be attributed to their conformation transforming effect.

Cytokine response gene 6 induces p21 and regulates both cell growth and arrest

Cytokine response gene #6 (CR6), cloned from interleukin 2-stimulated T lymphocytes, is homologous to GADD45 and MyD118, genes which promote cell cycle arrest and apoptosis. To determine how this gene family could possibly mediate both cell survival/proliferation and cell cycle arrest/death, transfectants were generated so that the genes could be expressed ectopically, independently from their normal inducing agents. In cycling retinoblastoma protein-negative (pRb-) cells, ectopic CR6 expression blocked G2/M transition, but did not prevent G1/S transition so that endoreduplication resulted. By comparison, when CR6, GADD45, and MyD118 genes were expressed ectopically in proliferating pRb+ cells, either G1/S or G2/M transition was effectively blocked, so that there was no endoreduplication. Consistent with these findings, in proliferating pRb-cells, ectopic expression of CR6 promoted the expression of both G1 and G2/M cyclins. By comparison, in pRb+ cells, the expression of G1 cyclins was increased, while expression of the mitotic cyclins was decreased. However, in pRb+ cells, cyclin-dependent kinase activities associated with both G1 and G2/M cyclins were decreased. Moreover, ectopic expression of all three genes resulted in the expression of the CKI, p21, both in pRb- and pRb+ cells. The physiologic induction of CR6 expression by IL2 in quiescent normal human T cells occurs transiently in the first half of G1, coordinately with the expression of p21. Therefore, this gene family regulates G1 and G2, and promotes either cell growth or arrest by a common mechanism.

A preliminary study on the ocular blood flow (OBF) of Hong Kong Chinese

The Ocular Blood Flow (OBF) Tonometer is an objective instrument to measure the Pulsatile Ocular Blood Flow (POBF), Pulse Amplitude (PA) and Pulse Rate (PR). It also provides the minimum intraocular pressure (IOPmin) simultaneously. This preliminary study applied the OBF Tonometer on 74 Hong Kong Chinese. They had their POBF measured followed by the Goldmann Applanation Tonometer (GAT). The OBF tonometer overestimates the IOP slightly. The average POBF result was smaller (661.2 microliters/min) than the previous studies. The effect of myopia of our sample (mean spherical equivalent -4.27 D) could be one of the contributing factors. Other factors include age and racial difference. Twenty-two subjects had their POBF measured again by the same practitioner and different practitioner for the reproducibility variation assessments. The POBF, PA and IOPmin were found to be repeatable between sessions. The POBF "norm" in Hong Kong Chinese needs to be established from a larger sample size and from a comparison on an age and refraction matched Caucasian group.

Active-oxygen scavenging activity of traditional nourishing-tonic herbal medicines and active constituents of Rhodiola sacra

The active-oxygen scavenging activity of 70 traditional herbal medicines used in China and Japan as nourishing tonics were evaluated by electron spin resonance (ESR) technique, in order to evaluate their effectiveness for anti-aging and to search for new active-oxygen scavengers from natural resources. Most of the 70 herbal medicines showed scavenging activity with various intensities. Areca catechu (methanol extract), Dendrobium plicatile (methanol extract), Juglans regia (water extract), Paeonia lactiflora (methanol extract), Psychotria serpens (water and methanol extracts), Rhodiola sacra (water and methanol extracts) and Uncaria rhynchophylla (water extract) especially showed strong scavenging activity against superoxide anion radical (*O2-), while J. regia (water and methanol extracts), Morus alba (water extract) and Schisandra chinensis (water extract) revealed strong scavenging activity against hydroxyl radical (HO*). In addition, the active-oxygen scavenging activities of 19 compounds isolated from R. sacra were also examined, and hydroquinone (1), caffeic acid (3), protocatechuic acid (6), gallic acid (7), (-)-epigallocatechin 3-O-gallate (8), 3-O-galloylepigallocatechin-(4beta-->8)-epigallocatechin+ ++ 3-O-gallate (10), heterodendrin (17) and gallic acid 4-O-beta-D-glucopyranoside (19) were found to show mild or strong inhibitory activity against superoxide anion radical (*O2-), while 4-hydroxybenzoic acid (2), 3, 4-hydroxycinnamic acid (4), 6-8 and 19 inhibited hydroxyl radical (OH*). These active-oxygen scavengers may contribute, to different extents, to their anti-aging action.

CR6: A third member in the MyD118 and Gadd45 gene family which functions in negative growth control

MyD118 and Gadd45 are two related genes which encode for proteins that play important roles in negative growth control, including both growth suppression and apoptosis. A strategy was employed to clone new members of the MyD118 and Gadd45 family of genes. Based on alignment of the deduced amino acid sequences, one cDNA clone was found to encode for the murine homologue of human CR6, originally cloned as an IL-2 immediate-early response gene. The murine and human CR6 proteins were observed to be 97% identical, indicating that CR6 is an evolutionarily conserved protein. Analysis of CR6 expression during hematopoietic cell development associated with growth arrest and apoptotic cell death, upon exposure of hematopoietic cells to a variety of growth arrest and apoptotic stimuli, and in a variety of murine tissues, has revealed that CR6 expression differs significantly from the expression of the related MyD118 and Gadd45 genes. Nevertheless, CR6, like MyD118 and Gadd45, suppressed colony formation of human lung carcinoma H1299 cells. These data suggest that CR6 plays similar, but not identical, roles to MyD118 and Gadd45 in negative control of cell growth.

Antagonistic interplay between antimitotic and G1-S arresting agents observed in experimental combination therapy

Paclitaxel is a naturally occurring antimitotic agent that has been shown to stabilize microtubules, induce mitotic arrest, and ultimately induce apoptotic cell death. The favorable clinical activity of paclitaxel has prompted considerable interest in combining paclitaxel with numerous other antineoplastic agents. Our previous studies have suggested 5-fluorouracil (5-FU), an antineoplastic agent that usually arrests tumor cells at the G1-S phase of the cell cycle, in combination with paclitaxel significantly represses paclitaxel-induced mitotic arrest and apoptosis. In the present study, we have extended this investigation to include several other antimitotic agents (vinblastine, colchicine, and nocodazole) in various combination schedules with the G1-S arresting agents 5-FU and hydroxyurea (HU). We found 5-FU, as well as HU, could significantly interfere with the overall cytotoxicity as compared with treatment with antimitotic agents alone. It appeared that 5-FU or HU severely limited the antimitotic agents' cytotoxic effects on both mitotic arrest and apoptosis. No combination of a G1-S arresting agent with an antimitotic agent in any schedule produced an antitumor effect greater than that of the antimitotic agent alone. In addition, biochemical examination revealed that 5-FU and HU blocked the antimitotic agent-induced increase of p21WAF1/CIP1 protein levels, as well as prevented the hyperphosphorylation of the bcl-2 and c-raf-1 proteins. These findings suggest that careful considerations may be necessary when combining antineoplastic agents that exert their cytotoxic action at different phases of the cell cycle.

