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Biomedical subjects

X Fu

Publications and source records attributed to X Fu.

At least 127 records · Page 7Linked to original sources
PubMed1996

Effects of progesterone and oxytocin on intracellular elemental composition of term human myometrium in vitro.

OBJECTIVE: To study the effects of progesterone and oxytocin on contractile activity related to the intracellular elemental composition of human pregnant myometrium. STUDY DESIGN: Myometrial strips were mounted in tissue baths and superfused with plain buffer, oxytocin or progesterone. Progesterone was initially added to the tissue bath or at the onset of spontaneous contraction of the strips. The myometrial contractile activities were recorded isometrically and the results were analyzed by a specific computer program. The effects of oxytocin and progesterone on the intracellular elemental composition were studied by X-ray microanalysis in an electron microscope. RESULTS: The contractile activity in terms of frequency and tonus of the muscle strips was increased by oxytocin and progesterone. This increase was more pronounced if progesterone was added to the bath at the start of the experiment. After 120 min of incubation with oxytocin and progesterone the total intracellular concentration of calcium was significantly higher (P < 0.0001 and P < 0.002, respectively) compared to buffer. CONCLUSIONS: (i) Oxytocin increases total intracellular calcium concentration concomitant with an increase in uterine contractile activity. (ii) Progesterone increases the myometrial tone and frequency of contractions, simultaneously with an increase in total intracellular calcium.

Calcium↗
PubMed1996

Progesterone, oestradiol and oxytocin and their in vitro effect on maintaining the number of gap junction plaques in human myometrium at term.

Previous studies by electron microscopy and laser confocal microscopy of immunohistochemically stained sections have shown that during pregnancy the extent of gap junction formation in human myometrium is low, but that an increase occurs in the active stages of labour despite a high concentration of progesterone in maternal blood. The present investigation focused on the effect of in vitro exposure of isolated myometrial tissue to progesterone, oestradiol and oxytocin, on the number of gap junction plaques in human myometrium at term. Myometrial biopsies were obtained at term from 13 pregnant women who had an elective caesarean section in the 37th or 40th week of pregnancy. The biopsies were immersed immediately in Hepes buffer and buffer containing 0.5, 5.0 micrograms mL-1 of progesterone, and 0.1 micrograms mL-1 of oestradiol. The muscle biopsies were trimmed under a stereo microscope into strips along the bundles of smooth muscle cells and mounted in tissue baths, superfused with Hepes buffer supplemented with glucose (0.01 mM); subsequently the strips were exposed to buffer containing different concentrations of progesterone, oestradiol and oxytocin. Incubation of the muscle strips for 180 min resulted in a significant decrease of the number of gap junctions (P < 0.01). Neither oestradiol or oxytocin, alone or in combination, had a significant effect on the maintenance of the number of gap junctions. The progesterone concentration of 5.0 micrograms mL-1, combined with oxytocin, and with or without oestradiol has a significantly positive effect on the number of gap junction plaques in strips of human myometrium at term (P < 0.05 vs. buffer alone). The high concentration of progesterone in the superfusion medium during in vitro experiments may be responsible for the maintenance of high numbers of gap junction complexes in term human myometrium. This finding is of interest in the light of findings of persisting high progesterone levels in maternal blood during labour.

Estradiol↗
PubMed1996

Multiple organ injuries and failures caused by shock and reperfusion after gunshot wounds.

Experiments were performed to observe the changes of multiple system organ failure (MSOF) and gut barrier function caused by shock and reperfusion after gunshot wounds. Eighteen dogs were divided randomly into two groups. In the experimental group, the dogs were subjected to 60 minutes of shock (40mm Hg), followed by reinfusion of shed blood after hindlimb gunshot wounds. In the control group, the dogs experienced pure gunshot wounds without shock and reperfusion. The results showed that dogs in the experimental group developed multiple system organ injuries or failures compared with the control group. The levels of malondialdehyde (MDA) values in plasma were significantly elevated in the experimental group when compared with preinjury and the control group. Gut flora disorder, bacillus intestinalis overgrowth, and bacterial translocation occurred in the experimental group. The pathological results support the gut barrier function injury. The results indicated that pure gunshot wounds do not easily injure gut barrier function and produce MSOF. Gunshot wounds with shock and reperfusion are capable of causing gut flora disorder, bacillus intestinalis overgrowth, and lead to bacterial translocation, furthermore causing MSOF. Although fluid resuscitation is a potential treatment modality, pathogenically, it can lead to MSOF.

Animals↗
PubMed1996

In vivo effects of tumor necrosis factor-alpha on incised wound and gunshot wound healing.

