AIMTo study the dissolution rate of solid pharmaceutical preparation on-line, a multiple channel fiber-optic chemical sensor based on fluorescence multiple quenching (FOCSMQ) without filtering and sampling was made.

METHODSUsing the multiple channel FOCSMQ linked with computer, the dissolution rates of ofloxacin tablets, metronidazole tablets and nitrofurantoin tablets were monitored continuously on-line. The instrument can give the sample data, display the real time curve and calculate the T1/2 and td automatically. A computer was used to select the best function from five common fitting models to fit the dissolution curve.

RESULTSThe average recoveries of the FOCSMQ method were 97.4%-104.4%, 97.4%-103.8% and 96.6%-102.1%. The RSDs (n = 6) of within-day and between-day were less than 5%. The parameters of the dissolution and all results of measurement using the instrument have no significant difference compared with the Chinese Pharmacopoeia (ChP) (2000) method and the United States Pharmacopoeia (USP) (23) method (P > 0.05). It does not need sampling and dilution, and never contaminate sample. It can shorten time of the experiment.

CONCLUSIONThe method is simple, rapid and reliable.

Chemistry, Pharmaceutical ; instrumentation ; Fiber Optic Technology ; methods ; Metronidazole ; chemistry ; Nitrofurantoin ; chemistry ; Ofloxacin ; chemistry ; Optical Fibers ; Solubility ; Tablets ; chemistry ; Transducers

OBJECTIVETo explore the characters of lung injury induced by tin dusts and to provide the diagnosis evidence of tin pneumoconiosis.

METHODSForty SD rats were randomly divided into four groups: the group exposed to tin dusts from smelting workshop, the group exposed to tin dusts from tin refining workshop, the positive control group exposed to standard quartz dusts and the negative control group exposed to saline. The pathological changes of rat lungs were observed dynamically.

RESULTSIn rats exposed to tin dusts, on the 30th day after exposure to tin dusts, the scattered hoar tip size of the spots in surface and section of the lungs were observed, the scattered focal granulomatous inflammation around the small bronchi and dust particles in lung tissue were observed under microscope; on the 90th day after exposure to tin dusts, the granulomatous inflammation increase, the fibroblasts proliferation, collagen fibers formation and positive VG staining were found. There were significant differences, as compared with positive or negative controls (P < 0.05). These pathological changes were basically the characters of specific pathological changes in early tin pneumoconiosis.

CONCLUSIONNon-ferrous metal tin dusts can induce the specific lung injury (granuloma formation) in lung tissue of rats exposed to tin dusts, which fulfilled the diagnostic criteria of specific pathological changes in early tin pneumoconiosis.

Animals ; Dust ; Lung ; pathology ; Lung Injury ; chemically induced ; diagnosis ; pathology ; Rats ; Rats, Sprague-Dawley ; Tin ; adverse effects

OBJECTIVE: To observe the clinical effect of moxibustion with deqi on Alzheimer's disease (AD) rats, and evaluate its effect on β-amyloid (Aβ) transport and enzymatic degradation proteins, to explore its molecular mechanism for improving cognitive function. METHODS: Sixty SPF-grade male SD rats were randomly divided into a blank group (8 rats), a sham-operation group (8 rats) and a model establishment group (44 rats). The rats in the model establishment group were injected with Aβ₁-₄₂ at bilateral ventricles to establish AD model. Among the 38 rats with successful model establishment, 8 rats were randomly selected as the model group, and the remaining rats were treated with mild moxibustion at "Dazhui" (GV 14), once a day, 40 min each time, for 28 days. According to whether deqi appeared and the occurrence time of deqi, the rats were divided into a deqi group (12 rats), a delayed deqi group (10 rats) and a non-deqi group (8 rats). After the intervention, the Morris water maze test was applied to evaluate the cognitive function; the HE staining was applied to observe the brain morphology; the Western blot method was applied to measure the protein expression of Aβ and its receptor mediated transport [low-density lipoprotein receptor-related protein (LRP) 1, receptor for advanced glycation end products (RAGE), apolipoprotein E (ApoE)] and enzymatic degradation [neprilysin (NEP), insulin degrading enzyme (IDE), endothelin converting enzyme (ECE)-1 and angiotensin converting enzyme (ACE) 2]. RESULTS: Compared with the sham-operation group, in the model group, the escape latency was prolonged (P<0.01), and the times of platform crossing and the ratio of platform quadrant to total time were reduced (P<0.01); the brain tissue was seriously damaged; the expression of hippocampal Aβ and RAGE was increased (P<0.01), and the expression of hippocampal LRP1, ApoE, NEP, IDE, ECE-1 and ACE2 was decreased (P<0.01). Compared with the model group, the escape latency was shortened in the deqi group (P<0.05, P<0.01), and the escape latency in the delayed deqi group and the non-deqi group was shortened from Day 2 to Day 5 (P<0.05, P<0.01), and the times of platform crossing and the ratio of platform quadrant to total time were increased in the deqi group and the delayed deqi group (P<0.01, P<0.05); the brain damage in each moxibustion group was reduced, which was smallest in the deqi group, followed by the delayed deqi group and the non-deqi group; the expression of Aβ and RAGE was decreased (P<0.01, P<0.05) and the expression of LRP1 and IDE was increased in each moxibustion group (P<0.01, P<0.05); the expression of ApoE was increased in the deqi group and the delayed deqi group (P<0.01, P<0.05); the expression of NEP was increased in deqi group (P<0.05), and the expression of ECE-1 and ACE2 was increased in the deqi group and the delayed deqi group (P<0.05). Compared with the delayed deqi group and the non-deqi group, the escape latency in the deqi group was shortened from Day 3 to Day 5 (P<0.05), and the times of platform crossing and the ratio of platform quadrant to total time were increased (P<0.05, P<0.01). Compared with the non-deqi group, the expression of Aβ was reduced (P<0.05), the expression of LRP1 and ApoE was increased in the deqi group (P<0.05). The expression of NEP in the deqi group was higher than that in the delayed deqi group and the non-deqi group (P<0.05). CONCLUSION Compared with non-deqi, moxibustion with deqi could promote Aβ transport and degradation, thereby reducing Aβ level in the brain and improving cognitive function for AD rats.
Alzheimer Disease/therapy* ; Amyloid beta-Peptides/genetics* ; Angiotensin-Converting Enzyme 2 ; Animals ; Apolipoproteins E/metabolism* ; Hippocampus/metabolism* ; Male ; Moxibustion ; Rats ; Rats, Sprague-Dawley