[Advances in the study of proto-oncogene c-erbB-2].
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Animals↗
Biomedical subjects
K Jiang
Publications and source records attributed to K Jiang.
[Effect of antisense c-erbB2 on biologic behaviour and chemotherapeutic drug sensitivity in human ovarian cancer cells].
OBJECTIVE: To explore the effects of antisense erbB2 on the biological behaviours and on chemotherapeutic drug sensitivity in human ovarian cancer cells. METHODS: A recombinant retroviral expression vector: pDOR-erbB-neo was constructed which contain the neomycin resistant gene and the erbB2 cDNA 3.8kb antisense fragment. pDOR-erbB-neo was introduced into human ovarian cancer cell line SKOV3 by lipofectin. The cells were selected with geneticin (G418). The cells transfected with pDOR-erbB-neo were named SKOV3-A2. RESULTS: Southern blot analysis confirmed the presence of the antisense erbB2 in transfected cells. Transfected cells showed no obvious changes in morphology. Compared with parental cells and with pDOR-neo transfected cells used as controls, the growth and DNA synthesis of antisense transfected cells, SKOV3-A2, were inhibited. Transfection with pDOR-erbB-neo rendered the cells significantly, more sensitive to chemotherapeutic drugs (5-fluorouracil, cisplatinum) than the parental cells. CONCLUSIONS: The effectiveness and the potentiality of antisense erbB2 in ovarian cancer gene therapy is demonstrated. c-erbB2 oncogene may be related to drug resistance in ovarian cancer cell.
Antineoplastic Agents↗
The role of Leptotrombidium scutellare in the transmission of human diseases.
OBJECTIVE: To investigate the role of Leptotrombidium (L.) scutellare in the transmission of hemorrhagic fever with renal syndrome (HFRS) and tsutsugamushi disease of autumn-type. MATERIALS AND METHODS: Four criteria were used to ascertain this mite as transmitting vector of disease: (1) epidemiological evidence; (2) natural infection of pathogen; (3) ability to transmit pathogen via biting; (4) ability to transfer pathogen via transovarian route. RESULTS: The results indicated that L. scutellare was the dominant species of chigger mite on rats. Its seasonal distribution was correlated with the incidence of these two diseases. This mite could be naturally infected by HFRS virus (HFRSV) and Rickettsia tsutsugamushi (Rt) and the mite could transmit HFRSV and Rt to vertebrates by biting and to its offspring via transovarian transmission. CONCLUSIONS: These results have proved that L. scutellare can be a transmitting vector of HFRS and tsutsugamushi disease of autumn-type.
Animals↗
1,25-Dihydroxyvitamin D3 stimulates the phosphorylation of two acidic membrane proteins of 42,000 and 48,000 daltons in rat colonocytes: an effect modulated by vitamin D status.
