[Image-analysis of salivary tumors]

The image analysis of 49 cases of salivary tumors showed that the cellular DNA content of most tumors (42/49) was diploidy and near diploidy. The heteroploidy rate was only 14.29% (7/49), which may be related to such clinical behaviors of salivary tumors as slow growth, relative low invasivity and metastatic ability. Among these morphologic parameters, nuclear perim and form PE were closely correlated with the malignancy of salivary tumors, the former was positive and the latter was negative. The insignificant nuclear heteromorphous appearance of adenoid cystic carcinoma and its relatively high cellular DNA content may be related to strong invasivity and metastatic ability. In conclusion, these parameters of DNA content and nuclear morphology supplied by image analysis are of value in the diagnosis of salivary tumors.

Preparation and evaluation of oral dosage form using acylglycerols. II. Effect of food ingestion on dissolution and absorption of aspirin from the granules prepared by acylglycerols in human subjects

The dissolution behavior of the aspirin enteric granule prepared using acylglycerols, glyceryl monostearate (GMS) and glyceryl trilaurate (GTL), was investigated in vitro and in human subjects in a fasting or non-fasting state. Aspirin was slowly released from the granule in vitro at pH 1.2. No acceleration of the aspirin dissolution rate in the medium without lipase and cholic acid was observed when the pH level of the medium increased to a neutral region (pH 6.4). However, the dissolution of aspirin was significantly increased by increasing the concentrations of lipase and cholic acid in the medium. Lipase appears to play an essential role in the dissolution process of aspirin granules. In human subjects, the average levels of the cumulative amount of total salicylate excreted in a urine-time curve, and the mean residence time (MRT) obtained after oral administration of a granule in the fasting state were markedly delayed in comparison with the results observed using an aqueous solution and a crystalline form of aspirin. In comparing the fasting condition with the non-fasting condition (after food ingestion), no significant difference was recognized in the total amount of salicylate excreted in urine to an infinite time (Ae(infinity)), whether the MRT was obtained by granule, crystalline form or aqueous solution. It can be concluded that aspirin granule prepared by GMS and GTL has a property of pancreatic lipase-sensitive dissolution, and its bioavailability is unaffected by food intake.

Development of Diapiric Structures in the Upper Mantle Due to Phase Transitions

Solid-state phase transitions in time-dependent mantle convection can induce diapiric flows in the upper mantle. When a deep mantle plume rises toward phase boundaries in the upper mantle, the changes in the local thermal buoyancy, local heat capacity, and latent heat associated with the phase change at a depth of 670 kilometers tend to pinch off the plume head from the feeding stem and form a diapir. This mechanism may explain episodic hot spot volcanism. The nature of the multiple phase boundaries at the boundary between the upper and lower mantle may control the fate of deep mantle plumes, allowing hot plumes to go through and retarding the tepid ones.

[A study of the regulatory role of GABA on the LHRH release in the median eminence of rats]

The present study was undertaken to observe the effect of GABA and NA on LHRH neuronal terminals in the median eminence (ME). The results showed that GABA (10(-6) mol/L) significantly increased LHRH and NA release from ME, i.e., respectively from 27.3 +/- 2.5 pg/100 microliters to 150.4 +/- 27.9 pg/100 microliters and from 50.9 +/- 4.2 pg/100 microliters to 105.5 +/- 19.1 pg/100 microliters (both P less than 0.01 vs control group). These effects of GABA could be blocked by bicuculline. When bicuculline and GABA (10(-6) mol/L) were added into the ME, the secretion of LHRH decreased to 18.2 +/- 1.9 pg/100 microliters and that of NA to 43.9 +/- 3.4 pg/100 microliters. The effect of GABA on LHRH release may be mediated by NA. When endogenous NA was depleted by reserpine, GABA increased LHRH secretion only by 26.5% instead of 451.9% as in the normal animal.

Molecular mechanisms of memory formation

Studies with neonate chicks, trained on a passive avoidance task, suggest that at least two shorter-term memory stages precede long-term, protein synthesis-dependent memory consolidation. Posttetanic neuronal hyperpolarization arising from two distinct mechanisms is postulated to underlie formation of these two early memory stages. Maintenance of the second of these stages may involve a prolonged period of hyperpolarization brought about by phosphorylation of particular proteins. A triggering mechanism for long-term consolidation is postulated to occur at a specific time during the second stage, and may involve reinforcement-contingent release of neuronal noradrenaline stimulating cAMP-dependent intracellular processes. The possibility that astroglia may have a critical role to play in these early stages of memory processing is raised.

Analgesia produced by pituitary ACTH and dopaminergic transmission in the arcuate

Analgesia (NAA) caused by nonacupuncture point (abdominal muscle) stimulation after lesioning the analgesia inhibitory system (AIS) or treating the subject with proglumide was abolished by hypophysectomy or adrenalectomy. The final sector of the NAA afferent pathway from the nonacupuncture point to the pituitary gland and the initial sector of the descending pain inhibitory system were found in the anterior and posterior arcuate nucleus (A-HARN and P-HARN), respectively. Analgesia caused by ACTH microinjected into the P-HARN disappeared after denervation of the A-HARN, but that caused by dopamine did not. Firing rates of P-HARN neurons were increased by nonacupuncture point simulation (NAPS) after lesion of the AIS or treatment with proglumide. The NAPS responsive neurons also responded to ultramicroinjected dopamine, but not to ultramicroinjected ACTH. Both NAA and NAPS responsive neuron activity that were abolished by hypophysectomy were restored by concurrent application of NAPS and intraperitoneal ACTH. Reduction of sodium ions due to adrenalectomy was found to abolish NAA. It was concluded that NAA production involves dopaminergic transmission in the HARN and ACTH acting presynaptically on this transmission.