Graded and dynamic reflex summation of myelinated and unmyelinated rat aortic baroreceptors

Unmyelinated (C) and myelinated (A) baroreceptor (BR) axons are present in rat aortic depressor nerve (ADN). With graded ADN electrical activation and anodal conduction blockade, reflex responses in anesthetized rats were assessed as changes in mean arterial pressure (MAP) and heart rate (HR). We tested the hypothesis that C-type BR inputs are effective at low frequencies because they outnumber A-type. Anodal current (Ian) reversibly eliminated all MAP and HR responses to A-selective stimuli. High intensities activated all ADN axons (A+C) and decreased MAP at lower frequencies (<10 Hz) than were effective with A-selective stimulation. I(an) reduced only MAP responses to >10-Hz ADN stimulation. Burst patterns significantly augmented A- but not C-selective reflex responses despite identical numbers of shocks per second. A-selective stimuli failed to evoke significant bradycardia even at 200 Hz. Maximum intensity stimuli plus Ian (C selective) evoked less bradycardia than without I(an) (A+C), indicating supra-additive summation unlike the occlusive summation for MAP responses. However, activation of reduced numbers of C-type BRs with all A-type BRs suggests a strong A to C interaction in reflex bradycardia responses. Surprisingly, Ian block of A-type conduction eliminated all reflex bradycardia at such submaximal intensities despite C conduction and depressor responses. A- and C-type BRs act synergistically, and A-type activity is absolutely required in cardiac but not in depressor pathways. Thus greater numbers do not appear to account for C-type BR efficacy, and critical interactions between these two sensory subtypes appear to occur differentially across cardiac and systemic baroreflex effector pathways.

Integration of NPY, AGRP, and melanocortin signals in the hypothalamic paraventricular nucleus: evidence of a cellular basis for the adipostat

Energy stores are held relatively constant in many mammals. The circuitry necessary for maintaining energy homeostasis should (1) sense the amount of energy stored in adipose tissue, (2) sense and integrate the multiple opposing signals regarding nutritional state, and (3) provide output regulating energy intake and expenditure to maintain energy homeostasis. We demonstrate that individual neurons within the paraventricular nucleus of the hypothalamus (PVH) are capable of detection and integration of orexigenic (neuropeptide Y [NPY]) and anorexigenic (melanocortin) signals, that NPY and melanocortins are functional antagonists of each other within the PVH in the regulation of feeding behavior, and that melanocortin administration within the PVH regulates both feeding behavior and energy expenditure. These data provide a cellular basis for the adipostat within neurons in the PVH that appear to be jointly regulated by NPY- and melanocortin-responsive neurons.

[The etiology of impotence in 327 diabetic male adults]

OBJECTIVE

To investigate the etiology of impotence in diabetic male adults.

METHODS

327 diabetic men aged 20 - 70 years were interviewed; 129 (39.6%) of them complained of impotence. All the 129 patients were initially evaluated by diabetologists and then underwent psychosexual assessment by psychiatrists. In addition, evaluation for retinopathy, neuropathy, vascular disease and sex hormone level was carried out.

RESULTS

The 327 diabetic patients were divided into four age ranges 25 - 34, 35 - 44, 45 - 54, and 55 - 70. The frequency of diabetic impotence in these groups was 9.7%, 34.2%, 48.0%, 62.7% respectively. Neuropathy was found in 79 (61.2%), psychogenic factor contributed in 66 (51.2%), vascular factor was present in 31 (24.0%), leakage of penile venous cavernosa occurred in 5 (3.9%), and treatment with impotence- related medications was the contributing factor in 2 (1.6%). There are significant differences of glycosylated hemoglobin, peripheral neuropathy, autonomic neuropathy, and proliferative retinopathy between impotent and potent diabetic patients. The degree of psychological problem is more serious in the diabetic impotent patients than in potent patients according to Minnesota multiphasic personality inventory (MMPI) test. No significant difference was found in smoking, alcohol and plasma testosterone level.

CONCLUSION

The etiology of diabetic impotence is multifactorial. Neuropathy is the main cause, but vascular and psychological factors also contribute to it significantly.

Screening of crude drug extracts for prolyl endopeptidase inhibitory activity

Prolyl endopeptidase (PEP, EC 3.4.21.26) is an enzyme to play a role in metabolism of proline-containing neuropeptides, such as vasopressin, substance P and thyrotropin-releasing hormone (TRH), which were suggested to be involved with learning and memory processes. Then, specific inhibitor of PEP is expected to have antiamnesic effects, and thus we screened forty-six water- and methanol-extracts from crude drugs selected on the basis of traditional Chinese medicine theory, for Flavobacterium prolyl endopeptidase inhibition. Among them, the water-extracts of Rhodiola sacra (IC50, 0.77 microgram/ml) and the methanol-extracts of Lycopodium clavatum (IC50, 1.3 micrograms/ml), Paeonia lactiflora var. trichocarpa (IC50, 5.7 micrograms/ml), Paeonia veitchii (IC50, 2.4 micrograms/ml) and Rhodiola sacra (IC50, 0.67 microgram/ml) showed strong inhibitory activity. In addition, we also examined the PEP inhibitory activity of eleven compounds from Salvia deserta, and found that in addition to a catechol group alpha-hydroxy-para-quinone group may be related to the PEP inhibition.

Possible mechanisms of paclitaxel-induced apoptosis

Paclitaxel, a naturally occurring antimicrotubule agent, has been demonstrated to possess significant cell-killing activity in a variety of tumor cells through induction of apoptosis. It is currently unclear whether this finding suggests a novel mechanism of action for paclitaxel against tumor cells or just represents an end product of the well-known action of paclitaxel on microtubules and cell cycle arrest. Morphologically, a sustained block of mitosis seems to be required for paclitaxel-induced apoptosis because most apoptotic events are observed to occur in cells showing a prior mitotic arrest. However, this morphological correlation alone does not prove that paclitaxel-induced apoptosis is indeed a secondary event resulting from mitotic arrest. Instead, several lines of evidence obtained from recent studies have suggested that apoptotic cell death induced by paclitaxel may occur via a signaling pathway independent of microtubules and G2/M arrest.

