[Research advances in post-tuberculosis lung disease]

The burden of tuberculosis remains high in China. Although successfully cured of tuberculosis, a large proportion of patients still suffer from post-tuberculosis lung disease (PTLD), causing great harm to individuals and societies. PTLD is a group of heterogeneous disorders that affects airways, lung parenchyma, pleura, and/or pulmonary vasculature. The related etiology and pathogenesis remain unclear, and are likely the result of the interplay between the host immune responses, pathogens, and environmental factors. Advances in prevention and treatment mainly involve adjuvant therapy and pulmonary rehabilitation. Since PTLD patients mostly visit respiratory departments for consultation, it is essential for respiratory physicians to improve the awareness PTLD, and therefore the research progress of PTLD is reviewed.

[Effect of temporomandibular joint disc perforation on expression of type Ⅰ collagen in temporomandibular joint disc cells]

Objective: To investigate the effect of temporomandibular joint (TMJ) disc perforation on expression of type Ⅰ collagen in TMJ disc cells. Methods: The fibroblastic-like cells from the surgical removed TMJ disc tissue (disc perforation or TMJ condyle hyperplasia) were cultured. The cultured cells were identified as fibroblastic-like cells by toluidine blue and immunofluorescence staining. The expression of type Ⅰ collagen was detected with Western blotting and the content of type Ⅰ collagen was examined by enzyme linked immunosorbent assay (ELISA). Results: Fibroblastic-like cells were cultured from TMJ disc cells and the controls. The collagen-Ⅰ and collagen-Ⅱ were positive in both toluidine blue and immunofluorescence staining. In Western blotting, the expression of typeⅠcollagen in cells from joints with disc perforation was lower than that from normal joints. The content of collagen-Ⅰ was (1.62±0.52) μg/L from controls, and (0.85±0.33) μg/L from disc perforation respectively (P=0.0134). Conclusions: The disc cells from TMJ with disc perforation expressed lower type Ⅰ collagen than that from controls, which may be related to the lower content of collagen-Ⅰ in TMJ disc and the formation of TMJ disc perforation.

Molecular characteristics and cloning of two pepper genes AN2 and UPA20

The complete coding sequences (CDSs) of "Yunnan Purple Pepper No.1" (Capsicum annuum L.) AN2 and UPA20 genes were amplified using the reverse transcriptase polymerase chain reaction on the basis of the conserved sequence information of some Solanaceae plants and known highly homologous pepper expressed sequence tags. The nucleotide sequence analysis of these 2 genes revealed that pepper AN2 gene encoded a protein of 263 amino acids that has high homology with the AN2-like protein of 4 species: tobacco, tomato, potato, and petunia. The UPA20 gene encoded a protein of 341 amino acids that has high homology with the proteins of 3 species: tobacco, petunia, and tomato. The tissue expression analysis indicated that the pepper AN2 gene was overexpressed in the pericarp and placenta; moderately in stems, flowers, and seeds; and weakly in the roots, leaves, and pericarp. The pepper UPA20 gene was overexpressed in the flowers and seeds; moderately expressed in the roots and stems; and weakly expressed in the leaves and placenta. Our findings might form the basis for further research on these 2 pepper genes.

Cloning and bioinformatic analysis of full-length novel pepper (Capsicum annuum) genes TAF10 and TAF13

We isolated two TATA-binding protein-associated factor (TAF) genes, TAF10 and TAF13, from pepper (Capsicum annuum). The complete coding sequences were amplified using reverse transcriptase-PCR on the basis of conserved sequence information of eggplant and several other plant species. Nucleotide sequence analysis of these two genes revealed that the pepper TAF10 gene encodes a protein of 103 amino acids that belongs to the TAF10 superfamily. The pepper TAF10 gene was highly expressed in the pericarp and placenta, moderately expressed in the stems, flowers, seeds and leaves, and weakly expressed in roots. The TAF13 gene was found to encode a protein of 130 amino acids that belongs to the TAF13 superfamily. The TAF13 gene was highly expressed in the stems, flowers and pericarp, moderately expressed in the leaves, placenta and seeds, and weakly expressed in roots.

