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Biomedical subjects

Y Sun

Publications and source records attributed to Y Sun.

At least 883 records · Page 49Linked to original sources
PubMed1994

A polymeric drug delivery system for the simultaneous delivery of drugs activatable by enzymes and/or light.

Three water soluble copolymers based on N-(2-hydroxypropyl)methacrylamide were prepared. Copolymer I contains adriamycin, a chemotherapeutic agent, attached via enzymatically degradable oligopeptide (glycylphenylalanylleucylglycine; G-F-L-G) side chains. The other two copolymers contained the photosensitizer, meso-chlorin e6 monoethylene diamine disodium salt (Mce6). In Copolymer II, the chlorin is attached via the degradable G-F-L-G sequence, and it was bound by the nondegradable glycyl spacer in Copolymer III. Initially, the copolymers were characterized separately in vitro and in vivo. Combinations of the copolymer bound chemotherapeutic agent and each of the copolymer bound photosensitizers were then assessed for antitumor effect in vivo. Localization/retention studies (A/J mice; Neuro 2A neuroblastoma solid tumor) were performed with the two copolymers containing Mce6 as well as the free drug. Results of these experiments demonstrated a very different tumor uptake profile for the two copolymers. While the free drug was rapidly cleared from tumor tissue, the copolymer containing Mce6 attached via the non-degradable bond was retained for an extended period; drug concentrations in the tumor were high even after 5 days. On the other hand, a high concentration of the copolymer containing Mce6 bound via the degradable sequence was taken up by the tumor, yet its concentration in the tumor was substantially diminished at 48 h after administration. This shows indirect evidence of in vivo cleavage of Mce6 from the copolymer in the lysosomal compartment which is supported by direct evidence of cleavage by cathepsin B (a lysosomal enzyme) in vitro. Antitumor effects were assessed on Neuro 2A neuroblastoma induced in A/J mice for all three copolymers. Photodynamic therapy (PDT) proved the copolymer with Mce6 bound via the degradable oligopeptide sequence to be a more effective photosensitizer in vivo than the other chlorin containing copolymer. The difference in activity was consistent with the results obtained by photophysical analyses in which the free drug had a higher quantum yield of singlet oxygen generation than the polymer bound drug in buffer. The quantum yield of singlet oxygen generation increased with the enzymatic cleavage of the chlorin from the copolymer. Conditions were subsequently determined for which chemotherapy or PDT would show some antitumor effect, yet be incapable of curing tumors. Finally, combination therapy experiments were performed in which the copolymer bound adriamycin was mixed with either of the copolymer bound chlorin compounds and injected intravenously (i.v.) into the tail veins of mice.(ABSTRACT TRUNCATED AT 400 WORDS)

Acrylamides↗
PubMed1994

[Therapeutic effectiveness of zuzhongping on patients with arteriosclerostic cerebral infarction].

Forty-six patients with acute arteriosclerostic cerebral infarction were randomly divided into two groups: control group and treatment group. Each of them included 23 patients respectively. The patients in the control group were given Dextran-40 but the ones in the treatment group were given the mixture of Zuzhongping. The course of treatment was 3 weeks. It was found that there was a significant difference (P < 0.01) in the score percentage, before and after treatment of neurological defects, between the control group and the treatment group, and the former (29.70 +/- 33.52) was much lower than the latter (45.40 +/- 27.60). The total curative rate of the treatment group (87.0%, 20/23) was significantly higher than that of the control group (60.9%, 14/23). There was an obviously prolonged KPTT (kaolin partial thromboplastin time) value and a decreased Fb (fibrinogen) level in the treatment group. Before treatment they were 32.43 +/- 4.03 sec and 6.18 +/- 1.77 g/L respectively, but after treatment, 52.96 +/- 10.50 sec and 4.5 +/- 0.95 g/L respectively. The authors suggest that the significant therapeutic efficacy of Zuzhongping in the patients with acute arteriosclerostic cerebral infarction is related to its action of anticoagulation, modification of PGI2 and TXA2 level in the body, decreased blood Fb level, hyperglycemia, etc.

Aged↗
PubMed1994

[Clinical study of recombinant human granulocyte colony-stimulating factor (RHG-CSF) on leucopenia induced by chemotherapy with CE regimen on lung cancer patients].

