Environmental plastics in the context of UV radiation, climate change, and the Montreal Protocol.

There are close links between solar UV radiation, climate change, and plastic pollution. UV-driven weathering is a key process leading to the degradation of plastics in the environment but also the formation of potentially harmful plastic fragments such as micro- and nanoplastic particles. Estimates of the environmental persistence of plastic pollution, and the formation of fragments, will need to take in account plastic dispersal around the globe, as well as projected UV radiation levels and climate change factors.

Plastics in the environment in the context of UV radiation, climate change and the Montreal Protocol: UNEP Environmental Effects Assessment Panel, Update 2023.

This Assessment Update by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) considers the interactive effects of solar UV radiation, global warming, and other weathering factors on plastics. The Assessment illustrates the significance of solar UV radiation in decreasing the durability of plastic materials, degradation of plastic debris, formation of micro- and nanoplastic particles and accompanying leaching of potential toxic compounds. Micro- and nanoplastics have been found in all ecosystems, the atmosphere, and in humans. While the potential biological risks are not yet well-established, the widespread and increasing occurrence of plastic pollution is reason for continuing research and monitoring. Plastic debris persists after its intended life in soils, water bodies and the atmosphere as well as in living organisms. To counteract accumulation of plastics in the environment, the lifetime of novel plastics or plastic alternatives should better match the functional life of products, with eventual breakdown releasing harmless substances to the environment.

Effects of light qualities on growth and physiological-biochemical traits of Scutellaria baicalensis.

Canopy spectral composition significantly affects growth and functional traits of understory plants. In this study, we explored the optimal light condition suitable for enhancing Scutellaria baicalensis's yield and quality, aiming to provide scientific reference for the exploitation and utilization of medicinal plant resources in the understory of forests. We measured the responses of growth, morphology, biomass allocation, physiological traits, and secon-dary metabolites of S. baicalensis to different light qualities. S. baicalensis was cultured under five LED-light treatments including full spectrum light (control), ultraviolet-A (UV-A) radiation, blue, green, and red light. Results showed that UV-A significantly reduced plant height, base diameter, leaf thickness, leaf area ratio, and biomass of each organ. Red light significantly reduced base diameter, biomass, effective quantum yield of photosystem Ⅱ (ФPSⅡ), and total flavonoid concentration. Under blue light, root length and total biomass of S. baicalensis significantly increased by 48.0% and 10.8%, respectively, while leaf number and chlorophyll content significantly decreased by 20.0% and 31.6%, respectively. The other physiological and biochemical traits were consistent with their responses in control. Our results suggested that blue light promoted photosynthesis, biomass accumulation, and secondary metabolite synthesis of S. baicalensis, while red light and UV-A radiation negatively affected physiological and biochemical metabolic processes. Therefore, the ratio of blue light could be appropriately increased to improve the yield and quality of S. baicalensis.

Canopy structure and phenology modulate the impacts of solar radiation on C and N dynamics during litter decomposition in a temperate forest.

Decomposition of plant organic matter plays a key role in the terrestrial biogeochemical cycles. Sunlight has recently been identified as an important contributor to carbon [C] turnover through photodegradation, accelerating decomposition even in forest ecosystems where understorey solar irradiance remains relatively low. However, it is uncertain how C and nutrients dynamics respond to fluctuations in solar spectral irradiance caused by canopy structure (understorey vs. gaps) and season (open vs. closed canopy phenology). Spectral-attenuation treatments were used to compare litter decomposition over eight months, covering canopy phenology, in a temperate deciduous forest and an adjacent gap. Exposure to the full spectrum of sunlight increased the loss of litter C and lignin by 75% and 64% in the forest gap, and blue light was responsible for respectively 27% and 42% of that loss. Whereas in the understorey, C and lignin loss were similar among spectral-attenuation treatments over the experimental period, except prior to and during spring canopy flush when exposure to the full spectrum of sunlight promoted C loss by 15% overall, 80% of which was attributable to ultraviolet-B (UV-B) radiation. Nitrogen [N] was immobilized in the understorey during canopy flush before the canopy completely closed but N was swiftly released during canopy leaf-fall. Our study suggests that blue-driven photodegradation plays an important role in lignin decomposition and N dynamics in canopy gaps, whereas seasonal canopy phenology affecting sunlight reaching the forest floor drastically changes patterns of C and N in litter during decomposition. Hence, including sunlight dynamics driven by canopy structure and phenology would improve estimates of biogeochemical cycling in forests responding to changes in climate and land-use.