Interaction of NPR1 with basic leucine zipper protein transcription factors that bind sequences required for salicylic acid induction of the PR-1 gene

The Arabidopsis thaliana NPR1 has been shown to be a key regulator of gene expression during the onset of a plant disease-resistance response known as systemic acquired resistance. The npr1 mutant plants fail to respond to systemic acquired resistance-inducing signals such as salicylic acid (SA), or express SA-induced pathogenesis-related (PR) genes. Using NPR1 as bait in a yeast two-hybrid screen, we identified a subclass of transcription factors in the basic leucine zipper protein family (AHBP-1b and TGA6) and showed that they interact specifically in yeast and in vitro with NPR1. Point mutations that abolish the NPR1 function in A. thaliana also impair the interactions between NPR1 and the transcription factors in the yeast two-hybrid assay. Furthermore, a gel mobility shift assay showed that the purified transcription factor protein, AHBP-1b, binds specifically to an SA-responsive promoter element of the A. thaliana PR-1 gene. These data suggest that NPR1 may regulate PR-1 gene expression by interacting with a subclass of basic leucine zipper protein transcription factors.

A MHC-encoded ubiquitin-like protein (FAT10) binds noncovalently to the spindle assembly checkpoint protein MAD2

Recently a number of nonclass I genes were discovered in the human MHC class I region. One of these, FAT10, encodes a protein consisting of two domains with homology to ubiquitin. FAT10 mRNA is expressed constitutively in some lymphoblastoid lines and dendritic cells and in certain other cells after gamma-interferon induction. FAT10 protein expression is controlled at several levels including transcription, translation, and protein stability. Yeast two-hybrid screening of a human lymphocyte library and immunoprecipitation studies revealed that FAT10 noncovalently associated with MAD2, a protein implicated in a cell-cycle checkpoint for spindle assembly during anaphase. Thus, FAT10 may modulate cell growth during B cell or dendritic cell development and activation.

[The significance of inflammatory markers in sputum of asthmatic and chronic obstructive pulmonary diseases patients before and after glucocorticoid treatment]

OBJECTIVE

To study the change of cytokines and eosinophil cationic protein (ECP) level in the sputum before and after glucocorticoid (GC) inhalation treatment so as to comprehend their effect on asthmatic and chronic obstructive pulmonary diseases (COPD) patients.

METHODS

A method to induce sputum with inhaled hypertonic saline was used. The level of interleukin (IL)-5, IL-8 and ECP was measured with enzyme-linked immunosorbent assay method.

RESULTS

The concentration of ECP decreased from (500.3 +/- 49.6) microg/L to (59.8 +/- 10.9) microg/L, the percentage of eosinophils (Eos) dropped from (11.6 +/- 1.7) x 10(-2) to (4.1 +/- 0.7) x 10(-2) and there is significant difference in the concentration of IL-5 in the group of asthmatic patients after GC treatment. However, the concentration of IL-5 in the COPD patients did not show significant change after the same therapy.

CONCLUSION

Respiratory tract inflammation in asthma is related to Eos activation and increase in ECP and IL-5 excretion, while respiratory tract inflammation in COPD is related to neutrophil increase. These changes can be considered as the indicator of airway inflammation in asthma or COPD. Through regulating the quantity and function of the inflammatory cells and inhibiting the formation of cytokines to control the asthmatic airway inflammation, GC inhalation treatment will have better effect in treating asthmatic patients than COPD patients.

Mitotic chromosomal bcl-2. II. Localization to interphase nuclei

We have previously shown, by immunofluorescence of fixed cells, that bcl-2 is found only in mitotic chromosomes in KB cultured human tumor cells expressing low levels of this oncoprotein. However, other studies showed that bcl-2 did not change its levels during the cell cycle when analyzed using Western blots. In this study we analyzed the distribution of bcl-2 during interphase, the point at which it is undetectable by immunofluorescence, using biochemical extraction, immunoprecipitation, and cell fractionation with Western blots. Interestingly, when carefully examined by immunofluorescence in fixed cells, the earliest point in the cell cycle showing bcl-2 localization was early G2, in which bcl-2 could be found within the intact nucleus. In spite of showing no immunofluorescence reaction in fixed interphase cells, immunoprecipitation of gentle detergent extracts showed that bcl-2 from interphase cells reacted readily with the antibody used (#124) after extraction. However, immunoprecipitation using anti-bcl-2 followed by Western blots using anti-Bax showed that, unlike overexpressing cells, this bcl-2 was not complexed with Bax. Classical cell fractionation methods were used to separate nuclei from cytosol and cell membranes. Surprisingly, these experiments clearly showed that essentially all of the bcl-2 in interphase KB cells was present in the nucleus. Therefore, the lack of reaction in fixed cells with anti-bcl-2 antibody reflects either a masking or a conformational change of the reactive epitope in bcl-2 present within the nucleus. By correlation, this change may be related to the phosphorylation of bcl-2 that occurs just before mitosis. The nature of this novel yet highly conserved nuclear form of bcl-2 and the understanding of its function will require further study.

Prolyl endopeptidase inhibitors from the underground part of Rhodiola sacra S. H. Fu

Prolyl endopeptidase (PEP, EC 3.4.21.26) is an enzyme which plays a role in the metabolism of proline-containing neuropeptides, e.g., vasopressin, substance P and thyrotropin-releasing hormone (TRH), which have been suggested to be involved in learning and memory processes. In our systematic screening for PEP inhibitors from traditional Chinese medicines, we found that MeOH extract from the underground part of Rhodiola sacra S. H. Fu shows significant inhibitory activity against PEP from Flavobacterium meningosepticum. Examination of the constituents of the extract resulted in the isolation of nineteen known compounds, identified as hydroquinone (1), 4-hydroxybenzoic acid (2), caffeic acid (3), 4-hydroxycinnamic acid (4), suberic acid (5), protocatechuic acid (6), gallic acid (7), (-)-epigallocatechin 3-O-gallate (8), 2-phenylethyl beta-D-glucopyranoside (9), 3-O-galloylepigallocatechin-(4beta-->8)-epigallocatechin+ ++ 3-O-gallate (10), 2-phenylethyl alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside (11), sacranoside A (12), beta-D-glucopyranosyl 4-hydroxybenzoate (13), rhodiocyanoside A (14), rhodiooctanoside (15), sarmentosin (16), heterodendrin (17), arbutin (18) and 4-O-(beta-D-glucopyranosyl)-gallic acid (19). Among these, 1, 2, 5, 8-10, 13, 16, 18 and 19 have been isolated for the first time from R. sacra, among which 5, 9, 10, 13, 16, 18 and 19 have been isolated from Rhodiola plants for the first time. On the PEP inhibition, seven compounds (6-8, 10, 12, 18, 19) showed inhibition with an 1C50 of 27.8, 487, 1.47, 0.437, 348, 391 and 215 microM, respectively. The kinetic study of these inhibitors indicated that they are noncompetitive inhibitors, except for 6 which is a competitive inhibitor.