The authors have studied the efficacy and safety of recombinant human granulocyte colony-stimulating factor (rhG-CSF, Granulocyte Injection) on leucopenia and neutropenia induced by chemotherapy with regimen CE (Carboplatin and Etoposide) in lung cancer patients in a randomized, matched and cross-over clinical trial. The total enrolled patients were twenty-two. They were randomized into A and B groups (11 patients in each group). Each patient received two cycles treatment. In group A chemotherapy and rhG-CSF were used in the first cycle and chemotherapy alone was used in the second cycle, while in group B chemotherapy alone was used in the first cycle and chemotherapy and rhG-CSF were used in the second cycle. The results showed that rhG-CSF significantly increased the number of white blood cell (WBC) and absolute neutrophil count (ANC) at the nadir, decreased incidence of leucopenia and neutropenia, and reduced the number of days with WBC < 4.0 x 10(9)/L, ANC < 2.5 x 10(9)/L as well as the number of days with WBC > 4.0 x 10(9)/L and ANC > 2.5 x 10(9)/L. rhG-CSF ensures the completion of chemotherapy and its side-effects were slight.

Adult↗
PubMed1994

[CT analysis on correlation of parasagittal sinus and parafalx meningiomas with sagittal sinus and falx].

The computed tomographic characteristics of 59 cases of parasagittal sinus and parafalx meningiomas which were verified in operation and pathology are analysed. They were found as follows: (1) the striding sign of the tumor for the superior sagittal sinus and/or falx; (2) the smooth sign of the interior edge of the tumor; (3) the turning sign of the falx for one side of the tumor; and (4) the thickness and density increasing sign of the falx and/or sagittal. Based on the operation findings, the pathologic bases and clinical values are also discussed.

Adult↗
PubMed1994

[Response rate of small cell lung cancer treated with CE-CAP alternating chemotherapy].

From Sep. 1989 to Dec. 1992, 122 evaluable patients with small cell lung cancer (SCLC) treated with chemotherapy combined with radiotherapy in our hospital were analysed. There were 95 men and 27 women. The age ranged from 20 to 70 years. All were proven by pathology or cytology. They all did not receive previous treatment and had a measurable mass. Of them, 83 patients had limited disease (LD) and 39 extensive disease (ED). Using CE-CAP alternating chemotherapy, 48 LD and 27 ED were given two cycles, 35 LD and 12 ED four cycles. In this series, remission time was not evaluated because all patients received radiotherapy shortly after chemotherapy. Of 122 patients, 10 patients (8.2%) achieved CR, 89 (72.9%) PR, 18 (14.7%) S and 5 (4%) P. The total response rate was 81.1% (99/122), which is higher than that of COMVP and PE-CAV regimens. The response rates were 80.0% and 82.9% in two and four cycle groups, respectively. There was no significant difference between the two groups. The main toxicity observed was nausea, vomiting and bone marrow suppression, but were tolerated by the patients. In conclusion, CE-CAP regimen can be recommended as the treatment of choice in SCLC.

Adult↗
PubMed1994

[Study on incidence of acute flaccid paralysis in Hebei].

A study on the incidence of Acute Flaccid Paralysis (AFP) among 0-14 year-old children in 1990-1992 was carried out in all over 12 prefectures and cities level hospitals in Hebei. The county level hospitals were investigated in 3 of 12 prefectures and cities. A total of 214 hospitals were investigated. The result showed that the annual average incidence of AFP and non-polio AFP among 0-14 year-old children in 1990-1992 were 1.498/100000 and 0.988/100000, respectively. The annual average incidence of them among < 5 year-old children were 2.917/100000, 1.591/100000, respectively. The incidence of AFP and non-polio AFP were different in each prefecture and city. GBS accounts for 54.06% of all AFP cases.

Adolescent↗
PubMed1994

[Clinical study of recombinant human granulocyte-macrophage colony-stimulating factor on chemotherapy-induced leukopenia].

We have studied the efficacy and safety of recombinant human granulocyte-macrophate colony-stimulating factor (rhGM-CSF, leucomax) to treat leukopenia and neutropenia induced by chemotherapy with regimen CE (Carboplatin, Etoposide) and regimen CEA (Carboplatin, Etoposide, Adriamycin) on patients in a randomized comparative, cross-over clinical trial. Twenty-one patients enrolled were randomly divided into A(n = 8) and B group(n = 13). Each patient received two cycles of treatment. In group A, chemotherapy and rhGM-CSF were given in the first cycle and in the second cycle only chemotherapy was given. In group B, only chemotherapy was given in the first cycle and chemotherapy and rhGM-CSF were given in the second cycle. The results showed that rhGM-CSF significantly increased the total white cell count (WBC) and absolute neutrophil count (ANC) at nadir, decreased the incidence of leukopenia and neutropenia, and shortened the duration of leukopenia with WBC < 4.0 x 10(9)/L and ANC < 2.5 x 10(9)/L, and the number of days for recovery to WBC > 4.0 x 10(9)/L and ANC 2.5 x 10(9)/L. However, rhGM-CSF displayed little effect on platelets. The main side-effect of rhGM-CSF was fever (43%), as well as skin rashes and influenzalike symptoms.

