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Biomedical subjects

G Shen

Publications and source records attributed to G Shen.

126 records · Page 7Linked to original sources
PubMed1992

Enumeration of T, B and natural killer peripheral blood cells of patients with multiple sclerosis and controls.

The median percentages of peripheral blood immunoglobulin-positive (Ig+) lymphocytes (8%, n = 46), CD8+ (12%, n = 49) and CD57+ cell numbers (5%, n = 37) of patients suffering from multiple sclerosis (MS) were significantly (p less than 0.05) lower than the values of age- and sex-matched healthy individuals (Ig+ cells: 13%, n = 46; CD8+ cells: 17%, n = 49; CD57+ cells: 9%, n = 37). Comparison of calculations on decreased peripheral blood cell counts and increased brain cell counts in MS patients revealed that sequestration of blood cells into the MS brain is a possible explanation of these findings.

Adult↗
PubMed1992

Pharmacokinetics of ribostamycin in paediatric patients.

In the present study, ribostamycin concentrations in serum were measured by microbiological assay in 20 paediatric patients aged 3 months to 11 years after intramuscular ribostamycin 10, 15 and 20 mg/kg. All pharmacokinetic parameters and statistical analyses were calculated by computer. These results showed that the absorption rate constant (ka), elimination rate constant (ke), time to peak serum concentration (tmax), elimination half-life (t1/2), apparent volume of distribution (Vd/F), total body clearance (CL) and area under the serum concentration-time curve (AUC) were significantly different in infants under 6 months from those in children over 3 years (p less than 0.05), except for the peak serum concentration (Cmax) and lag time from administration to the first appearance of drug in the serum (tlag) [p greater than 0.05]. The absorption of ribostamycin in infants was more rapid than that in children, but elimination was slower (p less than 0.05). The Vd/F and CL in infants were also larger than in children (p less than 0.01). There were significant positive correlations between Cmax, AUC and ribostamycin dosage (p less than 0.01). Pharmacokinetic parameters for infants and children were compared with those observed in adults, and it was found that ribostamycin absorption and elimination were more rapid in the paediatric patients. The Cmax in children and infants after intramuscular ribostamycin 10 mg/kg approached that in adults after an intramuscular dose of ribostamycin 500mg. Using a 1-compartment open pharmacokinetic model, the optimum intramuscular ribostamycin administration interval was estimated as 6.01 and 7.56h for children and infants, respectively, while the value was 8.5h in adults. When the drug was administered in multiple doses of 15 mg/kg intramuscularly every 8h, no accumulation occurred in children. It is suggested that ribostamycin be administered in intramuscular doses of 10 to 15 mg/kg twice daily in infants and 3 times daily in children, respectively.

Absorption↗
PubMed1992

Sudden infant death syndrome in the Tel Aviv and Petah Tikva districts.

We studied the epidemiology and incidence of the sudden infant death syndrome (SIDS) in the Tel Aviv and Petah Tikva districts during the period April 1980 to March 1983. Sixty-nine infants were diagnosed as SIDS and 38 of them had autopsies. Four cases were excluded because their autopsy revealed other diagnoses. When calculating for 24,183 live births per year during the study period, the rate of SIDS was found to be 0.47-0.90:1,000 live births. Other epidemiologic characteristics were: female:male [corrected] ratio 1:1.3; peak incidence at 2-4 months age, with 80% before age 6 months; increased incidence during the autumn and winter months (85% of SIDS cases); and highest incidence between midnight and 8:00 AM (84% of SIDS cases). None of the infants had a history of a previous apparent life-threatening event. Birthweight of infants who died of SIDS was not significantly different from that in the general population. No statistical relation to DTP (diphtheria, tetanus, pertussis) vaccination was found. Half the cases had mild respiratory illness during the week that preceded the sudden death. The incidence of parental cigarette smoking was higher than in the general population (56.5% vs. 36-53%; P less than 0.005) as well as the incidence of maternal smoking during pregnancy. We conclude that the incidence of SIDS in Israel is relatively low. The epidemiologic characteristics of SIDS in Israel are very similar to the presentation of the syndrome in other countries.

Age Factors↗
PubMed1992

[Application of the "Wits" approsal in Shanghai children with normal mixed or early permanent dentition]

128 children in Shanghai with normal mixed or early permanent dentition were selected in this servey to gain their normal value of the "wits" approsal.The results showed (1) there was no significant difference of "wits" approsal between the two groups of the children. (2)There was no disparity in "wits" approsal ofthe children with the same nationality and living in different regions. (3) There was a little change in value of the "wits" apporsal during the growth period or the children,which indicated a comparative identical relationship between the upper and lower basal bone.This study suggested that the application of the "wits" approsal be very imnportant in orthodontic clinic because of its expressing exactly the relationship of the jaws.