The contribution of photodegradation to litter decomposition in a temperate forest gap and understorey.

Litter decomposition determines carbon (C) backflow to the atmosphere and ecosystem nutrient cycling. Although sunlight provides the indispensable energy for terrestrial biogeochemical processes, the role of photodegradation in decomposition has been relatively neglected in productive mesic ecosystems. To quantify the effects of this variation, we conducted a factorial experiment in the understorey of a temperate deciduous forest and an adjacent gap, using spectral-attenuation-filter treatments. Exposure to the full spectrum of sunlight increased decay rates by nearly 120% and the effect of blue light contributed 75% of this increase. Scaled-up to the whole forest ecosystem, this translates to 13% loss of leaf-litter C through photodegradation over the year of our study for a scenario of 20% gap. Irrespective of the spectral composition, herbaceous and shrub litter lost mass faster than tree litter, with photodegradation contributing the most to surface litter decomposition in forest canopy gaps. Across species, the initial litter lignin and polyphenolic contents predicted photodegradation by blue light and ultraviolet B (UV-B) radiation, respectively. We concluded that photodegradation, modulated by litter quality, is an important driver of decomposition, not just in arid areas, but also in mesic ecosystems such as temperate deciduous forests following gap opening.

Hint1 Overexpression Inhibits the Cell Cycle and Induces Cell Apoptosis in Human Osteosarcoma Cells.

BACKGROUND: New evidence suggests that histidine triad nucleotide-binding protein 1 (Hint1) exerts a tumor suppressor effect in various human tumors, such as colorectal cancer and gastric cancer. However, it has not been reported whether Hint1 is involved in the occurrence and development of osteosarcoma (OS). MATERIALS AND METHODS: The present study investigated the role of Hint1 in human OS cells by using cell lines, including 143B, U2OS, KHOS-240S, Saos-2 and MG-63. Cell proliferation and apoptosis were detected by flow cytometry. RESULTS: The present result revealed that Hint1 is downregulated in these cell lines. The overexpression of Hint1 by adenovirus transfection in 143B and MG63 cell lines suppressed the proliferation and cell cycle, and increased the cell apoptosis. Mechanically, it was found that Hint1 downregulated the cyclin D1 expression via FOXO1 inhibition. Furthermore, FOXO1 overexpression in the 143B and MG63 cell lines significantly blurred the effects of Hint1 on cellular proliferation and apoptosis. CONCLUSION: The present study indicates that Hint1 inhibits the development of OS by regulating FoxO1-cyclin D1, suggesting that Hint1 may be a new method for the treatment of OS.

The renal protect function of erythropoietin after release of bilateral ureteral obstruction in a rat model.

Congenital urinary tract obstruction is one of the most frequent malformations in fetuses or neonates, which usually causes profound impairment of renal function including reductions in both glomerular filtration rate (GFR) and tubular handling of water and solutes. Although obstruction can be released by surgical operation, the child will suffer from diuresis for sometime. It has been reported that erythropoietin (EPO) could prevent the down-regulation of aquaporin-2 (AQP2) and urinary-concentrating defects induced by renal ischemia/reperfusion (I/R) injury. However, whether EPO could promote the recovery of renal function and AQP2 expression after releasing of ureteral obstruction has not been reported yet. The purposes of the present study were to investigate the effects of EPO on renal function and AQP2 expression after release of bilateral ureteral obstruction (BUO-R) in rats. The results showed that EPO could promote interleukin (IL) 10 (IL-10) expression; inhibit tumor necrosis factor-α (TNF-α), IL-6, and inducible nitric oxide synthase (iNOS) expressions; reduce the fractional excretion of sodium (FENa) and plasma creatinine (CREA) and urea; and promote the recovery of water and salt handling and AQP2 expression in BUO-R rats, especially in the high dose of EPO-treated group rats. In conclusion, EPO could promote the recovery of renal function and AQP2 expression in BUO-R rats, which may partially associate with its anti-inflammation effect.

Valsalva leak point pressure-associated Q-tip angle and simple female stress urinary incontinence symptoms.