Our laboratory has recently demonstrated that 1,25-dihydroxyvitamin D3(1,25(OH)2D3) rapidly stimulated membrane polyphosphoinositide breakdown and increased intracellular calcium, as well as activated protein kinase C (PKC) in vitamin D-sufficient rat colonocytes. These effects of 1,25(OH)2D3 were, however, lost in vitamin D-insufficient rats and restored by the in vivo repletion of 1,25(OH)2D3. In the present studies we have examined the ability of 1,25(OH)2D3 to stimulate the phosphorylation of colonic membrane proteins in intact D-sufficient cells. In addition, we investigated the effects of vitamin D status on the phosphorylation of these membrane proteins in broken cell preparations. These studies demonstrated that 1,25(OH)2D3 increased the phosphorylation of at least two colonic membrane proteins with apparent molecular weights of 42,000 (pp42) and 48,000 (pp48) in intact cells of vitamin D-sufficient rats. Moreover, in vitamin D-sufficient rats, treatment of colonocytes with 1,25(OH)2D3 or 12-O-tetradecanoyl phorbol 13-acetate (TPA), a known activator of PKC, significantly increased the phosphorylation of pp42 and pp48 in broken cell preparations. The kinetics of these phosphorylations in response to 1,25(OH)2D3 were both rapid and transient. In addition, PKC19-36, a specific PKC inhibitor, decreased the phosphorylation of pp42 and pp48, whereas okadaic acid (OA), a type 1 and 2A protein phosphatase inhibitor, further augmented their phosphorylation in response to 1,25(OH)2D3. The isoelectric points of pp42 and pp48 were 5.79 and 5.97, respectively, and both were predominantly phosphorylated on threonine residues. In contrast to our findings in colonocytes from vitamin D-sufficient animals, basal phosphorylation of pp42 and pp48 were increased in membranes prepared from vitamin D-insufficient rats. Moreover, these phosphorylations failed to change in response to 1,25(OH)2D3-treatment of colonocytes from vitamin D-insufficient rats. The basal phosphorylation of each of these proteins was restored to control levels, as was their ability to respond to the direct addition of 1,25(OH)2D3 following the in vivo repletion of vitamin D-insufficient rats with this secosteroid. In summary, we have identified two acidic membrane proteins from rat colonocytes that are phosphorylated in both intact and broken cell preparations in response to 1,25(OH)2D3 treatment, an event modulated by vitamin D status and mediated, at least in part, by PKC.
Animals↗
Pivot/Remote: a distributed database for remote data entry in multi-center clinical trials.
1. INTRODUCTION. Data collection is a critical component of multi-center clinical trials. Clinical trials conducted in intensive care units (ICU) are even more difficult because the acute nature of illnesses in ICU settings requires that masses of data be collected in a short time. More than a thousand data points are routinely collected for each study patient. The majority of clinical trials are still "paper-based," even if a remote data entry (RDE) system is utilized. The typical RDE system consists of a computer housed in the CC office and connected by modem to a centralized data coordinating center (DCC). Study data must first be recorded on a paper case report form (CRF), transcribed into the RDE system, and transmitted to the DCC. This approach requires additional monitoring since both the paper CRF and study database must be verified. The paper-based RDE system cannot take full advantage of automatic data checking routines. Much of the effort (and expense) of a clinical trial is ensuring that study data matches the original patient data. 2. METHODS. We have developed an RDE system, Pivot/Remote, that eliminates the need for paper-based CRFs. It creates an innovative, distributed database. The database resides partially at the study clinical centers (CC) and at the DCC. Pivot/Remote is descended from technology introduced with Pivot [1]. Study data is collected at the bedside with laptop computers. A graphical user interface (GUI) allows the display of electronic CRFs that closely mimic the normal paper-based forms. Data entry time is the same as for paper CRFs. Pull-down menus, displaying the possible responses, simplify the process of entering data. Edit checks are performed on most data items. For example, entered dates must conform to some temporal logic imposed by the study. Data must conform to some acceptable range of values. Calculations, such as computing the subject's age or the APACHE II score, are automatically made as the data is entered. Data that is collected serially (BP, HR, etc.) can be displayed graphically in a trend form along with other related variables. An audit trail is created that automatically tracks all changes to the original data, making it possible to reconstruct the CRF to any point in time. On-line help provides information on the study protocol as well as assistance with the use of the system. Electronic security makes it possible to lock certain parts of the CRF once it has been monitored. Completed CRFs are transmitted to the DCC via electronic mail where it is reviewed and merged into the study database. Questions about subject data are transmitted back to the CC via electronic mail. This approach to maintaining the study database is unique in that the study data files are distributed among the CC and DCC. Until a subject's CRF is monitored (verified against the original patient data residing in the hospital record), it logically resides at the CC where it was collected. Copies are transmitted to the DCC and are only read there. Any pre-monitoring changes must be made to the data at the CC. Once the subject's CRF is monitored, it logically moves to the DCC, and any subsequent changes are made at the DCC with copies of the CRF flowing back to the CC. 3. DISCUSSION. Pivot/Remote eliminates the need for paper forms by utilizing portable computers that can be used at the patient bedside. A GUI makes it possible to quickly enter data. Because the user gets instant feedback on possible error conditions, time is saved because the original data is close at hand. The ability to display trended data or variables in the context of other data allows detection of erroneous conditions beyond simple range checks. The logical construction of the database minimizes the problem of managing dual databases (at the CC and DCC) and keeps CC personnel in the loop until all changes are made.