Journal Article↗
PubMed1992

[The effect of EBCI Iontophoresis on orthodontic tooth movement in rabbits]

The purpose of this study was to observe the effect of EBC ionophoresis on increasing the rate of tooth movement in rabbits.21 rabbits,in whose lower incisors the standard orthodontic appliances were placed,were divided into 3 groups at rendom which separately received iontoporesis of EBC,iontophosesis and injection of physiological saline at the submucosal area of the lower incisors.The results showed that the animals with EBC iontophoresis obtained tooth movement rate of 4.275+/-0.1214(mm) and the animals with NaCl iontophoresis and injection were respectively 3.337+/-0.4626(mm) and 2.178+/-0.2922(mm).The histological observation had also found the evidence of the ability of EBC to stimulate osteoclasts in preiodontal pression side and osteoblasts in tension.This study suggested that iontophoresis of EBC could play an important role in reconstructing the periodontum and speeding the tooth movement in rabbits.

Journal Article↗
PubMed1990

[Lymphocyte transformation responses to mitogens and specific antigens in patients with multiple sclerosis].

64 multiple sclerosis patients were studied for lymphocyte transformation responses to PHA, CON A, PWM and BMP. Some immunological parameter of multiple sclerosis patients, of patients with other neurological diseases and of healthy volunteers were compared. Mitogens (PHA, ConA and PWM) responsiveness of the peripheral blood mononuclear cells was significantly (P less than 0.05) diminished in multiple sclerosis patients compared to that of the blood donors. On the contrary MBP responsiveness was significantly increased after MBP exposure for 5 d. and 7 d. It was considered that the increased responsiveness was due to increased spontaneous proliferation.

Adult↗
PubMed1989

Immunomodulation of cimetidine in healthy volunteers.

The effect of cimetidine, a histamine H2-receptor antagonist, on the immune system in man was investigated in 11 healthy volunteers. Cimetidine was administered orally in daily doses of 800 mg for a period of 7 days. At the end of the administration period the number of peripheral CD8+ (cytotoxic/suppressor) cells had diminished significantly (P less than 0.05) along with a corresponding increase in the CD4+ (helper/inducer): CD8+ (cytotoxic/suppressor) cell ratio (P less than 0.01). Compared with pretreatment values, a significant in vitro blastogenic response to mitogen stimulation with concanavalin A (P less than 0.005), phytohemagglutinin (P less than 0.01), and pokeweed mitogen (P less than 0.05) was observed in lymphocytes of volunteers after cimetidine intake. The cell-mediated hypersensitivity as assessed by skin testing of seven recall antigens was also enhanced significantly (P less than 0.001). Using Spearman's coefficient of correlation to compare mitogen-stimulation tests and skin tests of delayed hypersensitivity to the CD4+:CD8+ ratio, yielded a positive correlation (r = 0.89; r = 0.85, respectively). These effects were reversible 96 h after the last cimetidine dose. In contrast, leukocytes, total T lymphocytes (CD2+, CD3+), CD4+ (helper/inducer) cells, natural killer cells (Leu7+), immunoglobulins, and total complement, C3, C4 were unaffected by cimetidine administration.

Adult↗
PubMed1987

Relative and absolute numbers of human lymphocyte subpopulations. A comparison of immunofluorescence microscopy and flow cytometric methodologies with special reference to precision and reference values.

Lymphocyte subpopulations were determined in blood samples from blood donors (40 women and 45 men) using immunofluorescence microscopy and flow cytometric methodologies. The study demonstrates the value of both methods for the enumeration of lymphocyte subpopulations. The advantages of employing an automated flow cytometer system are better precision and speed. The automated systems require a large initial technical and financial burden and are therefore probably destined to be reserved for the larger laboratory. There is a need for an adequate lymphocyte standard which shows little variation between aliquots and can be used for interlaboratory comparisons.

Adolescent↗
PubMedDate not supplied

Mechanical evaluation of the Dwyer screw-cable attachment.

A critical portion of the Dwyer technique is the crimping of the screw head to prevent the cable from slipping. Initally, Dwyer designed a hydraulic mechanism to crimp the screw head. However, this instrument was cumbersome to use and presented potential sterility problems. Today the Simmons crimper is used by the majority of orthopaedic surgeons. It is the purpose of this paper to report the studies conducted on 1) different materials used for the fabrication of the screws, and 2) the significance of the variations in the jaw opening using the Simmons mechanical crimper.

Evaluation Studies as Topic↗
PubMedDate not supplied

An approach to pathogenesis of male infertility with anti-sperm antibodies.

OBJECTIVE: To determine subsets and functional characteristics of peripheral blood lymphocytes in men with infertility associated with anti-sperm antibodies. SUBJECTS AND METHODS: Blood from 28 infertile men with anti-sperm antibodies and 34 fertile control males were tested for the lymphocyte subsets by indirect immunofluorescence and also for lymphocyte transformation responses to phytohemagglutinin (PHA), ConA, and pokeweed mitogen (PWM). Also studied were effects of seminal plasma on the lymphocyte transformation responses. RESULTS: Percentages of CD3, -4, and -8 cells and lymphocyte blastogenic responses to PHA and ConA were significantly lowered in patients. Percentage of B-cells, CD4/CD8 ratio, and blastogenic response to PWM were increased. All seminal plasmas suppressed lymphocyte blastogenesis induced by PHA, PWM, and ConA, but the suppressive effect on PHA and PWM by patients' plasma was less than that of controls. CONCLUSIONS: The results suggest that number and function of T-lymphocytes, especially CD8 cells, are lessened and those of CD4 and B-cells enhanced in the infertile patients. These factors would be conducive to development of an immunologic response to sperm.

Adult↗