PURPOSE: To clarify the association between clinically defined simple stress urinary incontinence (SUI) symptoms and urodynamic SUI, we examined the relationship between Valsalva leak point pressure (VLPP) as measured by the Q-tip test and Stamey grade in simple female SUI. METHODS: Two hundred grade I or II female SUI patients with SUI symptom were examined by reviewing medical history; physical examination; urethral mobility as assessed by Q-tip test; stress test; and cystometry, including VLPP measurement. On the basis of the VLPP, patients were classified into urethral hypermobility [UH, subdivided into anatomical incontinence (AI) and equivocal incontinence (EI)] or intrinsic sphincter deficiency groups for analysis of the relationship between VLPP and Stamey grade and Q-tip angle. RESULTS: Seventy-eight patients were included, and the mean patient age was 54 ± 7.5 years, mean SUI symptom duration 2.8 years (range 0.5-6 years), mean VLPP 103.6 ± 18.4 cm H2O, and mean Q-tip angle 28.6° ± 7.2°. Fifty-three patients were categorized as Stamey grade I, 25 as Stamey grade II, 51 as AI, and 27 as EI. VLPP was found to be negatively correlated with Q-tip angle (Rs = -0.798, Y = -0.313X + 60.95, P < 0.001), and classifications of VLPP and Stamey grade have positive correlation (χ (2) = 4.9130, P = 0.0267). CONCLUSIONS: In simple female SUI, VLPP is associated with the Q-tip angle and Stamey grade, which may help to reduce some of urodynamic items.

Association between salivary α-amylase activity and pain relief scale scores in cancer patients with bone metastases treated with radiotherapy.

BACKGROUND: Subjective assessment tools such as visual analog scales (VAS) or pain scores are commonly used to evaluate the intensity of chronic cancer-induced pain. However, their value is limited in some cases. We measured changes in VAS pain scores and salivary α-amylase (sAA) concentrations in cancer patients receiving radiotherapy for bone metastases to ascertain the correlation between these measures. METHODS: We enrolled 30 patients with bone metastases attending a single institution from June 2010 to March 2011. All patients with cancer-induced bone pain received radiation therapy (RT) at the same dose (30 Gy) and fractionation (3 Gy/fraction, 5 days/week) for palliative pain relief. We assessed heart rate (HR), systolic and diastolic blood pressures (DBP/SBP) and VAS pain scores before (d0) and after five (d5) and ten fractions (d10) of irradiation. sAA and salivary cortisol (SC) concentrations were measured using a portable analyzer and automated chemiluminescence analyzer, respectively. RESULTS: Radiotherapy markedly decreased VAS scores from (82.93 ± 9.29) to (31.43 ± 16.73) mm (P < 0.001) and sAA concentrations from (109.40 ± 26.38) to (36.03 ± 19.40) U/ml (P <0.001). Moreover, there was a significant correlation between these two indices (P <0.01, r = 0.541). HR decreased by 6.5% after radiotherapy, but did not correlate with VAS scores (P >0.05). SC concentrations and BP did not change significantly during the study (P >0.05). CONCLUSIONS: The significant correlation between sAA concentrations and VAS pain scores identified in these preliminary results suggests that this biomarker may be a valuable, noninvasive and sensitive index for the objective assessment of pain intensity in patients with cancer-induced bone pain.

Erythrocyte-based analgesic peptides.

Human erythrocyte discards the major organelles in a bid to maximize cellular hemoglobin. Hemoglobin, approximately 98% of the intraerythrocytic protein, serves as the principle transport medium of gaseous conveyance. The accumulated data speaks in favor of erythrocyte not merely engaging in gas exchange, but building molecular signaling as a side job during its 4-month sojourn in blood circulation. The production mechanism of erythrocyte-based bioactive peptides is not clear. Recent studies indicate that proteasome and its subunits persist in mature erythrocyte. The intraerythrocytic proteasome is involved in the formation of hemoglobin-derived analgesic peptides and enables erythrocyte to exert the erythrocrine function. Erythrocrine describes erythrocyte for generation and excretion of signaling molecules and has the potential of shedding light on our understanding of novel actions of erythrocyte. Different types of erythrocrine analgesic peptides are originated from the intraerythrocytic degradation of hemoglobin and manifest the systemic influence in physiology and pathophysiology along its travel through the body via the bloodstream. Translational research from bench to bedside will expand our knowledge of erythrocrine concept and facilitate the development of therapeutic strategies for clinical pain.

Poly[aqua[µ2-1,4-bis(imidazol-1-ylmethyl)benzene-κ2N3:N3'](µ2-5-hydroxybenzene-1,3-dicarboxylato-κ4O1,O1':O3,O3')cadmium(II)], a twofold interpenetrated CdSO4-like metal-organic polymer.

