Chord-length distribution function for two-phase random media.
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Journal Article↗
Biomedical subjects
B Lu
Publications and source records attributed to B Lu.
A histological study of the eye lesions in 12 leprosy patients with tuberculoid lesion in 4 eyes.
The histological reactions in 12 eyes of 12 leprosy patients were studied (5 BT, 1 BB, 1 BL and 5 LL). Granuloma lesions composed of epithelioid cells, Langerhans giant cells, macrophages and lymphocytes were found in various intraocular tissues, e.g. cornea, sclera, iris, ciliary body or retina in 4 patients (1 BT and 3 LL). Of the 3 LL patients, according to the records, 2 were cured and in the other patient the outcome of the treatment was not mentioned. In view of the finding of the granulomatous lesions in the clinically cured patients and tuberculoid granuloma in the intraocular tissues in the LL patients, could there be some peculiarities in the intraocular sites? Or perhaps the tuberculoid reaction is just a manifestation of an upgrading reaction? More examinations on human leprosy eye specimens will be needed to answer these questions.
Adult↗
[Study on compound levonorgestrel microspheres].
Levonorgestrel (LNG) and estradiol (E2) were mixed in the ratio of 5:2 by weight. Compound LNG gelatin-microspheres were prepared by phase-separation method, natural biodegradable gelatin being used as the core material. The experimental conditions were optimized, the mean diameter of the microspheres obtained being 10-40 microns, and the rate of encapsulation 65-75%. Storage observations and acceleration tests of the compound LNG gelatin-microsphere injection prepared showed that the microspheres have good stability. The thermal degradation activation energy of the injection was determined to be 134.4 kJ/mol, based on differential scanning colorimetry (DSC). T1/2 values for dissolution in vitro of LNG and E2 from the compound LNG gelatin-microsphere injection and from the unencapsulated injection showed significant difference (P < 0.01), indicating that the microspheres have good sustained release action. Effects of the pure LNG microsphere injection and compound LNG microsphere injection on the mouse ovary were compared histologically. The results showed that the compound LNG microsphere injection reduced some of the side effects such as ovary congestion. This points out that the compound dosage form can clinically alleviate the irregular bleeding caused by the administration of LNG alone.
Animals↗
[Studies on preparation technology of microspheres of contraceptives].
Contraceptive poly ethylglycol-lactide (PEGL), an artificial biodegradable polymer microsphere was prepared by a solvent evaporation process using levonorgestrel (LNG) and estradiol (E2) as model drugs and PEGL as the core material. The experimental conditions were optimized, the mean volume diameter obtained being 30 microns and rate of encapsulation 75-82%. In vitro, it was found that the drug release rate decreased with decreasing drug content in the microspheres. The microspheres of the contraceptive maintained anticonception duration in mice for over 6 months, indicating that the microspheres have remarkably long acting sustained release action.
Animals↗
[Testicular tissue homotransplantation of newborn rat: experimental study].
32 newborn Sprague-Dawley rats were used as donors and 32 castrated male out-bred mature rats as recipients. The pieces of testes tissue were implanted subcutaneously in the bilateral hind legs. Two month follow-up showed that the grafts survived and increased in size. Serum testosterone levels of the recipients were higher than those of the castrated. They peaked and were close to the levels of the mature rats even 45 days after the implantation. Serum FSH, and, LH levels in the recipients were lower than those of the castrated. The mechanism of the newborn testes as an immuno-privileged donor is discussed.
Animals↗
A single nuclear gene specifies the abundance and extent of RNA editing of a plant mitochondrial transcript.
A number of cytosines are altered to be recognized as uridines in transcripts of the NADH-dehydrogenase subunit 3 (nad3) gene in the mitochondria of the higher plant Petunia hybrida. Here we show that the extent of editing for three of the edit sites, all of which change the encoded amino acid, varies between different Petunia lines. Genetic analysis indicates that a single nuclear gene is responsible for this variation. Interestingly, according to RNA blot hybridization analysis, RNA editing extent and transcript abundance are correlated. This observation is consistent with the hypothesis that RNA editing is a post-transcriptional event.
Base Sequence↗
Calcium-dependent transmitter secretion reconstituted in Xenopus oocytes: requirement for synaptophysin.
Calcium-dependent glutamate secretion was reconstituted in Xenopus oocytes by injecting the oocyte with total rat cerebellar messenger RNA (mRNA). Co-injection of total mRNA with antisense oligonucleotides to synaptophysin message decreased the expression of synaptophysin in the oocyte and reduced the calcium-dependent secretion. A similar effect on secretion was observed for oocytes injected with total mRNA together with an antibody to rat synaptophysin. These results indicate that synaptophysin is necessary for transmitter secretion and that the oocyte expression system may be useful for dissecting the molecular events associated with the secretory process.
Animals↗
Lineal-path function for random heterogeneous materials. II. Effect of polydispersivity.
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Journal Article↗
Nearest-surface distribution functions for polydispersed particle systems.
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Journal Article↗
Lineal-path function for random heterogeneous materials.
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Journal Article↗
Exogenous synapsin I promotes functional maturation of developing neuromuscular synapses.