Adult↗
PubMed1994

[A study on the degradation kinetics of nicotinamide powder].

The effect of temperature and humidity on the degradation of nicotinamide powder was studied below the critical relative humidity at temperatures 50-80 degrees C and relative humidities 50-80%. The rate equation of the degradation of nicotinamide under isothermal and constant humidity conditions is -dC/dt=k(Co-C)-1, where k is the apparent rate constant of degradation, Co and C are initial concentration and concentration at time t of nicotinamide, respectively. The relationship between the apparent rate constant of degradation and relative humidity RH is in K=a + m (RH), where a and m are constants. When RH are 50.35, 66.85, 75.33 and 80.35%, the apparent activation energies of degradation from Arrhenius equation are 219.94, 181.86, 168.99 and 153.89 kJ/mol, respectively. The rate equation the photodegradation of nicotinamide under room temperature is -dR/dt=K' (Ro-R)-1, where K' is the apparent rate constant of photodegradation, Ro and R are initial reflectance and reflectance at time t of nicotinamide, respectively.

Humidity↗
PubMed1994

[Changes in erythrocyte fluidity, fragility and deformability and serum lipid peroxide content in early burn period].

We have observed RBC membrane fluidity, serum lipid peroxide, RBC deformability and fragility in 10 burn patients on PBD 2.3-5 and 6-10. The results showed that there was a reduction of RBC membrane fluidity and, on the contrary, there was an elevation in the contents of serum lipid peroxide and RBC deformability and fragility (All P < 0.01). We consider that damage of RBC membrane by free radicals may be one of the reasons of the above changes, and anti-free radical drugs may be beneficial in protecting RBC structure and functions and blood circulation.

Adult↗
PubMed1994

Fuzzy logic assisted control of inspired oxygen in ventilated newborn infants.

The control of oxygen delivery to mechanically ventilated newborn infants is a time intensive process that must balance adequate tissue oxygenation against possible toxic effects of oxygen exposure. Investigation in computer assisted control of mechanical ventilation is increasing, although very few studies involve newborn infants. We have implemented a fuzzy controller for the adjustment of inspired oxygen concentration (FIO2) in ventilated newborns. The controller utilizes rules produced by neonatologists, and operates in real-time. A clinical trial of this controller is currently taking place in the neonatal intensive care unit (NICU) of Children's Hospital, Boston, MA.

Computer Systems↗
PubMed1994

Clinical observation and treatment of hyperkinesia in children by traditional Chinese medicine.

Sixty-six children with hyperkinesia were treated with the Yizhi (wit-increasing) syrup, after which their scores on behavior dropped, their school records improved, and the rate of appearance of soft neurotic signs lowered, all three changes being significant, giving a total effectiveness rate of 84.8%. After the treatment, examination of the 24-hour urine showed significant increases in its content of norepinephrine (NE), dopamine (DA), 3-4 dihydroxy phenylacetic acid (DOPAC), cyclic adenosine monophosphate (cAMP), and creatinine (Cr).

Adolescent↗
PubMed1994

Developmental and tissue-specific expression of prosaposin mRNA in murine tissues.

Prosaposin is a multifunctional locus in humans and mice that encodes in tandem and in the same reading frame four glycoprotein activators, or saposins, of lysosomal hydrolases. These ubiquitously expressed glycoproteins and the precursor, prosaposin, have been proposed to function in glycosphingolipid catabolic pathways and glycolipid transport. To characterize the temporal and spatial expression of the prosaposin locus, prenatal and postnatal mouse tissues were screened by in situ hybridization with a mouse antisense riboprobe for prosaposin. Prenatally, prosaposin mRNA was expressed differentially in the placenta and prominently in the decidua basalis and capsularis where expression was gestational age dependent. No other region of high-level expression was detectable in the prenatal mouse. In comparison, high-level differential expression of prosaposin was clearly evident postnatally in a variety of organs, including secretory epithelial cells of the choroid plexus, ependymal lining, upper trachea, esophagus, cortical tubules of the kidney, sertoli cells of the testes and epididymis. Discrete localization of prosaposin mRNA expression was also found in neurons of the cerebral cortex, cerebellar cortex, and lateral columns of the spinal cord as well as in hepatocytes of the mature liver. Very high levels of expression were found in specialized tissues including the Harderian glands and macrophages of lymph nodes, lungs, splenic tissue, and thymus. These studies indicate that the expression of the prosaposin locus, a presumed "housekeeping" gene, is under tissue- and cell-specific differential control. The spatial organization of expression suggests a role for this locus in the expression of glycosphingolipid-storage diseases.