In the title cadmium(II) complex, [Cd(C(8)H(4)O(5))(C(14)H(14)N(4))(H(2)O)](n), the 5-hydroxybenzene-1,3-dicarboxylate (5-OH-1,3-bdc) and 1,4-bis(imidazol-1-ylmethyl)benzene (1,4,-bix) ligands bridge water-coordinated Cd(II) atoms to generate a three-dimensional network. Two carboxylate groups from different ligands function as O,O'-chelates, while two imidazole N atoms from different ligands coordinate in a monodentate fashion, and one water molecule completes the seven-coordinate pentagonal bipyramid around the Cd(II) atom, in which the N atoms occupy the axial sites and the O atoms occupy the equatorial sites. The overall architecture is a twofold interpenetrated CdSO(4)-type framework. The two crystallographically equivalent frameworks are linked by O-H···O hydrogen bonds between the water, hydroxy and carboxylate groups.

Urodynamic parameters development and complications of clean intermittent self-catheterization in Chinese schoolchildren with neurogenic underactive bladder.

OBJECTIVE: To evaluate the urodynamic parameters, development of bladder function and complications of clean intermittent self-catheterization (CIC) in Chinese schoolchildren with neurogenic underactive bladder. METHODS: Ninety-three children with neurogenic underactive bladder were successfully treated with CIC or combined with oxybutynin for two years follow-up. According to bladder compliance before CIC, they were subdivided into a normal bladder compliance (NBC) group and a low bladder compliance (LBC) group. Urodynamic parameters and complications were recorded. RESULTS: At follow-up, the incidence of neurogenic detrusor overactivity was found to have significantly decreased in both groups. Moreover, maximum cystometric capacity (CC) and relatively safe CC in the NBC group was significantly higher than those before CIC. However, relatively safe CC was significantly lower than that before CIC, and detrusor leakage point pressure was significantly higher than that before CIC in the LBC group. The incidences of bacteriuria, vesicureteral reflux (VUR), febrile urinary tract infections (UTI) and macroscopic hematuria were, respectively, 62, 13, 25 and 15%, and those of VUR and febrile UTI in the LBC group were significantly higher than those in the NBC group. CONCLUSION: For these cases, the complications of CIC are rare, and bladder compliance seems to be correlated with the development of bladder function and complications during CIC.

catena-Poly[[aqua(11-chloropyrido[2',3':2,3]pyrimidino[5,6-f][1,10]phenanthroline-kappa2N4,N5)cadmium(II)]-mu-benzene-1,4-dicarboxylato-kappa3O1,O1':O4]: an inclined interpenetrating (6,3) network.

The asymmetric unit of the title compound, [Cd(C(8)H(4)O(4))(C(17)H(8)ClN(5))(H(2)O)](n), contains one Cd(II) atom, two half benzene-1,4-dicarboxylate (1,4-bdc) anions, one 11-chloropyrido[2',3':2,3]pyrimidino[5,6-f][1,10]phenanthroline (L) ligand and one coordination water molecule. The 1,4-bdc ligands are on inversion centers at the centroids of the arene rings. The Cd(II) atom is six-coordinated by two N atoms from one L ligand, three carboxylate O atoms from two different 1,4-bdc ligands and one water O atom in a distorted octahedral coordination sphere. Each Cd(II) center is bridged by the 1,4-bdc dianions to give a one-dimensional chain. Pi-pi stacking interactions between L ligands of neighboring chains extend adjacent chains into a two-dimensional supramolecular (6,3) network. Neighboring (6,3) networks are interpenetrated in an unusual inclined mode, resulting in a three-dimensional framework. Additionally, the water-carboxylate O-H...O hydrogen bonds observed in the network consolidate the interpenetrating nets.

Poly[diaqua[mu-1,4-bis(imidazol-1-ylmethyl)benzene-kappa2N3:N3'](mu-trans-cyclohexane-1,4-carboxylato-kappa2O1:O4)manganese(II)]: a three-dimensional hydrogen-bonding alpha-polonium net.

In the title coordination compound, [Mn(C8H10O4)(C14H14N4)(H2O)2]n, each Mn(II) centre occupies an inversion centre. The 1,4-bis(imidazol-1-ylmethyl)benzene (1,4-bix) ligand and the trans-cyclohexane-1,4-dicarboxylate dianion (chdc) both function in bridging modes, linking adjacent Mn(II) centres into a two-dimensional four-connected (4,4) network. These two-dimensional layers are stacked in a parallel mode. Hydrogen bonds between water molecules and carboxylate O atoms link neighbouring (4,4) networks, yielding a three-dimensional alpha-polonium net.

