复合多糖稳定剂在乳白鱼肝油中的应用

采用ＨａａｋｅＲＶ１２粘度仪测定复配胶溶液、７７９６胶溶液以及乳白鱼肝油的流变性质，用光散射仪测定乳白鱼肝油中油滴大小分布，结果表明，复配胶与进口的７７９６胶相比，不仅价格低，而且稳定性能优于７７９６胶。使用ＤＬＶＯ理论探讨了复配胶稳定乳白鱼肝油的稳定机理。     

The efficacy of an anti-gingivitis chewing gum

Abstract Chlorhexidine is a well-established agent used for the control of supragingival plaque but is not without disadvantages, such as tooth staining, which limits its clinical applications to short-term use. This clinical trial studied the clinical effectiveness and stain-forming potential of chlorhexidine in a chewing gum base. Subjects (151) were screened for baseline plaque and gingival indices before receiving a dental prophylaxis and randomized into 3 treatment groups: group 1 chewed 2 pieces of chlorhexidine diacetate gum for 10 min 2× a day (total daily chlorhexidine=20 mg). group 2 chewed 2 pieces of placebo gum for 10 min 2× a day and group 3 rinsed with 10 ml of 0.2% chlorhexidine gluconate mouthwash for 1 min 2× per day (total daily chlorhexidine=40 mg). Plaque, gingivitis and stain evaluations were made at 4 and 8 weeks. Plaque and bleeding scores were significantly lower at 4 and 8 weeks in the chlorhexidine gum group compared to the placebo gum group and similar at 8 weeks to the rinse group. Stain intensity at week 8 was significantly less for the chlorhexidine gum than rinse. The staining measured by extent was also Jess with the chlorhexidine gum than the rinse, but the difference was not significant at week 4. At week 8, stain extent was significantly lower in the chlorhexidine gum group than chlorhexidine rinse. In conclusion, the results of this study demonstrate that this chlorhexidine chewing gum used with normal tooth cleaning provides similar adjunctive benefits to oral hygiene and gingival health as a 0.2% chlorhexidine rinse.     

The induction of grooming and vacuous chewing by a series of selective D-1 dopamine receptor agonists: two directions of D-1:D-2 interaction

A range of 3- and 6-substituted 1-phenyl-1H-3-benzazepine analogues of SK & F 38393 with D-1 agonist activity were compared for their behavioural effects in the intact adult rat and for their relative affinities for D-1 and D-2 dopamine receptors in vitro. All compounds showed selective affinity for D-1 receptors and induced prominent grooming behaviour, but those with the lower D-1: D-2 selectivity ratios also induced additional episodes of non-stereotyped sniffing, locomotion and rearing. No vacuous chewing was noted. There were marked differences in in vivo potency, extending over a 100-fold range. These responses to the most potent agonist, SK & F 77434 (3N-allyl-SK & F 38393) were reduced enantioselectively by the D-1 antagonist R-SK & F 83566. They were also reduced enantioselectively by the D-2 antagonist R-piquindone, but this pretreatment additionally released a marked vacuous chewing response to SK & F 77434. Prominent grooming may be a characteristic behavioural response to a range of D-1 agonists. It is suggested that there may be at least two forms of functional interaction between D-1 and D-2 systems, manifested concurrently in distinct elements of behaviour: one co-operative, as in the regulation of grooming, and with correlates in the regulation of pallidal neural activity; the other oppositional, as in the regulation of vacuous chewing, and with correlates in the regulation of striatal adenylate cyclase activity.     

The effect of caffeine on the ability of spermatozoa to fertilize mature human oocytes

Although caffeine has been reported to enhance spermatozoon motility as well as fertilizing ability, its use in clinical practice has remained sparse. We report here the results carried out to assess the effect of exposing normal human spermatozoa to different concentrations of caffeine on their motility, their ability to fertilize oocytes, and the subsequent development of resulting embryos. Mature human oocytes were inseminated with spermatozoa washed and capacitated in 1.25, 2.5, and 5 mMcaffeine. The fertilization rates were compared with control oocytes inseminated with untreated spermatozoa. While caffeine was observed to improve significantly various motility parameters in a dose-dependent manner, it did not lead to an improvement in the fertilization rates. At the highest concentration, 5 mM,it adversely affected the fertilization rate: 38%, compared with 78% in controls. Embryonic development was also observed to be retarded at the lower concentrations, while it was virtually inhibited in the 5 mM concentration group. Our results suggest that while a definite improvement in motility may occur when spermatozoa are exposed to caffeine, this improvement did not translate into enhanced fertilizing ability and subsequent embryonic development. We are therefore of the opinion that the use of caffeine as a spermatozoon motility enhancer requires further studies prior to wider clinical use in assisted pregnancy programs.     