[Deleterious effects of calcium on the pathogenesis of ischemic brain damage]

Using atomic absorption spectroscopy, we measured the regional distribution of tissue Ca++ contents of 24 rabbit brains sampled at 2,4,24 and 48 hours after the occlusion of Middle Cerebral Artery (MCAo) with accompanying histopathological examinations with 10 controls. At 2 hours after MCAo, brain tissue Ca++ concentration increased significantly (P less than 0.005) in the ischemic territory and increased further with times, far preceding the detectable pathological findings termed necrosis, which appeared at 12 hours after MCAo. It seems most probable that the deleterious effects of calcium play an important role in the pathogenesis of ischemic brain damage.

[Observation for 3 years on the immune effects of hepatitis B vaccine in susceptible population]

Chinese-produced HB vaccine induced high levels of antibodies against HB surface antigen in susceptible population (babies born to mothers who were negative for HBsAg and people who were negative for all the HBV markers). Eight months after the first dose, 97.73 and 93.75 percent of the neonates who received 10 micrograms (group I) and 20 micrograms (group II) vaccines and 92.45 percent of the adults who received 20 micrograms vaccine (group III) developed anti-HBs with the S/N values of 42.12, 46.53 and 36.20, and gave effective protection rates (S/N greater than or equal to 10) of 86.36%, 89.58% and 79.25%, respectively. No significant difference was noted between these groups. After three years, the positive rates and the S/N values of anti-HBs were 17.1% and 3.70 in group I, 15.6% and 4.23 in group II, 20.4% and 4.04 in group III respectively. One month after booster injection in anti-HBs, the S/N values of anti-HBs were 85.12 in group I with 10 micrograms vaccine, 89.23 in group II with 30 micrograms vaccine and 90.82 in those aged 4-10 years with 10 micrograms vaccine. The infection rate in the neonates who were not vaccinated with HB vaccines (11.11%) was higher than those who were vaccinated (0%). So it is clear that Chinese-produced HB vaccines are safe and effective.

[Effects of alcohol extract from Polygonatum odoratum (Mill.) Druce and Cuscuta australis R. Br. on immunological function of mice injured by burns]

This paper shows that the alcoholic extract from Polygonatum odoratum and Cuscuta australis increases the percentage of phagocytosis and the index of phagocytosis of macrophages as well as hemolysin and proliferation of lymphocytes up to normal level in mice with II+ burn injury covering 5% body surface. It follows that both Polygonatum odoratum and Cuscuta australis may serve as a kind of immunopotentiator for mammals.

Generation of dark solitons under a cw background using waveguide electro-optic modulators

We propose a novel method for generating dark solitons with a cw background by using broadband guided-wave electro-optic modulators. The generated pulse can be amplified by stimulated Raman scattering to permit the observation of soliton effects in the fiber.

Hb Hekinan observed in three Chinese from Macau; identification of the GAG----GAT mutation in the alpha 1-globin gene

Hb Hekinan, an alpha chain variant that is characterized by a Glu----Asp mutation at position alpha 27, was observed in three Chinese females attending a prenatal clinic in Macau. The relative quantities of the stable hemoglobin were 13-14% (average 13.3%); its identification was greatly aided by the separation and purification of the peptides by reversed phase high performance liquid chromatography. Dot-blot analysis of amplified DNA with 32P-labeled probes located the mutation in codon 27 of the minor alpha 1-globin gene; the change involved a GAG (coding for glutamic acid) to GAT (coding for aspartic acid) mutation.

Interactions between dark solitons

The interaction forces between two dark solitons are numerically investigated. It is found that dark solitons are less affected than bright solitons by their respective interaction forces. An empirical expression for the separation of two solitons as a function of initial separation and traveling distance is deduced, which agrees well with numerical results.

Periodic amplification of dark solitons using stimulated Raman scattering

The possibility of periodically amplifying dark solitons in a normally dispersive optical fiber is studied. It is found that, as with bright solitons, an all-optical, repeaterless, and stable system for dark-soliton transmission at a rate of 20 GHz over thousands of kilometers in a lossy fiber is achievable, if periodic amplification using stimulated Raman scattering is incorporated.

Propagation properties of dark solitons

We numerically study the initial-value problem of the nonlinear Schrödinger equation in the normal-dispersion regime of an optical fiber. A nonchirped hyperbolic tangent input pulse having arbitrary amplitude is found to evolve into a primary dark soliton having a constant amplitude and speed. The effect of the input amplitude is to alter the pulse width of the primary dark soliton. In addition, a set of secondary dark solitons of smaller amplitude moving away from the primary pulse is also generated. It is also shown that nonlinear dark pulses in optical fibers are more stable than bright pulses with respect to loss and noise.