[The CT scan of the agger cell and its adjacent structure in endoscopic paranasal sinus surgery]

OBJECTIVE

To promote the development of endoscopic frontal sinus surgery and naso-lacrimal anastomosis surgery by studying the agger cells and their adjacent structures.

METHODS

One hundred patients were observed by the continuous coronal CT scan and sagittal CT scan of the paranasal sinuses. Among them, 30 had deviation of nasal septum; 40 had chronic nasosinusitis. There were 80 adult and 20 children.

RESULTS

(1) The agger cells existed in 99% of the cases, the development of the agger cells in 9-16 years old children, and adult had no difference; (2) The morphology of agger cells differed widely, but its relationship to the anterior border of the middle nasal concha, bulla ethmoidalis and nasolacrimal canal was quite stable; (3) The upward pneumatization of the agger cells was not related to deviation of nasal septum, but closely related to the development of the frontal sinus; (4) The anterior nasosinusitis often influenced the agger cells and might result in hyperosteogeny.

CONCLUSION

The agger cells situated at the pathway of the intranasal frontal sinus during surgery and dacryocystorhinostomy, the nasal CT scan might be beneficial to the prevention of surgical complications.

Mitotic chromosomal bcl-2. I. Stable expression throughout the cell cycle and association with isolated chromosomes

Bcl-2 is present in a cytoplasmic distribution in cells that express high levels of this oncoprotein. In contrast, using immunocytochemistry in cells expressing low levels of bcl-2, such as KB human carcinoma cells, we and others have shown that bcl-2 is present on the surface of mitotic chromosomes. However, monoclonal antibodies reactive with an epitope representing amino acids 41-54 of the bcl-2 sequence did not detect bcl-2 in other phases of the cell cycle. This study extended those earlier findings to determine if bcl-2 was expressed as a cyclin or if this pattern was an artifact of immunocytochemistry. Immunofluorescence studies in several other human cell lines showed the same mitotic distribution of bcl-2. Other studies using flow cytometry also showed selective mitotic phase detection of bcl-2. A comparison of available commercial antibodies showed that, in spite of reactivity with denatured bcl-2 on Western blots, clear reactivity with bcl-2 in fixed cells was found only with those reactive with the (a.a. 41-54) epitope. With RNase protection and Western blot analyses, cells synchronized at various stages of the cell cycle showed constant levels of bcl-2 mRNA and protein. Analysis of bcl-2 using Western blots showed a band with the same apparent molecular weight as that seen in comparison with authentic bcl-2 overexpressed in the cytoplasm. The retention of bcl-2 on chromosomes in unfixed, permeabilized preparations was influenced by protease treatment, phosphate, and pH. Studies using isolated chromosomes showed that much of the bcl-2 in these cells was attached to chromosomes in mitosis, had the expected molecular weight, and was phosphorylated in the same manner as that seen in whole-cell extracts. These results show that bcl-2 is not a cyclin and that the bcl-2 localized on chromosomes is the same molecule seen by immunoblotting. These results suggest that the reactive (a.a. 41-54) epitope present in bcl-2 is somehow modified or masked in interphase.

Changing pattern of heart diseases in Shanghai from the 1950s to 1980s

OBJECTIVE

To determine the pattern of dynamic change in types of heart diseases in the past 4 decades for providing a reference to treatment and prevention of heart diseases in China.

METHODS

All adult cardiac patients admitted to the Zhong Shan Hospital and Hua Shan Hospital from 1948 to 1989 were analyzed. The constituent ratio of different heart diseases in the 1950s, 1960s, 1970s and 1980s was compared.

RESULTS

The percentage of heart diseases among medical inpatients increased in each of the recent 4 decades, from 9.89%, 15.69%, 20.90% to 23.54% respectively. The constituent ratio of different heart diseases changed, coronary heart disease constituted the highest proportion, next came rheumatic heart disease, and congenital heart disease was in third place. Congenital heart disease, myocarditis, cardiac dysrhythmia without organic heart disease, cardiomyopathy and endocarditis increased, rheumatic heart disease, pulmonary heart disease and hypertensive heart disease apparently decreased; syphilitic heart disease could rarely be encountered.

CONCLUSION

China is now facing a low overall death rate, a long life expectancy and an aging population. The incidence of heart diseases increased gradually and patterns of heart diseases kept changing. The overall trend is that heart diseases which were not related to infection are increasing while heart diseases related to bacterial infection are decreasing.

[Expression of P62c-myc protein in breast cancer and its clinical significance]

The objective of this study was to determine the clinical significance of P62c-myc protein expression in breast cancer. P62c-myc protein was detected in 107 patients with breast cancer by immunohistochemical techniques (LSAB). The results showed that the positive rate of P62c-myc protein expression was 63.55% (68/107). The overexpression of P62c-myc protein related negatively with survival. 94.00% of the cases with overexpression of P62c-myc protein survived < or = 5 years, 65.00% survived > 5 years-< 10 years, and 21.62% survived > or = 10 years. There were significant associations of P62c-myc expression with advance clinical stage, high histological grade, and positive axillary node status in breast cancers. All of these findings suggested that overexpression of P62c-myc might be an important prognostic factor, and the detection of P62c-myc protein might be arranged as a regular pathological examination in the cases of breast cancer.

Characterization of the human neurocan gene, CSPG3

Neurocan is a chondroitin sulfate proteoglycan thought to be involved in the modulation of cell adhesion and migration. Its sequence has been determined previously in rat and mouse (Rauch et al., 1992. Cloning and primary structure of neurocan, a developmentally regulated, aggregating, chondroitin sulfate proteoglycan of the brain. J. Biol. Chem. 267, 19536-19547; Rauch et al., 1995. Structure and chromosomal location of the mouse neurocan gene. Genomics 28, 405-410). We describe here the complete coding sequence of the human neurocan mRNA, known as CSPG3, as well as mapping data, expression analysis, and genomic structure. A cDNA known as CP-1 was initially sequenced as part of a gene discovery project focused on characterizing chromosome 19-specific cDNAs. Sequence homology searches indicated close homology to the mouse and rat proteoglycan, neurocan (GenBank accession Nos X84727 and M97161). Northern analysis identified a brain-specific transcript of approx. 7.5kb. A longer cDNA clone, GT-5, was obtained, fine-mapped to the physical map of chromosome 19 by hybridization to a chromosome-specific cosmid library, and sequenced. Full coding sequence of the mRNA indicates a 3963bp open reading frame corresponding to a 1321 amino acid protein, similar to the protein length found in mouse and rat. The amino acid sequence of human neurocan shows 63% identity with both the mouse and rat sequences. Finally, genomic sequencing of a cosmid containing the complete neurocan gene was performed to determine the genomic structure of the gene, which spans approx. 41kb, and is transcribed in the telomere to centromere orientation.