Recombinant tumor necrosis factor alpha (TNF-alpha) was applied to incised wounds (adult rats, n = 14) and gunshot wounds (dogs, n = 5). The accumulation of RNA and DNA in regenerative tissue, the wound disruption strength (WDS), and histology were examined. The results showed that a single dose of TNF-alpha in saline with highly purified bovine serum albumin increased the WDS and accumulation of RNA and DNA in regenerative tissue in incised wounds 3 days after surgery (p < 0.05). Also, TNF-alpha promoted the inflammatory reaction in the wounded area of gunshot wounds. Histology revealed increased capillary tube-like structures and collagen formation and fibroblast proliferation in both incised and gunshot wounds treated with TNF-alpha. The results indicated that locally applied TNF-alpha benefited the incised and gunshot wound healing. These mitogenic and inflammatory effects of TNF-alpha may be the synergistic effects with other growth factors such as platelet-derived growth factor (PDGF).

Animals↗
PubMed1996

The ability of bile to scavenge superoxide radicals and pigment gallstone formation in guinea pigs.

After partial ligation of the common bile duct (CBD) of guinea pigs, 14 of 16 animals developed pigment gallstones within one week (S group). Intraperitoneal injection of Vit. E and C, each 10 mg/kg daily from 3 days before CBD ligation to one week after the operation (S+V group), decreased the gallstone incidence to 5/14 (exact probability < 0.01). The gallstone incidence in the control group, that only received laparotomy without ligation of the CBD, was 0/15. Biochemical analysis of the gallbladder bile showed that stricture of the CBD was associated with a significant increase in levels of unconjugated bilirubin (UCB) and Ca2+ (p < 0.05 and < 0.01). Simultaneously the scavenging rate (SR) of superoxide radical in bile significantly decreased (p < 0.05). Comparing S+V group with S group, the effect of Vit. E and C on the concentrations of UCB and Ca2+ in bile was not significant (both p > 0.05), but Vit. E and C normalized the SR, and the difference between S group and S+V group was significant (p < 0.05). These results suggested that Vit. E and C, known as antioxidants, enhanced the ability to scavenge oxygen radical in S+V group; and that in addition to the increases of UCB and Ca2+ concentrations, the participation of oxygen radicals might be of importance for pigment gallstone formation induced by bile duct obstruction.

Animals↗
PubMed1996

Effects of estradiol and interaction with progesterone or oxytocin on term human myometrial contractile activity.

BACKGROUND: To investigate the effects of estradiol (E2) alone and in combination with progesterone or oxytocin on contractile activity of term human myometrium in vitro. METHODS: Myometrial specimens were obtained from 24 term pregnant women not in labor who underwent elective cesarean. Biopsies were kept in ice-cold and oxygenated Hepes buffer and buffer containing different hormonal solutions. The biopsies were dissected and mounted in tissue baths at 37 degrees C and isometric tension was recorded. RESULTS: (1) Estradiol at 0.1 and 1 microgram/mL increased the contractile frequency (p < 0.01 for each), decreased the tonus (p < 0.05 and p < 0.01) and suppressed the activity area of contractions (p < 0.05 and p < 0.01) as compared to control. (2) No significant differences in frequency and activity area of contractions between strips superfused with E2 plus progesterone and progesterone alone were recorded. Myometrial tonus was decreased by 0.1 microgram/mL or 1 microgram/mL E2 plus progesterone as compared to progesterone alone (p < 0.05 and p < 0.01). (3) There were no significant differences in frequency between strips superfused with E2 plus oxytocin and oxytocin alone. Myometrial tonus was decreased by 0.1 microgram/mL or 1 micrograms/mL E2 plus oxytocin as compared with oxytocin alone (p < 0.05 and p < 0.01). Estradiol at 0.1 microgram/mL or 1 micrograms/mL plus oxytocin reduced the activity area of contractions compared to oxytocin (p < 0.05 and p < 0.01). CONCLUSIONS: These data suggest that E2 had both stimulatory and inhibitory effects on term human myometrial contractility and that E2 altered the myometrial response to progesterone and oxytocin mainly by decreasing tonus.

Adult↗
PubMed1996

[Relationship between wound healing and TNF, MDA and SOD contents in granulation tissues of rats in the first week].

An experimental model was used to determine the changes in TNF, MDA and SOD in granulation tissues during natural wound healing after skin excision on rats. Our results indicated that the changes in TNF and SOD exhibited a curve of V. The levels of TNF and SOD were lower on day 7 than day 3. The levels of MDA rose gradually, especially on day 7. A positive correlation was shown between TNF and MDA (at days 3, 5, 7), also between TNF and SOD (at day 3, 7). When the concentration of TNF was lower than 90 Pg/mg protein, the process of wound healing was best, while wound healing was hindered when the levels of SOD were low. The results suggest that in the process of wound repair there are influential changes in the contents of TNF, MDA and SOD. Lower levels of TNF and higher levels of SOD are apparently beneficial to wound healing after trauma.

Animals↗
PubMed1996

Presence of free radicals in pigment gallstone in vivo.