An eligible biological allograft patch in tension-free herniorrhaphy of swine

Current patches made from macromolecular compounds or composix for tension-free herniorrhaphy are still unsatisfactory in biocompatibility. The ideal patch should be a biological patch with good biocompatibility. Herein allograft patches modified by tissue engineering were used in tension-free herniorrhaphy of swines. Tough membrane tissues from swine were modified with patented tissue engineering techniques to develop allograft patches for tension-free herniorrhaphy. Histological, and physical tests of the allograft patch were performed subsequently, which revealed that the allograft patch was sufficient and satisfactory for tension-free herniorrhaphy. The allograft patches were next used in tension-free herniorrhaphy of abdominal external hernia models of swines and compared to polypropylene patches. Serous CD4+, CD8+ T cells, interleukin-1β (IL-1β), and tumor necrosis factor α (TNF-α) were determined preoperatively and postoperatively. Local pathological changes were recorded postoperatively in swines. In vivo application of the allograft patches revealed that there were no significant serous cellular immune responses in swines, and inflammation induced by allograft patches was significantly lower compared to polypropylene patches, the allograft patches gradually degenerated and new collagen fibers appeared. Abdominal external hernias were cured with allograft patches and without relapse. The modified allograft patch with satisfactory biocompatibility was eligible and sufficient in tension-free herniorrhaphy of swine. Clinical trials should be performed for further evaluation of the allograft patch.

Effect of inducing nocturnal serum melatonin concentrations in daytime on sleep, mood, body temperature, and performance

We examined effects of very low doses of melatonin (0.1-10 mg, orally) or placebo, administered at 1145 h, on sleep latency and duration, mood, performance, oral temperature, and changes in serum melatonin levels in 20 healthy male volunteers. A repeated-measure double-blind Latin square design was used. Subjects completed a battery of tests designed to assess mood and performance between 0930 and 1730 h. The sedative-like effects of melatonin were assessed by a simple sleep test: at 1330 h subjects were asked to hold a positive pressure switch in each hand and to relax with eyes closed while reclining in a quiet darkened room. Latency and duration of switch release, indicators of sleep, were measured. Areas under the time-melatonin concentration curve varied in proportion to the different melatonin doses ingested, and the 0.1- and 0.3-mg doses generated peak serum melatonin levels that were within the normal range of nocturnal melatonin levels in untreated people. All melatonin doses tested significantly increased sleep duration, as well as self-reported sleepiness and fatigue, relative to placebo. Moreover, all of the doses significantly decreased sleep-onset latency, oral temperature, and the number of correct responses on the Wilkinson auditory vigilance task. These data indicate that orally administered melatonin can be a highly potent hypnotic agent; they also suggest that the physiological increase in serum melatonin levels, which occurs around 2100 h daily, may constitute a signal initiating normal sleep onset.

Effects of illumination on human nocturnal serum melatonin levels and performance

In humans, exposure to bright light at night suppresses the normal nocturnal elevation in circulating melatonin. Oral administration of pharmacological doses of melatonin during the day, when melatonin levels are normally minimal, induces fatigue. To examine the relationship between illumination, human pineal function, and behavior, we monitored the overnight serum melatonin profiles and behavioral performance of 24 healthy male subjects. On each of three separate occasions subjects participated in 13.5 h (1630-0800 h) testing sessions. Each subject was assigned to an individually illuminated workstation that was maintained throughout the night at an illumination level of approximately 300, 1500, or 3000 lux. Melatonin levels were significantly diminished by light treatment, F(2, 36) = 12.77, p < 0.001, in a dose-dependent manner. Performance on vigilance, reaction time, and other tasks deteriorated throughout the night, consistent with known circadian variations in these parameters, but independent of ambient light intensity and circulating melatonin levels.

Effect of pharmacological daytime doses of melatonin on human mood and performance

Melatonin (10, 20, 40, or 80 mg, PO) or placebo was administered at 1145 hours on five separate occasions to 20 healthy male volunteers and the effects on serum melatonin levels, mood, performance, and oral temperature were monitored. Subjects were studied between 0930 and 1700 hours. A battery of interactive computer tasks designed to assess performance and mood was completed, oral temperature was measured, and blood samples were taken for serum melatonin radioimmunoassay. The areas under the time-melatonin concentration curve (AUC) varied significantly in proportion to the various melatonin doses. Compared with placebo treatment, all melatonin doses significantly decreased oral temperature, number of correct responses in auditory vigilance, response latency in reaction time, and self-reported vigor. Melatonin also increased self-reported fatigue, confusion, and sleepiness.