Structural alterations in Candida albicans by caffeine and caffeine salts

Cytological alterations of Candida albicans following exposure to subinhibitory concentrations of caffeine and caffeine salts were examined by light and transmission electron microscopy (TEM). The effect was different from that induced by ketoconazole. Caffeine and especially caffeine salts caused an increase in unusual modes of proliferation with signs of multiple budding in Candida albicans. Structurally, such yeast cells present some resemblance to Paracoccidioides brasiliensis.     

正交函数分光光度法与吸收度减法联用技术测定咳喘感冒片中咖啡因的含量

采用正交函数分光光度法与吸收度减法联用技术测定咳喘感冒片中咖啡因的含量，平均回收率为９９．４％，变异系数（ＣＶ％）为０．９５％，（ｎ＝６），相关系数（ｒ）为０．９９９４。     

Regulation of nitric oxide synthase activity in cortical slices by excitatory amino acids and calcium

Nitric oxide synthase (NOS) activity was determined in adult rat frontal cortex and hippocampus by measuring the conversion of L-[³H]arginine to L-[³H]citrulline. N-methyl-D-aspartate (NMDA), but not kainate or α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA), stimulated NOS activity. This effect was concentration dependent (EC₅₀ ≈ 30μM) and was inhibited by tetrodotoxin, EGTA, N^ω-nitro-L-arginine (NOARG), Mg²⁺, phencyclidine, and (cis)-4-phosphonomethyl-2-piperidine carboxylate (CGS 19755), but not by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). NOS activity was increased to an even greater extent by the calcium ionophores ionomycin and A23187 and by depolarization with 50 mM K⁺. Interestingly, neither caffeine nor 1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD), drugs that would be expected to increase intracellular Ca²⁺ concentration by release of Ca²⁺ from intracellular ryanodine- and inositol-1,4,5-trisphosphate-sensitive stores, respectively, had any significant effect on NOS activity. It is concluded that NOS can be activated by NMDA binding to a classic NMDA glutamate receptor subtype as well as by depolarization or other agents that increase the influx of extracellular Ca²⁺. The paradoxical lack of effect of caffeine, as well as the inhibitory effect of tetrodotoxin, are discussed. © 1994 Wiley-Liss, Inc.     

黄原胶对蛋白酶耐热性的作用

黄原胶对１．３９８中性蛋白酶的热稳定性有一定的保护作用，使含０．４％黄原胶的酶液在５５℃处理２０ｍｉｎ后残留酶活达５０％以上，而对照酶则几乎完全失活     

A plaque index for occlusal surfaces and fissures

Abstract. Plaque indices have largely been developed for buccal and lingual tooth surfaces. There has been minimal interest in plaque accumulation on occlusal surfaces despite the predilection for caries at these sites. A numerical plaque index (0–5) is described based on the presence and distribution of plaque in the fissures and over the occlusal surfaces of permanent molar and premolar teeth. The repeatability of a single examiner in scoring the index was performed using 4 groups of 10 subjects. Each group of volunteers suspended tooth cleaning for 48 h and the index scored after disclosing plaque deposits. The index was rescored 60–90 min later. Plaque area was also determined by drawing the outline of plaque onto grids. Except for one condition of repeatability for one group, the 4 conditions of repeatability in scoring the index were met for all 4 groups of subjects. The sensitivity of the index and area recordings to detect plaque removed by brushing was then evaluated. A group of 10 subjects had plaque scored by index and area after suspending toothcleaning for 48 h. Subjects were then randomly allocated to brush or not brush their teeth and plaque rescored. The experiment was then repeated and brushing or not brushing crossed over. Highly significant differences between brushing and no brushing plaque indices and areas were determined. In conclusion, the occlusal fissure plaque index was easy to apply, repeat-able and sufficiently sensitive to detect plaque removed by brushing. The index could find use as an additional measure of oral hygiene, in clinical trials on plaque control and possibly epidemiological studies relating to caries.     

Chewing electric wire coatings: An unusual source of lead poisoning

This report describes a case of lead poisoning occurring in an electrician as the result of an unusual personal habit, namely, the chewing of lead-containing coatings of electric wires. A coating chewing test showed that a few minutes after beginning chewing, saliva lead concentration increased from 10 (μg/l to several milligrams per liter. This case is an example of poisoning caused by an occupationally related source (coatings containing lead) as a consequence of a singular and unconventional worker's habit. © 1994 Wiley-Liss, Inc.