OBJECTIVE: To clarify whether free radical, which may play a role in pigment gallstone formation, is present in pigment gallstones in vivo. MATERIALS AND METHODS: Free radical signal of gallstones from 18 patients was detected by electron paramagnetic resonance spectroscopy at 77K under anaerobic condition and in air (control). As soon as the anaerobic determination was finished, the fresh anaerobic sample was exposed to air and stored in a freezer at -20 degrees C. RESULTS: Free radical signal (g = 2.0038) was detected in fresh anaerobic samples containing more than 2% bilirubin compound, and the signal intensity correlated linearly with the content of calcium bilirubinate (r = +0.95, P < 0.0005). During the storage at -20 degrees C and exposure to air, the signal intensity of each anaerobic sample and its control increased gradually, eventually reaching the same stable level. Fe(III) signal intensity was enhanced synchronously and related linearly with free radical signal (r = +0.99, P < 0.0005). CONCLUSIONS: Free radical exists originally in pigment gallstones in vivo, and it may play an important role in pigment gallstone formation. The free radical signal carried by gallstones may be strengthened by the action of oxygen in air on bilirubin. The transition metal ions probably take part in the formation of bilirubin free radical.

Bilirubin↗
PubMed1996

Ocular symptoms of tumors at sella turcica region.

BACKGROUND: The sella tumors were found in 15% of intracranial tumors. The sella turcica region locates in the base of skull, so the carcinoma patients in early stage often showed no intracranial hypertension and other positive signs of neural system. However, the patients presented visual field defect and hypopsia, and often went to see the doctor of ophthalmology, which resulted from that the tumor often compressed optic nerve and chiasm. We analysed the symptomatic changes of the visual organs in order to provide a diagnostic basis for sellar tumor in ophthalmological department. CLINICAL MATERIALS: Of the 407 cases of sellar tumors, 296 were pituitary adenoma, 52 were craniopharyngioma, 43 were meningioma, and the rest 16 were other kinds of sellar tumors. We analysed their ocular changes of the sellar tumors and the characteristics of the tumors. RESULTS: The sellar tumor in its early stage is mainly symptomized as visual field changes. Visual field defect was found in 92.9% of pituitary adnoma, 75% of craniopharyngioma and 34.8% meningioma patients. The patients of intermediate and later sellar tumors gradually manifested the hypopsia and optic atrophy. Hypopsia was found in 86.5% of pituitary adenoma patients, 89.9% of craniopharyngioma and 48.8% of meningioma patients. The morbidity rate of optic atrophy is 59.5% in patients with pituitary adenoma, 65.5% of craniopharyngioma and 44.1% of meningioma. CONCLUSION: The misdiagnostic rate of sellar tumor in ophthalmological department still keeps comparatively high. The reason is that: (1) The doctors lack the neuroophthalmological knowledge. (2) The patients were not examined attentively enough. The ocular symptoms of sellar tumors are often the first occurred and most important changes. In the clinical practice, all the patients showing visual acuity and visual field disturbances should be examined carefully (especially in visual field) and excluded ocular diseases, should be transferred to the department of neurosurgery for further diagnosis and treatment.

Adenoma↗
PubMed1995

Structural requirements of peptide and MHC for DR(alpha, beta 1*0401)-restricted T cell antigen recognition.

We identified functionally important regions of the DR(alpha, beta 1*0401) peptide binding site and present a model of bound peptide. DR(alpha, beta 1*0401)-restricted T cell recognition and peptide binding of Mycobacterium leprae (ML) peptide 38-50 and overlapping peptides from the 18-kDa heat-shock protein were analyzed. ML38-50 is unusual in its restricted binding pattern, binding to only one of five DR4 subtypes and no other DR molecules tested. Amino acid substitutions were introduced into ML38-50 and the DR(alpha, beta 1*0401) peptide binding site at positions likely to influence peptide-MHC or peptide- or MHC-TCR interactions. Peptide binding, T cell proliferation, and computer modeling studies suggest that residues 39F, 42E, and 44D of ML38-50 interact with pockets 1, 4, and 6, respectively, of the peptide binding site. Only DR(alpha, beta 1*0401) substitutions at residues in pockets 4 or 7 prevented binding of ML38-50, while multiple substitutions at other positions negatively affected its T cell recognition. In contrast, T cell recognition of some high affinity ML peptides that overlapped ML38-50, and contained N-terminal extensions, was only abolished with pocket 4 substitutions. An inverse correlation of peptide affinity for DR(alpha, beta 1*0401) with negative effects of MHC substitutions on T cell recognition of the overlapping ML peptides was observed. Thus, some regions, such as pocket 4, dominantly influence T cell recognition of multiple DR(alpha, beta 1*0401)-binding peptides. However, each DR(alpha, beta 1*0401)-binding peptide appears to have unique properties that determine the outcome of its MHC-peptide interactions and the relative importance of other polymorphic pockets.

Amino Acid Sequence↗