Computer Communication Networks↗
Comparison of survival probabilities for dialysis patients vs cadaveric renal transplant recipients.
OBJECTIVE: To compare mortality risk among cadaveric renal transplant recipients vs transplant candidates on dialysis in the cyclosporine era. SETTING: Patient mortality risk was analyzed by treatment modality for a completed statewide patient population. PATIENTS: All Michigan residents younger than age 65 years who started endstage renal disease (ESRD) therapy between January 1, 1984, and December 31, 1989, were included. Patients were followed up from ESRD onset (n = 5020), to wait-listing for renal transplant (n = 1569), to receiving a cadaveric first transplant (n = 799), and to December 31, 1989. MAIN OUTCOME MEASURE: Mortality rates. RESULTS: Using a time-dependent variable based on the waiting time from date of wait-listing to transplantation and adjusting for age, sex, race, and primary cause of ESRD, the relative risk (RR) of dying was increased early after transplantation and then decreased to a beneficial long-term effect, given survival to 365 days after transplantation (RR, 0.36; P < .001). This lower long-term risk was most pronounced (RR, 0.25) among diabetic transplant recipients compared with diabetic wait-listed dialysis patients (P < .001) and not observed among patients with glomerulonephritis as cause of ESRD (P > .05). Overall, the estimated times from transplantation to equal mortality risk was 117 +/- 28 days and to equal cumulative mortality was 325 +/- 91 days. CONCLUSIONS: The overall mortality risk following renal transplantation was initially increased, but there was a long-term survival benefit compared with similar patients on dialysis. These analyses allow improved description of comparative mortality risks for dialysis and transplant patients and allow advising patients regarding comparative survival outcomes.
Cadaver↗
[The study of occurrence mechanism in acute and chronic cerebral vasospasm].
Using radioimmunoassay, fluorescence and transmittal++ electronmicroscopy, we studied the of prostaglandin(PG), lipid peroxidation(LPO) and ultrastructure. Fresh arterial blood (imaging acute spasm) produced basilar arterial spasm strongly(+ + +) and vacuole deterioration in vascular walls but there were no changes in 6-keto-PGF1 alpha and TXB2 and PGE2 and LPO. Incubated arterial blood (imaging chronic spasm) produced basilar arterial spasm markedly (+ + +) also. Vacuole deterioration in vascular walls either, and decreased the level of 6-keto-PGF1 alpha apparently (P < 0.01) and elevated the content of LPO significantly (P < 0.01) and there were no changes in the level of TXB2 and PGE alpha. This experiment suggests that the mechanism of acute spasm and chronic spasm is different.
6-Ketoprostaglandin F1 alpha↗
A graphical ICU workstation.
A workstation designed to facilitate electronic charting in the intensive care unit is described. The system design incorporates a graphical, windows-based user interface. The system captures all data formerly recorded on the paper flowsheet including direct patient measurements, nursing assessment, patient care procedures, and nursing notes. It has the ability to represent charted data in a variety of graphical formats, thereby providing additional insights to facilitate the management of the critically ill patient. Initial nursing evaluation is described.
Attitude of Health Personnel↗
[Changes in lipid peroxides and superoxide dismutase as incubation of in vitro erythrocytes with cerebrospinal fluids and the action of various scavengers of free radicals].