Mahogany (mg) stimulates feeding and increases basal metabolic rate independent of its suppression of agouti

The mahogany (mg) locus originally was identified as a recessive suppressor of agouti, a locus encoding a skin peptide that modifies coat color by antagonizing the melanocyte-stimulating hormone receptor or MC1-R. Certain dominant alleles of agouti cause an obesity syndrome when ectopic expression of the peptide aberrantly antagonizes the MC4-R, a related melanocyte-stimulating hormone receptor expressed in hypothalamic circuitry and involved in the regulation of feeding behavior and metabolism. Recent work has demonstrated that mg, when homozygous, blocks not only the ability of agouti to induce a yellow coat color when expressed in the skin of the lethal yellow mouse (AY), but also the obesity resulting from ectopic expression of agouti in the brain. Detailed analysis of mg/mg AY/a animals, presented here, demonstrates that mg/mg blocks the obesity, hyperinsulinemia, and increased linear growth induced by ectopic expression of the agouti peptide. Remarkably, however, mg/mg did not reduce hyperphagia in the AY/a mouse. Furthermore, mg/mg induced hyperphagia and an increase in basal metabolic rate in the C57BL/6J mouse in the absence of AY. Consequently, although mahogany is broadly required for agouti peptide action, it also appears to be involved in the control of metabolic rate and feeding behavior independent of its suppression of agouti.

[Studies on flavonoids from Fenugreek (Trigonella foenumgraecum L.)]

OBJECTIVE

To study the flavonoids in fenugreek (Trigonella foenumgraecum) produced in China.

METHOD

The flavonoids were isolated with silica gel, polyamide and Sephadex LH-20 chromatography, and their structures were identified by physical, chemical properties and spectral analysis.

RESULT

Five flavonoid compounds were isolated from fenugreek seeds and identified as vitexin, tricin, naringenin, quercetin and tricin-7-O-beta-D-glucopyranoside.

CONCLUSION

Three flavonoids, tricin, naringenin and tricin-7-O-beta-D-glucopyranoside, were isolated from fenugreek as well as from the plants of Trigonella for the first time.

In vitro evaluation of combination chemotherapy against human tumor cells (Review)

Combination therapy with multiple drugs or with multiple modalities is common practice in the treatment of cancer. The purpose of using drugs in combinations is to increase the therapeutic efficacy, decrease toxicity toward the host and minimize or delay the development of drug resistance. Presently used clinical protocols for cancer combination therapy are mainly obtained empirically or from clinical trials. Accumulation of experience from clinical trials is invaluable but is a slow and expensive process. Also, due to heterogeneous patient populations exposed to different environments, human clinical data frequently cannot be used for quantitative synergy determinations. Therefore, in vitro quantitative drug combination studies with cultured tumor cells are becoming imperative either as prospective studies or as adjuvant assessment for combination therapy. In recent years, a variety of in vitro assays have been developed to examine cytotoxicity or biochemical effects of drugs on cultured tumor cells. These methods can, not only quickly predict the potential therapeutic effects of the combined agents, but also provide the information or clues to the possible mechanisms of drug interactions. In addition, with the better understanding of various antineoplastic drugs and the development of new technologies to characterize actions of the drugs, the in vitro study of combination therapy is no longer limited to the measurement of cytotoxic effects. Instead, many other studies, such as cell cycle analyses, detection of apoptosis and biochemical analyses of drug interactions have also become common methods for the in vitro evaluation of combination drug therapy.

Contribution of protein charge to partitioning in aqueous two-phase systems

Protein partitioning in aqueous two-phase systems based on phase-forming polymers is strongly affected by the net charge of the protein, but a thermodynamic description of the charge effects has been hindered by conflicting results. Many of the difficulties could be because of problems in isolating electrochemical effects from other interactions of phase components. We explored charge effects on protein partitioning in poly(ethylene glycol)-dextran two-phase systems by using two series of genetically engineered charge modifications of bacteriophage T4 lysozyme produced in Escherichia coli. The two series, one in the form of charged-fusion tails and the other in the form of charge-change point mutations, provided matching net charges but very different polarity. Partition coefficients of both series were obtained and interfacial potential differences of the phase systems were measured. Multi-angle laser light scattering measurements were also performed to determine second virial coefficients. A semi-empirical model accounting for the roles of both charge and non-charge effects on protein partitioning behavior is proposed, and the results predicted from the model are compared to the results from the experiments.

Synthesis and pharmacological evaluation of N,N'-diarylguanidines as potent sodium channel blockers and anticonvulsant agents

Synthesis and structure-activity relationships (SAR) are described for a series of N,N'-diarylguanidines related to N-acenaphth-5-yl-N'-(4-methoxynaphth-1-yl)guanidine (3) as anticonvulsants through blockade of sodium channels. SAR studies on compound 3 led to several simpler diphenylguanidines with improved in vitro and in vivo activity. Compounds were screened for blockade of sodium channels in a veratridine-induced [14C]guanidinium influx assay (type IIA sodium channels) and for anticonvulsant activity in the audiogenic DBA/2 mouse model. Results indicated that N, N'-diphenylguanidines substituted with flexible and moderate size lipophilic groups were preferred over aryl and/or hydrophilic groups for biological activity. Among the compounds studied, n-butyl- and/or n-butoxy-containing guanidines showed superior biological activity. A possible relationship between in vitro and in vivo activity of this compound series and their measured/calculated lipophilicities was investigated. Compounds of this series showed only weak NMDA ion channel-blocking activity indicating that the anticonvulsant activity of these compounds is unlikely to be mediated by NMDA ion channels but, more likely, by acting at voltage-gated sodium channels.

[Experimental study on reducing effect of shexiang baoxin pill from damage of arterial wall caused by hyperlipemia]

OBJECTIVE

To study the protecting effect of Shexiang Baoxin Pill (SXBXP) on arterial wall in hyperlipemia rabbit model.