Melatonin and its precursors in Y79 human retinoblastoma cells: effect of sodium butyrate

We studied the release of melatonin and the production of its precursors, 5-hydroxytryptophan and serotonin, in cultured Y79 human retinoblastoma cells. This biosynthetic capability was found to be dependent on cell differentiation, which was initiated by culturing Y79 cells for 7 days in dishes coated with poly-D-lysine to promote cell adhesion to the surface of the culture dishes. Differentiation was further induced by exposing the cell monolayer to sodium butyrate (3 mM) for 3 days. This protocol dramatically increased the release of melatonin and the syntheses of 5-hydroxytryptophan and serotonin in response to forskolin stimulation. Exposure to dopamine (10 microM) or L-DOPA (100 microM) markedly diminished the forskolin-stimulated release of melatonin, as well as the production of 5-hydroxytryptophan and serotonin. These observations indicate that Y79 cells represent a primitive cell line which, following appropriate differentiation (e.g. treatment with sodium butyrate) can display biochemical characteristics similar to those of the human retina. Moreover, serotonin synthesis and melatonin release appear to be coupled in Y79 cells. The inhibition of melatonin release by dopamine supports the hypothesis that in these cells, melatonin and dopamine are components of a retinal feedback loop.

Melatonin concentrations in the sudden infant death syndrome

To examine a possible relationship between pineal function and the sudden infant death syndrome (SIDS), samples of whole blood, ventricular cerebrospinal fluid (CSF) and/or vitreous humor (VH) were obtained at autopsy from 68 infants (45 male, 23 female) whose deaths were attributed to either SIDS (n = 32, 0.5-5.0 months of age; mean +/- S.E.M., 2.6 +/- 0.2 months) or other causes (non-SIDS, n = 36, 0.3-8.0 months of age 4.3 +/- 0.3 months). The melatonin concentrations were measured by radioimmunoassay. A significant correlation was observed for melatonin levels in different body fluids from the same individual. After adjusting for age differences, CSF melatonin levels were significantly lower among the SIDS infants (91 +/- 29 pmol/l; n = 32) than among those dying of other causes (180 +/- 27; n = 35, P less than 0.05). A similar, but non-significant trend was also noted in blood (97 +/- 23, n = 30 vs. 144 +/- 22 pmol/l, n = 33) and vitreous humor (68 +/- 21, n = 10 vs. 81 +/- 17 pmol/l, n = 15). These differences do not appear to be explainable in terms of the interval between death and autopsy, gender, premortem infection or therapeutic measures instituted prior to death. Diminished melatonin production may be characteristic of SIDS and could represent an impairment in the maturation of physiologic circadian organization.

The circadian rhythm of plasma melatonin during the normal menstrual cycle and in amenorrheic women

Plasma melatonin, PRL, and LH levels were measured in samples collected every 2 h for 24 h from 14 normally cycling women during the early follicular, periovulatory, and luteal phases of their menstrual cycles. Plasma melatonin levels also were measured in samples collected at the same interval from 7 patients with hypothalamic amenorrhea. A distinct daily rhythm in plasma melatonin was evident in all subjects, with peaks occurring around 0300 h. Each woman's rhythm was remarkably consistent throughout the menstrual cycle (in terms of the phase, amplitude, and total melatonin secreted). Plasma PRL levels also exhibited daily rhythms which did not change during the menstrual cycle; the nocturnal peak plasma PRL level tended to occur 1-2 h after that for melatonin. Among the amenorrheic women, both daytime and nighttime melatonin levels were significantly higher (P less than 0.005) than in the normal women. Their plasma PRL levels were similar to those in the normal women. We conclude that, as for PRL, the circadian rhythm of melatonin secretion does not change significantly during the normal menstrual cycle. The elevated plasma melatonin levels in women with hypothalamic amenorrhea suggest that the hormone may be involved in the neuroendocrine pathology underlying this disorder.

Melatonin in human preovulatory follicular fluid

Melatonin, the major hormone of the pineal gland, has antigonadotrophic activity in many mammals and may also be involved in human reproduction. Melatonin suppresses steroidogenesis by ovarian granulosa and luteal cells in vitro. To determine if melatonin is present in the human ovary, preovulatory follicular fluids (n = 32) from 15 women were assayed for melatonin by RIA after solvent extraction. The fluids were obtained by laparoscopy or sonographically controlled follicular puncture from infertile women undergoing in vitro fertilization and embryo transfer. All patients had received clomiphene citrate, human menopausal gonadotropin, and hCH to stimulate follicle formation. Blood samples were obtained by venipuncture 30 min or less after follicular aspiration. All of the follicular fluids contained melatonin, in concentrations [36.5 +/- 4.8 (+/- SEM) pg/mL] substantially higher than those in the corresponding serum (10.0 +/- 1.4 pg/mL). A positive correlation was found between follicular fluid and serum melatonin levels in each woman (r = 0.770; P less than 0.001). These observations indicate that preovulatory follicles contain substantial amounts of melatonin that may affect ovarian steroidogenesis.