Animals↗
PubMed1994

Human papillomavirus-related serological markers of invasive cervical carcinoma in Brazil.

Masked sera from 194 cases and 217 controls participating in a case-control study of cervical cancer in Brazil were examined for antibodies to human papillomavirus (HPV) 16 E6 and E7 by radioimmunoprecipitation assay. Radiolabeled full-length E6 and E7 proteins expressed by in vitro transcription and translation in rabbit reticulocyte lysate were used as antigens. The antibody prevalences in cases and controls were: 54.1% versus 6% for E6; 30.4% versus 4.6% for E7; 63.4% versus 10.1% for either E6 or E7; and 21.1% versus 0.5% for both E6 and E7. The corresponding odds ratios were 35 ([95% confidence interval (CI)], 15-83), 10 (95% CI, 4-25), 28 (95% CI, 13-61) and 87 (95% CI, 10-736). The most marked contrast between cases and controls was observed for sera with high antibody titers (cpm > 6000) with an odds ratio of 239 (95% CI, 29-1946) for E6 or E7. Seroreactivity in cases was partially type specific; women who had HPV-16 DNA in the genital tract had higher antibody prevalence rates than those who were negative for HPV DNA. Reactivity to the E6 protein was associated with the stage of disease; the antibody prevalence was 62.7% in cases with stages II-IV and 31.0% in cases with stage I (P < 0.005). HPV-16 serology and HPV polymerase chain reaction were compared as markers for invasive cervical cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Angiotensin-converting enzyme, bradykinin, and angiotensin II receptor binding in rat skin, tendon, and heart valves: an in vitro, quantitative autoradiographic study.

Angiotensin converting enzyme (ACE), an ectoenzyme bound to vascular endothelial cells, is also found at tissue sites (TACE) normally composed of fibrillar collagen and fibroblasts. For example, TACE is present in the adventitia of intramural coronary arteries and matrix of heart valves, as well as the fibrous tissue that follows the chronic administration of angiotensin II (AII) or aldosterone. At these sites bradykinin (BK) receptor but not AII receptor binding has been observed, suggesting that in fibrous tissue TACE uses BK as substrate. Dermis, subcutaneous tissue, and skeletal muscle tendon likewise are sites that are rich in fibrillar collagen but are different in their cellularity. Accordingly, we tested the hypothesis that TACE is normally present at sites of fibrous tissue and that BK--not AIK--receptor binding is anatomically coincident with TACE in keeping with its role as a kininase II. TACE and receptors for BK and AII were localized by quantitative in vitro autoradiography with [125I]351A, 125I[Tyr8]BK, and 125I[Sar1, Ile8]AII, respectively. Skin morphology was examined in serial full thickness sections obtained from the dorsum of Sprague-Dawley rats. We found the following: (1) high TACE binding occurred in subcutaneous connective tissue and heart valves that was displaced by lisinopril or 351A in a dose-dependent manner; (2) BK receptor binding and low density AII receptor binding were seen at these sites, where AII receptor binding was totally displaced by a type 1 (DuP753) but not a type 2 (PD123177) receptor antagonist; (3) ACE, BK, and AII receptor binding was not evident in epidermis, dermis, skeletal muscle, or tendon.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Experimental study of a new sutureless intraluminal graft with a shape-memory alloy ring.

A new sutureless intraluminal graft has been developed with a ring made of a titanium-nickel shape-memory alloy. The diameter of the ring can be reversibly reduced by compression in 4 degrees C normal saline solution and recovers its original shape in 38 degrees C physiologic saline solution during insertion in the aorta. The new graft was implanted in nine dogs and was evaluated histologically and angiographically at various intervals from 15 to 90 days. No complications, such as dislodgment, aortic rupture, stenosis, or aneurysmal dilation, were observed. The component of the shape-memory ring allows the graft to be introduced and secured in place easily. The function of this ring is better than that of the rigid ring.

Alloys↗