METHODS

Thirty-six male, New Zealand rabbits were randomized into three groups: control group, fed with common diet for 8 weeks: Hypercholesterolemia group (HC) and SXBXP group (SX), fed with 1% cholesterol and 3% lard diet for 8 weeks. In SX group, SXBXP was iven from 7th week for 2 weeks. The plasma levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) were measured at the first, 6th and the 8th week of experiment. Serum superoxide dismutase (SOD) and electrocardiography (ECG) were also evaluated at the 8th week. Light microscopy and transmission electron microscopy were adopted to assess the degree of pathologic damage of arterial wall.

RESULTS

SXBXP could reduce the levels of serum TC and LDL-C, as compared with the HC group, P < 0.05. It could also reduce the extent of atherosclerotic lesion and the severity of intimal proliferation.

CONCLUSION

SXBXP has the effect of inhibiting development of experimental atherosclerosis.

Identification of altered expression of ADP/ATP translocase during cellular senescence in vitro

In this study, we have used the mRNA differential display technique to investigate the changes in gene expression that occur in the process of cellular aging. A number of cDNAs whose corresponding mRNAs are either increasingly or decreasingly expressed in senescent cells were thereby isolated. Through DNA sequencing, one of these differentially displayed mRNAs was identified as mitochondrial ADP/ATP translocase. The altered expression of ADP/ATP translocase in different stages of senescent fibroblasts was further confirmed by Northern blots and semiquantitative RT-PCR. Our results demonstrate that expression of ADP/ATP translocase is progressively decreased during the process of in vitro cellular senescence. Further analyses with MTT assays indicate that the decreased expression of ADP/ATP translocase in senescent cells is in parallel with the decline of mitochondrial functions, suggesting that altered expression of this important mitochondrial enzyme might play an active role in the process of cellular senescence.

Differential frequency-dependent reflex integration of myelinated and nonmyelinated rat aortic baroreceptors

Electrical activation of myelinated (A type) and nonmyelinated (C type) baroreceptor axons (BR) in aortic depressor nerve (ADN) evoked baroreflex changes in mean arterial pressure (MAP) in chloralose-urethan-anesthetized rats. Low stimulation intensities (<3 V) activated only A-type BR electroneurograms (ENG). A-type selective stimulus trains required minimum frequencies >10 Hz to evoke reflex MAP decreases, and the largest MAP responses occurred at 50 Hz and higher. In contrast, high stimulation intensities (18-20 V) maximally activated two volleys in ADN ENG corresponding to A- and C-type BR volleys. High-intensity trains decreased MAP at low frequency (1 Hz) and largest reflex responses at >/=5 Hz. Capsaicin (Cap) applied periaxonally to ADN selectively blocked C-type ENG volleys but not A-type volleys. Reflex curves with supramaximal intensity during Cap were indistinguishable from the pre-Cap, low-intensity baroreflexes. In comparison, vagus ENG showed graded Cap block of the C-fiber volley (ED50 = 200 nM) without significant attenuation of the A-type volley below 1 microM. However, 100 microM Cap blocked conduction in all myelinated vagal axons as well as C-type axons. Thus Cap is selective for sensory C-type axons only at low micromolar concentrations. Myelinated and nonmyelinated arterial BR evoke characteristically different frequency-response reflex relations that suggest distinct differences in sensory information processing mechanisms.

[A molecular variant of angiotensinogen gene is associated with myocardial infarction in Chinese]

OBJECTIVE

A molecular variant of the angiotensinogen(AGT) gene with threonine instead of methionine at position 235(i.e.,with M235T polymor- phism) has been shown to be associated with essential hypertension, preeclampsia, coronary atherosclerosis, coronary heart disease(CHD), myocardial infarction(MI) in Caucasians and in Japanese. The purpose of the present study was to assess whether the M235T polymorphism was associated with MI in a Chinese population.

METHODS

M235T polymorphism in exon 2 of AGT gene was determined by polymerase chain reaction(PCR) and restriction endonuclease analysis in a study of 57 patients with MI and 76 non-CHD individuals as control.

RESULTS

The frequencies of T235 allele(0.82) and 235TT genotype (0.70) in the MI group were higher than those in the control subjects(0.63 and 0.42 respectively, P=0.013 and P<0.025). AGT gene 235TT genotype was at significantly increased risk of MI(odds ratio 3.65, P=0.016) in analysis adjusted for several main CHD risk factors.

CONCLUSION

There is a significant association between AGT gene 235TT genotype and MI, this genotype might be an independent risk for MI in Chinese population.

[Chinese Chlorella viruses and their molecular biological properties]

An extensive survey for Chlorella viruses revealed that Chlorella viruses are widely distributed over China. Eleven isolates of Chlorella viruses have been isolated, which lysis the Chlorella viruses sp. (strain NC64A). These isolates were named BJ-1, BJ-2, BJ-3, BJ-4, FJ-1, FJ-2, NJ-1, CDT-1, HCJ-1, SCB-1 and SCC-1 respectively. They have several common properties, including polyhedral morphology, and linear dsDNA genomes. However, the restriction patterns of viral DNA, the concentration of m5dC and m6dA in viral DNA, and the composition of viral structure protein are different among these isolates. All of viral major capsid proteins are 54,000 except FJ-1, whose major capsid protein is smaller than 54,000. Western blot analysis showed strong immunological cross reaction among all of viral proteins with PBCV-1's antiserum except FJ-1. It indicates that the homology between these isolates and PBCV-1 is high. Among these isolates, FJ-1 has some special properties.

[The role of lens epithelium in cataract formation in diabetic rats]

This study was designed to evaluate the changes and the role of lens epithelium in sugar cataract formation, in regard to the fact that the highest level of aldose reductase is found in this layer of lens. By light and electron microscopy, we examined the histological changes of central epithelium in lens of rats made diabetic with streptozotocin (STZ) with or without AL1576, an aldose reductase inhibitor, at varying periods of time ranging from 5 to 40 days after intraperitoneal injection of STZ. Also, we examined Na-K-ATPase activity in lens epithelium of rats with diabetes, diabetes plus AL1576 and normal controls at the time of 30 days. The results showed that the first detectable abnormalities occurred after 15 days of STZ injection and were limited to the lens epithelium; cell edema, intracellular vacuoles and extention of rough endoplasmic reticulum pool were remarkable; that AL1576 could prevent almost all of the lesion mentioned above; and that Na-K-ATPase activity in lens epithelium of rats with diabetes increased at the time of 30 days. The findings suggest that lens epithelium may play an important role in sugar cataractogenesis.