In this experiment, LPO increased and SOD reduced as the time pass when erythrocytes (RBC) and CSF were mixed and incubated. There was a negative relationship between LPO and SOD. LPO in RBC of arterial blood was higher than that of venous blood after incubation for 3 days (P less than 0.01). When arterial RBCs were incubated together with various scavengers of free radical (SOD catalase and histidine and mannitol), the production of LPO was less than that of arterial RBC incubation singly (P less than 0.01). The change of LPO was not reduced when sodium nitrite and arterial RBC incubated. The results demonstrated that the scavengers of free radicals could be eliminated free radical but failed with sodium nitrite.
Animals↗
A new method for the synthesis of a structural gene.
A novel method of synthesizing a structural gene or gene fragment, consisting of the first synthesis of a single-stranded DNA (ssDNA), has been developed. As a preliminary test of this method, four synthetic genes or gene fragments have been synthesized. The first one with 396 base pairs (b.p.) codes for the mature rbcS from wheat, the next two with 370 and 342 b.p. respectively, for two half molecules of a gene for trichosanthin and the last one with 315 b.p. for the N-terminal 1-102 residues of human prourokinase. In all these syntheses, a plus-stranded DNA of the target gene was generally assembled by a stepwise or one step T4 DNA ligase reaction of six oligonucleotides (A, *pB, *pC, *pD, *pE and *pF) of 30-71 nucleotides long in the presence of two terminal complementary oligonucleotides (Ab' and eF') and three short inter-fragment complementary oligonucleotides (bc, cd and de). After purification, the synthetic ssDNA was inserted into a cloning vector, pWR13. The resulting product was directly used to transform a host cell. The structure of the cloned synthetic gene was confirmed by DNA sequence analysis.
Base Composition↗
A knowledge-based experimental design system for nucleic acid engineering.
Presented in this paper is a knowledge-based experimental design system that incorporates the domain expertise used in nucleic acid engineering, thus automating the processing of error-prone, laborious low-level work, and many decision-making steps, and guiding the biologist toward a workable plan. This allows the biologist to work at a higher abstraction level, concentrating on more fundamental, difficult and challenging problems directly related to protein structure - function relationships. Cassette-based site-directed mutagenesis and synthetic gene designs are used as examples to illustrate the utility of the knowledge-based system approach to experimental design.
Algorithms↗
Structural characterization of intact, branched oligosaccharides by high performance liquid chromatography and liquid secondary ion mass spectrometry.
We report results of a mass-spectrometric-based strategy for determining the detailed structural features of N-linked oligosaccharides from glycoproteins. The method was used to characterize a series of intact, high mannose oligosaccharides isolated from human immunoglobulin M (IgM). The IgM was purified from a patient with Waldenstrom's macroglobulinemia. The strategy included releasing the oligosaccharides by digestion of the purified glycoprotein with endoglycosidase H, separating the released oligosaccharides by high resolution gel filtration, and derivatizing the resulting reducing termini with the uv-absorbing moiety, ethyl p-aminobenzoate. This particular derivative facilitates HPLC detection and provides centers for protonation and deprotonation enhancing liquid secondary ion mass spectra. Positive and negative ion spectra contained molecular species of similar abundance. However, fragment ion peaks yielding sequence information were significantly more prominent in the negative ion mass spectra. Furthermore, it was obvious that the fragmentation patterns differed substantially for linear and branched oligomers. For linear oligosaccharides, a smooth envelope of fragment ions was observed; from low to high mass there was an ordered decrease in ion abundance from both the reducing and nonreducing termini. This pattern of fragment ions was not observed for branched oligosaccharides since in these cases fragments at certain masses could not arise by single bond cleavages. Therefore, these fragments were either significantly reduced in abundance or absent as compared with identical fragments formed from linear molecules. Importantly, 200 pmol of an oligosaccharide could be derivatized, separated, and detected by mass spectrometry, allowing identification of previously unreported minor components of the IgM oligosaccharides. Therefore, this experimental strategy is particularly useful for the purification and detailed structural characterization of low abundance oligosaccharides isolated from heterogeneous biological samples.