Effect of a conserved peptide derived from Kunitz domain of hepatitis B virus x protein on the cell cycle and apoptosis of HepG2 cells via the proteasome pathway.

BACKGROUND: Hepatitis B virus (HBV) x protein (HBx) in HepG2 cells causes a moderate decrease in proteolysis activity of the proteasome. A highly conserved Kunitz-type serine protease inhibitor domain within 154 amino acid residues of HBx has been identified. In this study, a peptide chain derived from the Kunitz domain (PKD) was used to study its effect on the cell cycle and apoptosis of HepG2 cells, and investigated the function of PKD on the activities of proteasomes and AAA-ATPase p97, which involves in the ubiquitin-proteasome protein degradation pathway. METHODS: The PKD peptide (Phe-Val-Leu-Gly-Gly-Cys-Arg-His-Lys) was chemically synthesized. MTT assays were used to determine the effects of PKD on HepG2 cell growth. Mouse anti-p97 antibody was developed for Western blotting to detect the expression of p97. ATPase activity of proteasomes was measured using a colorimetric assay. Peptidase activities of proteasomes were analyzed with various peptidase-specific fluorogenic peptide substrates. Flow cytometry was used to determinate cell cycle phase and apoptosis. RESULTS: Viability of HepG2 cells decreased in a PKD-dose-dependent manner. Cells exhibited significant cytotoxicity in the presence of 15 mmol/L of PKD. Western blotting analysis showed that expression of p97 was suppressed in HepG2 cells treated with PKD compared to untreated cells. The ATPase activity of proteasomes from immunoprecipitates of HepG2 cells pretreated with PKD was apparently decreased. Chymotryptic activity of proteasomes in HepG2 cells was significantly inhibited by 10 mmol/L PKD; tryptic activity and peptidylglutamyl peptide hydrolase activity of proteasomes were less inhibited by PKD than chymotryptic activity. The cell cycle phase of HepG2 cells treated with PKD for 36 hours was blocked largely at the G(0)-G(1) phase, while untreated control cells were mainly in S phase. PKD also significantly induced apoptosis. CONCLUSIONS: The peptide derived from Kunitz domain of HBx protein induces HepG2 cell growth arrest and apoptosis, which may result from down-regulation of p97 expression, and decrease of both the ATPase and chymotryptic activities of proteasomes.

The effect of familial aggregation on the children with primary nocturnal enuresis.

OBJECTIVE: To evaluate the effect of familial aggregation on the children with PNE by evaluating nocturnal urine output, bladder, and arouse function. PATIENTS AND METHODS: According to whether relatives of family of probands over three generations were affected by PNE, forty-five children with familial aggregation PNE (FPNE), seventy children with sporadic PNE (SPNE) and ten children with normal lower urinary tract function but waiting for operation (control group) were included. Questionnaire of arousal from sleep (AS scores), bladder diary and daytime urodynamic studies were performed in all patients. RESULTS: The incidences of severe PNE and nonmonosymptomatic PNE in FPNE group were significantly higher than those in SPNE group. The nocturnal urine output and AS scores in both PNE groups was significantly higher, maximal voided volume significantly smaller than those in control group. Moreover, the incidences of small bladder in FPNE group was 44%, significantly higher than that in SPNE group (21%), but no significantly difference was found in nocturnal polyuria and arousal AS scores between two PNE groups. There were 53% patents with daytime detrusor overactivity and 60% patents with urodynamic functional bladder outflow obstruction in FPNE group, significantly higher than those in SPNE group (19% and 37%). Maximum cystometric capacity significantly decreased from control group to FPNE group. CONCLUSION: Familial aggregation has significant effects on the children with PNE, and FPNE are more likely to be severe symptoms and bladder dysfunction. It would be beneficial to have an urodynamic study for their diagnosis and treatment. Neurourol. Urodynam. 28:423-426, 2009. (c) 2008 Wiley-Liss, Inc.

[Proteasome inhibitor bortezomib sensitizes Hep-2 human laryngeal squamous cell carcinoma cells to ionizing radiation in vitro and in vivo].