Effects of procainamide on wave-front dynamics during ventricular fibrillation in open-chest dogs

BACKGROUND

There is increasing evidence that both functional reentrant wave fronts and multiple wavelets are present during ventricular fibrillation (VF). However, the effects of procainamide on the characteristics of activation waves during VF are poorly understood.

METHODS AND RESULTS

Seven dogs were studied; six underwent subendocardial chemical ablation procedures. A plaque with 317 to 480 bipolar electrodes was sutured to the right ventricular free wall, and the patterns of activation were registered with a computerized mapping system. VF was electrically induced, and the patterns of activation were registered at baseline and during procainamide infusion (serum concentration, 9.3+/-1.9 microg/mL). Among the six dogs that had their subendocardium ablated, reentrant wave fronts were present in 6 of the 108 runs of VF at baseline and in 6 of the 100 runs of VF during procainamide infusion. By analyzing the wave fronts, we found that the cycle length, refractory period, conduction velocity, and wavelength at baseline were 101+/-9 ms, 54+/-5 ms, 0.93+/-0.21 mm/ms, and 51+/-16 mm, respectively, and during procainamide infusion, values became 125+/-11 ms (P<.001), 119+/-7 ms (P<.001), 0.42+/-0.02 mm/ms (P<.001), and 50+/-4 mm (P=.8), respectively. The vast majority of the activation waves do not form organized reentry. These activation waves broke up more frequently at baseline than during procainamide administration. The number of activation waves was 7.25+/-1.39 s(-1) x cm(-2) at baseline and 4.45+/-1.80 s(-1) x cm(-2) during procainamide administration (P<.001). The dog without subendocardial ablation had similar results.

CONCLUSIONS

Procainamide decreases the number of wavelets during VF by preventing spontaneous wave breaks. This represents a novel mechanism of antiarrhythmic drug action.

XRCC2 and XRCC3, new human Rad51-family members, promote chromosome stability and protect against DNA cross-links and other damages

The phenotypically similar hamster mutants irs1 and irs1SF exhibit high spontaneous chromosome instability and broad-spectrum mutagen sensitivity, including extreme sensitivity to DNA cross-linking agents. The human XRCC2 and XRCC3 genes, which functionally complement irs1 and irs1SF, respectively, were previously mapped in somatic cell hybrids. Characterization of these genes and sequence alignments reveal that XRCC2 and XRCC3 are members of an emerging family of Rad51-related proteins that likely participate in homologous recombination to maintain chromosome stability and repair DNA damage. XRCC3 is shown to interact directly with HsRad51, and like Rad55 and Rad57 in yeast, may cooperate with HsRad51 during recombinational repair. Analysis of the XRCC2 mutation in irs1 implies that XRCC2's function is not essential for viability in cultured hamster cells.

Isolation and characterization of RAD51C, a new human member of the RAD51 family of related genes

The yeast and human RAD51 genes encode strand-transfer proteins that are thought to be involved in both recombinational repair of DNA damage and meiotic recombination. In yeast, the Rad51 family of related proteins also includes Rad55, Rad57 and Dmc1. In mammalian cells, five genes in this family have been identified (HsRAD51, XRCC2, XRCC3, RAD51B/hREC2 and HsDMC1), and here we report the isolation of the sixth member, RAD51C. RAD51C was originally identified by a computer screen of the EST database. A full-length approximately 1.3 kb cDNA clone has been isolated that encodes a protein of 376 aa, having a 18-26% aa identity with other human Rad51 family members. RAD51C includes a previously mapped sequenced-tagged site location near the end of chromosome 17q. The RAD51C transcript is expressed in various human tissues, with highest level of expression in testis, followed by heart muscle, spleen and prostate. Yeast two-hybrid experiments indicate that the Rad51C protein binds to two other members of the Rad51 protein family (Xrcc3 and Rad51B) but not to itself. These findings suggest that Rad51C may function similarly to the yeast Rad55 or Rad57 proteins, rather than as a Rad51 functional homolog.

[Effect of up-regulation of S-AdoMet synthetase on taxol-induced apoptosis in human breast cancer cells]

OBJECTIVE

To investigate the gene regulation of taxol-induced apoptosis.

METHODS

Northern blot hybridization, enzyme activity assay of S-AdoMet synthetase and flow cytometry were performed in the investigation of expression in the mRNA level and biological action of S-AdoMet synthetase in taxol-induced apoptosis in human breast cancer cell line (BCap 37).

RESULTS

Up-regulation of S-AdoMet synthetase expression was resulted by taxol treatment and the expression peaked at 48 hours. Moreover, the up-regulation of S-AdoMet synthetase was associated with cytotoxicity of antimicrotubule agents including taxol and colchicine. Inhibition rate of S-AdoMet synthetase activity by 1% DMSO was 34% in taxol-treated cells and 14% in taxol-untreated cells compared to control groups, respectively. Posttreatment with 1% DMSO following pretreatment with individual antitumor agent for 3 hr promoted apoptotic cell death of taxol-, colchicine-, and adriamycin-treated BCap37 cells.

CONCLUSION

The induction of apoptosis enhanced by post-treatment with DMSO in taxol-treated cells is probably linked to its inhibition on enzyme activity of S-AdoMet synthetase, suggesting that the increased expression of S-AdoMet synthetase possibly plays an important role in protecting cells from DNA fragmentation in taxol-induced apoptosis.

Identification of a novel human RAD51 homolog, RAD51B

The highly conserved Saccharomyces cerevisiae RAD51 protein functions in both mitotic and meiotic homologous recombination and in double-strand break repair. Screening of the public cDNA sequence database for RAD51-like genes led to the identification of a partial sequence from a breast tissue library present in the I.M.A.G.E. (Integrated Molecular Analysis of Genes and their Expression) collection. An extended 1764-bp cDNA clone encoding an open reading frame of 350 amino acids was isolated. This clone showed significant amino acid identity with other human RAD51 homologs. The new homolog, named RAD51B, was mapped to human chromosome 14q23-q24.2 using a panel of human-hamster somatic cell hybrids and fluorescence in situ hybridization. Northern blot analysis demonstrated that RAD51B mRNA is widely expressed and most abundant in tissues active in recombination. Functions associated with known RAD51 homologs suggest a role for RAD51B in meiotic recombination and/or recombinational repair.

