[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.

[Pathogenetic and clinical significance of peripheral activated T-lymphocyte subsets in Basedow's disease]

The peripheral activated T-cell subsets which express concurrently DR and CD antigens were determined in 22 patients with Graves' disease using the fluorescence-rosette double labelling technique. In the active phase of the disease a decrease in the percentage of CD8+ cells, an increase in the CD4+/CD8+ ratio and an elevation of various DR+CD+T-lymphocytes was found. A concurrent marked increase in DR+CD4+ cells accounts for an abnormality in the equilibrium of activated T-lymphocyte subsets and an increase in DR+CD4+/DR+CD8+ ratios. In comparison with the active phase the DR+CD3+ and DR+CD4+ cells decreased in remission, but DR+CD8+ cells remained unchanged. The decrease in the ratio of CD4+/CD8+ cells was less marked than that of the DR+CD4+/DR+CD8+ cells, which fell into the normal range. Our results suggest an excessive activation of T-helper cells as well as a deficiency in T-suppressor cells which may play an important role in the pathogenesis of Graves' disease.

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.

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.

[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.

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.

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.

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.

Uterine oestrogen-receptor binding to oligo(dT)-cellulose. An inhibitor from hypothalamic cytosol

The binding of rat uterine cytosol oestrogen receptor in vitro to oligo(dT)-cellulose is mediated by an activating factor in the cytosol [Thrower, Hall, Lim & Davison (1976) Biochem. J. 160, 271-280]. A potent inhibitor of this binding is present in hypothalamic cytosol. This inhibitor may have a role in vivo in regulating receptor translocation in the hypothalamus.