Plasma and pineal melatonin levels in female ferrets housed under long or short photoperiods

Ovohysterectomized female ferrets were housed in controlled environment rooms in which the daily lighting schedule was either 15L:9D (long days) or 9L:15D (short days). After 2 weeks some ferrets in each group were given an intrajugular catheter: beginning 1 week later, a blood sample was taken daily at one of eight different clock times over an 8 to 10 day period. One additional blood sample plus the pineal gland were collected from these animals and from uncathetarized animals in each group after decapitation at different clock times. Both plasma melatonin concentrations and pineal melatonin content were elevated in a square-wave pattern during the dark hours, with the duration of elevation being longer in ferrets kept under the short days. These results suggest that differences in the duration of nocturnal increments in melatonin secretion may mediate the stimulatory and inhibitory effects of long and short days, respectively, on ovarian activity in female ferrets.

Bioavailability of oral melatonin in humans

We administered crystalline melatonin (80 mg) in gelatin capsules to 5 young male volunteers and measured serum and urinary melatonin levels at intervals. Changes in serum melatonin levels were best described by a biexponential equation with an absorption constant (ka) of 1.72 h-1 (half-life = 0.40 h) and an elimination constant (ke1) of 0.87 h-1 (half-life = 0.80 h). Peak serum melatonin levels, ranging from 350 to 10,000 times those occurring physiologically at nighttime, were observed 60-150 min after its administration, remaining stable for approximately 1.5 h. The fraction of ingested melatonin that was absorbed, estimated from the area under the curve describing serum melatonin concentrations as a function of time after melatonin administration (the concentration-time curve), varied by 25-fold among subjects. 3 additional volunteers received three melatonin-containing capsules (80 mg each) at 60-min intervals. This regimen extended the duration of elevated serum melatonin levels to 4-6 h. Melatonin excretion closely paralleled serum melatonin levels until 9 h after the hormone's administration, after which urinary levels tended to be higher than those predicted from serum levels. However, the area under the concentration-time curve for serum melatonin correlated well (r = 0.96) with the cumulative melatonin excretion during the initial 15 h after melatonin's administration, indicating that either approach can be used to estimate the absorption of orally administered melatonin.

An extension of Chou's graphic rules for deriving enzyme kinetic equations to systems involving parallel reaction pathways

An extension has been made to the Chou's graphic rules in order to cover those enzyme-catalysed reaction systems in which there are two or more parallel reaction routes between any two enzyme species.

Light intensities required to suppress nocturnal melatonin secretion in albino and pigmented rats

Sprague-Dawley albino rats or Long-Evans pigmented rats were exposed during the dark phase of the daily light:dark cycle to various intensities of a sunlight-stimulating white fluorescent light (0.022, 0.044, 0.110, 0.220, 0.440 or 2.200 microW/cm2) for 30 min; pineal glands and trunk blood samples were then collected and assayed for melatonin by radioimmunoassay. Albino rats exposed to irradiances of 0.110 microW/cm2 or less had pineal melatonin levels that were not significantly different from those of unexposed animals; higher irradiances significantly (P less than 0.001) reduced melatonin levels. In contrast, as little as 0.022 microW/cm2 significantly (P less than 0.02) reduced pineal and serum melatonin levels in the pigmented rats. These results suggest that something other than the simple presence or absence of eye pigmentation is the critical factor in determining the sensitivity of the rat's pineal to retinal-mediated photic suppression of melatonin synthesis.

Prognosis of mercury poisoning in mercury refinery workers

The prognosis of chronic metallic mercury poisoning in two groups of patients from the mercury refinery of a mercury mine was evaluated by reexamination which included an interview, physical and neurological examination and determination of urinary mercury. Group I consisted of 70 male patients, who had been exposed to metallic mercury for 1.6-17.8 years, 15 of whom had been diagnosed 10 years earlier as having severe chronic metallic mercury poisoning, and the rest moderate chronic metallic mercury poisoning. At the time of reexamination, they had been removed from mercury exposure for 2 months-17 years. None of them had been treated with any chelating agent. Group 2 comprised 84 male patients from the same mercury mine, who had been exposed to metallic mercury for 2-10 years after 1962 and had been previously diagnosed as having mild chronic metallic mercury poisoning. They were reexamined after 2 months of hospital admission and chelation treatment with unithiol or sodium dimercaptosuccinate (Na-DMS). Based on clinical evaluation, the condition of the patients in both groups had all improved, even in the severe cases. The overall prognosis of chronic metallic mercury poisoning in mercury refinery workers was encouraging after termination of mercury exposure. Chelation therapy with unithiol or Na-DMS was evidently beneficial for reducing urine mercury and some symptoms, but not for neurological and stomal signs.