Cloning, sequencing, gene organization, and localization of the human ribosomal protein RPL23A gene

The intron-containing gene for human ribosomal protein RPL23A has been cloned, sequenced, and localized. The gene is approximately 4.0 kb in length and contains five exons and four introns. All splice sites exactly match the AG/GT consensus rule. The transcript is about 0.6 kb and is detected in all tissues examined. In adult tissues, the RPL23A transcript is dramatically more abundant in pancreas, skeletal muscle, and heart, while much less abundant in kidney, brain, placenta, lung, and liver. A full-length cDNA clone of 576 nt was identified, and the nucleotide sequence was found to match the exon sequence precisely. The open reading frame encodes a polypeptide of 156 amino acids, which is absolutely conserved with the rat RPL23A protein. In the 5' flanking region of the gene, a canonical TATA sequence and a defined CAAT box were found for the first time in a mammalian ribosomal protein gene. The intron-containing RPL23A gene was mapped to cytogenetic band 17q11 by fluorescence in situ hybridization.

5-Fluorouracil interferes with paclitaxel cytotoxicity against human solid tumor cells

Paclitaxel, a naturally occurring antimitotic agent, has shown efficacy in the treatment of certain solid tumors, particularly metastatic breast carcinoma and drug-refractory ovarian cancers. Recent studies have demonstrated that paclitaxel, in addition to its effects on microtubules and cell cycle arrest, possesses significant cell-killing activity in solid tumor cells by the induction of apoptosis. However, the mechanism by which paclitaxel leads to cell death and its relationship with paclitaxel-induced mitotic arrest is presently unclear. In this study, we attempted to determine whether pre-arresting tumor cells at other phases of the cell cycle could affect paclitaxel-induced apoptosis. We found that 5-fluorouracil (5-FU), another antineoplastic agent that usually arrests tumor cells at the G1-S phase of the cell cycle, could significantly repress the cell-killing activity of paclitaxel in solid tumor cells, even when it was added simultaneously with paclitaxel. Further studies indicated that 5-FU actually inhibits the cytotoxic effects of paclitaxel on both mitotic arrest and apoptotic cell death, suggesting that 5-FU might interfere with paclitaxel cytotoxicity at an early stage, probably by preventing tumor cells from entering G2-M phase. Because recent clinical trials have used a combination of paclitaxel and 5-FU in the treatment of metastatic breast cancers, our results also suggest that the combination of these two drugs might not be as valuable in clinical chemotherapy.

[The relationship between smoking and periodontal diseases]

The oral hygiene, periodontal status and smoking habits of 432 males were surveyed in order to study the relationship between smoking and periodontal disease. The results showed that there was no difference between smokers and non-smokers on oral hygiene and gingivitis. The percentage of smokers with periodontitis was higher than that of non-smokers. The prevalence of periodontitis in heavy smokers was higher than that of light and middle smokers and non-smokers. It was indicated that smoking may be one of the risk factors in the development of periodontal disease.

Molecular cloning of TA16, a transcriptional repressor that may mediate glucocorticoid-induced growth arrest of leiomyosarcoma cells

The DDT1 MF2 smooth muscle tumor cell line was derived from an estrogen/androgen-induced leiomyosarcoma that arose in the ductus deferens of a Syrian hamster. The growth of this cell line is arrested at the G0/G1 phase of the cell cycle after treatment with glucocorticoids. To identify the putative gene(s) that are potentially involved in this hormone-induced cell growth arrest, we have used a differential screening technique to clone those genes whose expression is induced or up-regulated by glucocorticoids. A number of glucocorticoid response genes were thereby isolated from the leiomyosarcoma cells. One of these clones, termed TA16, was found to be markedly up-regulated by glucocorticoids in DDT1 MF2 cells, but only marginally changed in GR1 cells, a glucocorticoid-resistant variant that was selected from the wild type DDT1 MF2 cell. Isolation and sequencing of its intact cDNA indicated that the TA16 encodes a protein 485 amino acids long, and its sequence is closely homologous to a novel transcriptional repressor that presumably represses the transcription activity of some zinc finger transcriptional factors through a direct interaction. Transfection assays demonstrated that introduction of an antisense TA16 cDNA expression vector, controlled by an MMTV promoter, into the DDT1 MF2 cell significantly relieved the glucocorticoid-induced cell growth arrest. This finding suggests that TA16 might participate in the mediation of glucocorticoid-induced cell cycle arrest in leiomyosarcoma cells.

[CT diagnosis of maxillary sinus diseases]

To evaluate the diagnostic value of CT scan in maxillary sinus diseases, CT findings in 100 cases of maxillary sinus diseases, which included 64 inflammatory diseases; 14 benign tumors; 17 malignant tumors and 5 fractures The result showed that the accordance rate between CT scan and operative diagnosis was 95.0%; between CT scan and pathology was 92.6%(88/95). It is concluded that CT scan showed a better visualization of maxillary sinus than X-ray tomogram.

[Extraction-flame atom absorption determination of trace copper, zinc, cadmium and iron in bones]

Trace content of Cu, Zn, Cd and Fe in bones is determined by flame atomic absorption spectrometry after preceding preconcentration using the extraction system O-phenanthroline-sodium perchlorate/1, 2-dichloroethane. Also, the factors of influence were studied. The method was simple, accurate and reliable, The detection limits were Cu: 0.038microg/ml, Zn: 0.0042microg/ml, Cd: 0.0019microg/ml, Fe: 0.02microg/ml. The recovery rate was between 92.8 and 105%.

[Cloning of genes associated with taxol-induced apoptosis of human breast cancer cells]

The method of mRNA differential display was employed to isolate expressing genes involved in taxol-induced apoptosis of human breast cancer cells (BCap 37). Results demonstrated that the expressive alteration of twelve clones isolated was associated with taxol-induced apoptosis identified by Northern blot. cDNA sequence of clone C3P3 was highly homologous (99%) to human S-adenosylmethionine (S-AdoMet) synthetase. Increased transcriptional level of clone C3P3 induced by taxol was parallel to enhanced enzyme activity of S-AdoMet synthetase. These results suggested that the expression of these clones isolated by the mRNA differential display be possibly involved in the regulation of taxol-induced apoptosis. Their function in details need further study.

[Influence of intercellular adhesion molecule-1 transcription on nasal epithelial cell by airborne allergenic pollens]

Eleven patients with Artemisia allergic rhinitis were evaluated. Among them 8 were studied during pollen season and 3 out of pollen season. Intercellular adhesion molecule-1(ICAM-1) was detected on nasal epithelial cells by reverse transcription polymerase chain reaction (RT-PCR). The results showed that ICAM-1 was detectable from all samples in the pollen season. However, during off-pollen season 2 of the 3 samples were negative, 1 was positive (who was also positive to house dust). It is suggested that ICAM-1 is detectable on nasal epithelial cells during exposure to specific allergen.