We have investigated the possible role of synapsin I, a nerve terminal-specific protein, in the maturation of neuromuscular synapses in Xenopus cell cultures. Purified synapsin I was loaded into embryonic spinal neurons by injection of the protein into one of the early blastomeres of a Xenopus embryo. At synapses made by synapsin I-loaded neurons, spontaneous synaptic currents occurred with higher frequency and amplitude, and the amplitude exhibited an earlier appearance of a bell-shaped distribution. These characteristics are indicative of more mature quantal secretion. Impulse-evoked synaptic currents also showed a significant increase in amplitude. Using cell manipulation techniques, enhanced transmitter release from synapsin I-loaded neurons was shown to occur at the onset of synaptogenesis, suggesting a presynaptic developmental action of synapsin I prior to synaptic contact. Taken together, these results suggest that endogenous synapsin I may participate in the functional maturation of synapses.
Acetylcholine↗
Separation of glucuronides from urine by coupled-column separation using underivatized silica as precolumn.
Glucuronides are separated from urine by coupled-column separations (CCSs). The fraction containing the glucuronide(s) is transferred on-line from a silica precolumn to the analytical column (octadecyl derivatized silica), enriched, and separated by ion-pair chromatography. The retention and selectivity on the precolumn are controlled by pH, buffer components, organic modifier, and ion-pair agent. After the injection of filtered urine samples, glucuronides with different chemical properties can be separated. The total analysis of morphine-3-glucuronide and morphine-6-glucuronide is accomplished in less than six minutes, with UV detection at 210 nm.
Buffers↗
Cell-type-specific localization of transforming growth factor-beta 2 and transforming growth factor-beta 1 in the hamster ovary: differential regulation by follicle-stimulating hormone and luteinizing hormone.
Cell-type-specific localization and gonadotropin regulation of transforming growth factor-beta 1 (TGF-beta 1) and transforming growth factor-beta 2 (TGF-beta 2) in the hamster ovary were evaluated immunohistochemically under three conditions: (1) during the estrous cycle (Day 1 = estrus; Day 4 = proestrus); (2) after the blockade of periovulatory gonadotropin surges by phenobarbital, and (3) after FSH and/or LH treatment of long-term hypophysectomized hamsters. Ovarian TGF-beta 1 activity was primarily localized in theca and interstitial cells. The activity increased moderately but significantly after the preovulatory LH surge and reached a peak at 0900 h, Day 2 h; oocytes showed considerable activity. TGF-beta 1 immunoreactivity subsequently fell to low levels in theca-interstitial cells through 0900 h, Day 4. Significant TGF-beta 2 immunoreactivity appeared after the surge, mainly in the granulosa cells of both preantral and antral follicles; a few interstitial cells surrounding preantral follicles showed discrete staining. TGF-beta 2 immunoreactivity in granulosa cells and in interstitial cells next to preantral follicles reached a peak at 0900 h, Day 1, and persisted up to 0900 h, Day 2; oocytes showed no staining. Phenobarbital treatment blocked the appearance of TGF-beta 1 and TGF-beta 2 immunoreactivities at 1600 h, Day 4; however, a rebound in immunoreactivities was observed with the onset of the surge after a 1-day delay. Replacement of LH to long-term hypophysectomized hamsters resulted in a marked increase in TGF-beta 1 immunoreactivity in the interstitial cells, but FSH, although it induced follicular development, did not influence ovarian TGF-beta 1 activity. Treatment with FSH, however, induced a massive increase in TGF-beta 2 immunoreactivity in the granulosa cells of newly developed antral and preantral follicles but not in the interstitial cells; LH, on the other hand, had no significant effect on TGF-beta 2 activity. Treatment with FSH and LH combined resulted in a dramatic increase in TGF-beta 2 immunoreactivity in granulosa and interstitial cells and in TGF-beta 1 in theca and interstitial cells comparable to their peak activity in intact animals. Western analyses substantiated the presence of TGF-beta 1 and TGF-beta 2 in the hamster ovary and the specificity of immunolocalization. These studies, therefore, provide critical evidence that TGF-beta 1 and TGF-beta 2 in the hamster ovary are expressed in specific cell types and that their expression is differentially regulated by LH and FSH, respectively.
Animals↗
Short-term reproducibility over time of right ventricular pulse pressure as a potential hemodynamic sensor for ventricular tachyarrhythmias.
The implantable cardioverter defibrillator (ICD) has been shown to effectively terminate episodes of ventricular tachyarrhythmias. Multiple investigators have suggested that the incorporation of hemodynamic sensors may allow ICDs to differentiate between hemodynamically unstable and stable ventricular tachyarrhythmias (VT), as well as differentiate ventricular from supraventricular tachycardias. Right ventricular (RV) pulse pressure has been shown to possess acceptable characteristics as a sensor for incorporation in ICDs. We sought to determine the short-term reproducibility of RV pulse pressure measurements by comparing RV pulse pressure measured during two separate episodes of VT in each of ten study patients. The mean VT cycle length for VT episode 1 was 293 +/- 15 msec, and was 298 +/- 15 msec for VT episode 2 (P = NS). The decrease in mean arterial pressure was 40 +/- 7 mmHg in episode 1 and 37 +/- 7 mmHg in episode 2 (P = NS). The decrease in RV pulse pressure during episode 1 was -13 +/- 2 mmHg, and -12 +/- 2 during episode 2 (P = NS). The decrease in RV pulse pressure during episodes of VT at two different times during a single electrophysiology study is highly reproducible, suggesting that RV pulse pressure may be a reliable sensor over time.