OBJECTIVE: To determine if proteasome inhibitor bortezomib leads to enhanced radiation sensitivity of Hep-2 human laryngeal cancer cells and the relative mechanisms. METHODS: Hep-2 cells with or without bortezomib were irradiated at 0, 2, 4, 6, 8, and 10 Gy. Growth and clonogenic survival data were obtained to assess effects of treatment on radiosensitization. In vitro results were tested in vivo using a Hep-2 xenograft model. Nuclear factor-kappaB (NF-kappaB) activation was determined by Trans AM NF-kappaB P65 kit. The distribution of cell cycle and apoptosis were evaluated by flow cytometry. Morphological evidence of apoptotic cells were observed with Hochest 33342. RESULTS: It decreased cell growth and clonogenic survival. A 34% increase in radiosensitivity was observed for cells treated with bortezomib and radiation. Enhancement factor (EF) was 1.46 in Hep-2 xenografts receiving radiation and bortezomib. NF-kappaB activation was induced by radiation and inhibited by pretreatment with bortezomib, and was in a dose-dependent manner (r = 0.989, P < 0.05). Hep-2 cells treated with 100 nmol/L Bortezomib were arrested at G2-M phase (t = 22.31, P = 0.000) and resulted in all increased apoptosis with and without irradiation (P < 0.01). Morphological evidence of apoptotic cells could be distinguished under the fluorescence microscope after staining with Hochest 33342. Many nuclear fragments were observed in Hep-2 cells with bortezomib. CONCLUSION: Bortezomib could enhanced the radiosensitivity of Hep-2 laryngeal cancer cells by regulation of the distribution of cell cycle.

Is it possible to use urodynamic variables to predict upper urinary tract dilatation in children with neurogenic bladder-sphincter dysfunction?

OBJECTIVE: To investigate the possibility of using urodynamic variables to predict upper urinary tract dilatation (UUTD) in children with neurogenic bladder-sphincter dysfunction (NBSD). PATIENTS AND METHODS: The study included 200 children with NBSD, of whom 103 had UUTD and 97 did not; they were examined using routine urological, neurological and urodynamic methods. The group with UUTD was divided into three subgroups (group 1-3, from mild to severe hydronephrosis). A urodynamic risk score (URS) was calculated, including a detrusor leak-point pressure (DLPP) of >40 cmH2O, a bladder compliance (BC) of <9 mL/cmH2O and evidence of acontractile detrusor (ACD). RESULTS: The postvoid residual urine volume (PVR), DLPP, incidences of ACD and DLPP of >40 cmH2O were greater and the BC significantly less in groups 1-3 than in the control group. Moreover, the BC decreased, while the PVR, DLPP and the incidence of DLPP of >40 cmH2O were significantly higher in group 3 than in group 2. The relative safe cystometric capacity of groups 2 and 3 were lower, respectively, than that of the control and group 1, and the relative unsafe cystometric capacity (RUCC) and relative risk rate of cystometric capacity (RRRCC) were significantly greater with the severity of UUTD. The maximum detrusor pressure on voiding or at maximum flow rate, and the Abrams-Griffiths number for voluntary contractile bladders, of the UUTD group were significantly higher than those of the control group. There was a positive correlation between URS and UUTD. CONCLUSIONS: The selective use of urodynamic variables might be valuable for predicting the risk of UUTD in children with NBSD. Decreased BC, and increased DLPP and ACD are the main urodynamic risk factors, and they reciprocally increase the occurrence and grades of UUTD. The grades of UUTD are compatible with increases in RUCC, RRRCC and URS.

[Characteristics of urinary continence mechanisms of the lower urinary tract in late pregnancy].

OBJECTIVE: To investigate the characteristics of the urinary continence mechanisms of the lower urinary tract in late pregnant women. METHODS: A total of 47 volunteer women without urinary leakage in late pregnancy were selected as the study group. Twenty-seven non-pregnant women with normal lower urinary tract function were included in control group. Urodynamic studies were performed on all women. RESULTS: The maximum flow rate [(20 +/- 13), (32 +/- 7) ml/s; P < 0.05], the voided volume and the normal desire cyst volume [(163 +/- 13), (226 +/- 85) ml vs (436 +/- 19), (338 +/- 56) ml; P < 0.05] of the late pregnant group and control group were different significantly; residual urine which was less than 10 ml was found in seven pregnant women. Compared with the control group, the maximum urethral pressure, the maximum urethral closure pressure and the functional urethral length of the study group were increased obviously (P < 0.05). CONCLUSION: The sufficient increase of the static urethral pressure profile in late pregnancy could compensate for the progressive increase in bladder pressure during pregnancy, which is beneficial to maintain the urinary continence mechanisms in pregnancy.