Carbohydrate Conformation↗
A knowledge-based system for cassette mutagenesis experimental design.
A knowledge-based system for the design and planning of cassette mutagenesis experiments has been developed for scientists working in the field of structural biology and protein engineering. The system applies domain-specific knowledge to manage the menial details and automate most of the decision-making steps involved in the design process. This allows scientists to work at a high abstraction level, and results in significant time savings and increased productivity. The system also includes an automated documentation facility to improve the efficiency and accuracy of record keeping.
Artificial Intelligence↗
Liquid and solid two-phase radioimmunoassay--simultaneous measurement of levels of triiodothyronine and thyroxine of human serum in a single specimen.
The principle of the liquid and solid two-phase radioimmunoassay and its application to measuring the concentrations of triiodothyronine and thyroxine of human serum in a single sample at the same time are described in this paper. Rabbit anti-triiodothyronine antiserum was immobilized on the inner surface of a plastic tube as solid-phase radioimmunoassay system of testing triiodothyronine and donkey anti-rabbit gamma globulin antiserum was used to separate immunocomplex in liquid-phase radioimmunoassay system of thyroxine reaction. In both systems, radioiodine-125-labelled antigens were used as tracer. Through simple calculation, we can get the results of serum concentrations of triiodothyronine and thyroxine in a single sample. Compared with classical single-component radioimmunoassay of triiodothyronine and thyroxine and by methodological appraisal of two-phase radioimmunoassay itself, this method has the advantages of very high efficiency, reliability and also has the same specificity and precision.
Humans↗
Comparison of dibenzodioxin levels in blood and milk in agricultural workers and others following pentachlorophenol exposure in China.
Substantial amounts of sodium pentachlorophenol (Na-PCP) salts have been sprayed in certain areas in central China since the 1960s for control of snail-borne schistosomiasis. A sample of Na-PCP used in the area of concern was analyzed and showed 2,3,7,8-substituted dibenzodioxin (PCDD) and dibenzofuran (PCDF) congeners as well as some non-2,3,7,8-substituted congeners. Dibenzodioxin analysis of two pooled blood samples from 100 persons living in sprayed areas and a pooled sample from 26 individuals who had direct contact with the Na-PCP showed elevations of PCDD/F congeners found in the Na-PCP. Total PCDD/Fs ranged from 631 to 1252 parts per trillion (ppt) lipid in the blood of those exposed to Na-PCP, while two general population age-matched pooled blood samples from 50 persons each had total PCDD/Fs of 147 and 178 ppt. Toxic equivalents calculated with International Toxic Equivalency Factors (I-TEqs) ranged from 9 to 16.3 ppt in the blood samples from exposed persons while the general population blood I-TEqs were 4.8 and 6.4 ppt. A pooled breast milk sample from 50 women living in the sprayed areas was compared with a pooled sample from 50 women living in unsprayed areas. Total PCDD/Fs was low in both exposed and general population samples (134 and 42 ppt lipid, respectively), however, the women living in sprayed areas had considerably higher PCDDs, 129 ppt versus 34 ppt. The mothers exposed to Na-PCP had a I-TEq of 5.4, which was about double that of the mothers from the general population, 2.6 ppt, lipid. Although human PCDD and PCDF tissue levels in China are low compared with those in more industrialized countries, the higher levels in exposed persons are cause for concern.
Adolescent↗
Mechanism of adenoviral-mediated CTLA4-IG gene-induced pancreatic allograft tolerance in rats.
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Abatacept↗
Long-term survival following canine intrathymic islet allograft transplantation with short-course immunosuppressive therapy.
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Animals↗
Long-term localized transgene expression in the pancreas achieved by intra-arterial adenoassociated virus-mediated gene transfer.
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Adenoviridae↗