Aged↗
[Squamous metaplasia of the mucosa of the human laryngeal ventricle: a clinicopathological study with reference to the possibility of de novo carcinogenesis].
Primary carcinomas are rarely encountered in the laryngeal ventricle of Morgagni. They are classified into the subgroup of supraglottic laryngeal carcinoma in the TNM classification system of malignant tumors. However, detailed investigations have not hitherto been made on the possible occurrence of carcinomas in this region of the larynx. To find out whether the laryngeal ventricle could be the site of carcinogenesis, the author examined squamous metaplasia in the mucosal epithelium of 60 human laryngeal ventricles which were taken from 38 larynges removed operatively from patients with laryngeal carcinoma (14 cases), hypopharyngeal carcinoma (20 cases), carcinoma of the upper esophagus (two cases), tracheal carcinoma (one case) or thyroid carcinoma (one case). The patients consisted of 31 males and 7 females, with an age distribution of 44 to 80, average 62.7. The laryngeal ventricles were selected for investigation only when they did not show any carcinomatous invasion macroscopically. Macroscopic observations were performed after gross staining with pyronin Y, which permits differentiation of squamous metaplasia from respiratory epithelia. Tissues were embedded in paraffin, sectioned serially and stained with hematoxylin and eosin. The clinical records of the patients were also made. The results are summarized as follows: 1. Squamous metaplasia of the stratified ciliated epithelium was found in 38 out of 60 specimens (63%) of the laryngeal ventricles examined. 2. The metaplasia seemed to be precipitated by smoking or exposure to radiation, along with aging. 3. The incidence and extent of metaplasia of the ventricular mucosa depended on the disease entity which had necessitated total laryngectomy, and the metaplasia was most prominent in cases with the supraglottic type of laryngeal carcinoma. 4. The metaplastic epithelium was occasionally associated with hyperplasia or dysplasia of the epithelium. 5. Microinvasive carcinoma was found in one laryngeal ventricle with severe metaplasia. These findings suggested a possible de novo carcinogenic process in the laryngeal ventricle through squamous metaplasia of the respiratory epithelium. From this observation, the author proposes to call carcinoma of this region of the larynx the ventricular type of laryngeal carcinoma.
Adult↗
[Changes in excitatory amino acids and N-methyl-D-aspartate receptors in the brain in aged mice].
By means of chromatography and radioligand binding assay, changes of excitatory amino acids (EAA) and N-methyl-D-aspartate(NMDA)receptors in the cerebral cortex of aged mice were investigated. It has been demonstrated that the maximal binding capacity (Bmax) of NMDA-sensitive 3H-L-glutamic acid (3H-L-Glu) in the cerebral cortex of aged mice (14 months) was obviously decreased as compared with that of young mice (2 months), but no significant differences in KD values between young and aged mice were observed. The content of L-Glu in the cerebral cortex of aged mice was reduced 18.7% when compared with that of young mice. However, no change in the content of L-aspartic acid was found. Long-term potentiation (LTP) of synaptic transmissions in the hippocampus is mediated by NMDA receptors. We also confirmed that the slope and amplitude of hippocampal population spikes were significantly lower in aged mice than in young mice after induction of LTP by tetanus (100 Hz, ls), and persistent time of LTP in aged mice was shorter as compared with that in young mice. The results showed that the functions of the central EAA neurotransmitter systems are decreased, and such changes may be related to the decline of learning and memory capacities in the aged.
Action Potentials↗
[Study on pilules of indomethacin--PEG 6000].
Indomethacin (IDM)-PEG 6000 pilules were prepared using PEG 6000 as the carrier. The solubility of IDM in IDM-PEG 6000 pilules was about twice as much as pure IDM. When the effective dose of IDM-PEG 6000 was only half that of IDM tablet, the irritation of IDM-PEG 6000 pilule on rat stomach was reduced significantly but it still manifested the action of inhibiting the secretion of basal gastric acid.
Animals↗
[Dissolution rate and bioavailability of famotidine tablets].
An automated dissolution test system was used for the determination of the dissolution rate of famotidine tablets, and a mean cumulative dissolution rate of 97.40 +/- 0.31% in 15 min was obtained. To each of six healthy volunteers, 40 mg of famotidine tablets were administered orally, then an automated HPLC with switching column system was used to analyze famotidine in plasma. Variation of drug concentration vs time were fitted to curves. By comparison of calculated values with observed ones, the results could be described as one-compartment model in human. According to a statistic moment algorithm, the results of calculation showed that T1/2 = 2.92 h and Frel = 118.8%.
Biological Availability↗