The long-term results of pubovaginal sling surgery using acellular cross-linked porcine dermis in the treatment of urodynamic stress incontinence

PURPOSE: Acellular cross-linked porcine dermis is a potential substitute for rectus fascia as a sling material with the advantage of decreased morbidity. However, the long-term efficacy is unknown. We compared the 3-year efficacy of PD vs autologous rectus fascia as a sling material for pubovaginal sling surgery in the treatment of urodynamic stress incontinence. MATERIALS AND METHODS: Between July 2000 and December 2001 a total of 101 consecutive, nonrandomized patients with USI underwent a PD (51) or RF (50) sling procedure. Patients were assessed at 6 weeks, and at 3, 6 and 12 months postoperatively. Urodynamic study was repeated in cases of treatment failure. A detailed survey questionnaire was mailed to all patients at least 36 months after surgery and all responders were then retested by telephone interview by a blinded assessor. The primary outcome measure was patient perceived success rate (cured or improved) at least 36 months after PVS. Secondary outcome measures were patient satisfaction 36 months after surgery, durability of success with time and reoperation rate. RESULTS: Complete data were available on 94 patients (48 treated with PD and 46 treated with RF sling). The groups were well matched for age, leak point pressure, prior incontinence surgery and urge symptoms. Pubovaginal sling was successful (cured or improved) in 37 (80.4%) patients treated with RF but in only 26 (54%) patients treated with PD 36 months after surgery (Fisher's exact test p = 0.009; 95% CI 8.03, 44.4). Treatment failure occurred by 9 months after RF and by 24 months after PD sling procedure. Repeat urodynamic study showed USI to be the cause of treatment failure in 18 (37.5%) of 20 patients treated with PD but in only 3 (6.5%) of 8 patients treated with RF. CONCLUSIONS: We have shown that use of the PD sling, although reducing early morbidity, results in a significantly inferior long-term cure rate in comparison to the RF sling. Therefore, acellular cross-linked porcine dermis should not be used as a substitute for rectus fascia.     

Screening of crude extracts of six medicinal plants used in South-West Nigerian unorthodox medicine for anti-methicillin resistant <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> activity

Background  

Six Nigerian medicinal plants Terminalia avicennioides, Phylantus discoideus, Bridella ferruginea, Ageratum conyzoides, Ocimum gratissimum and Acalypha wilkesiana used by traditional medical practitioners for the treatment of several ailments of microbial and non-microbial origins were investigated for in vitro anti-methicillin Resistant Staphylococcus aureus (MRSA) activity.     

In-vitro evaluation of anti-trichomonal activities of Eugenia uniflora leaf

Eugenia uniflora, used ethnomedically in some tropical countries as an anti-infective, has shown anti-malarial and anti-trypanocidal activities. Therefore using bioactivity guided fractionation, anti-trichomonal activity of E. uniflora leaf was investigated. Anti-trichomonal activities of leaf methanol extract and its fractions against Trichomonas gallinae as well as their cytotoxicities using an in vitro haemaglutination assay were determined. Anti-trichomonacidal activities of the extract improved on purification up to a stage. Subfractions E(2-5) had LC(50) and LC(90) values of 4.77 - 5.28, 18.49 - 25.00 and 4.53 - 5.18, 18.32 - 19.07 μg/ml at 24 and 48 hrs, respectively that were better than those of metronidazole. Further purification of E(2-5) led to loss of activity suggesting that the active components were probably working synergistically and additively. Demonstration of low haemaglutination titre values of 0.00 - 5.33 by methanolic extract and its partition fractions suggested their low toxicity profile. The established safety of the leaf indicated that its anti-trichomonal activity was not due to non-specific cytotoxicity, hence could be used in ethnomedicine as an anti-trichomonal agent.     

Eco-toxicological and epidemiological assessment of human exposure to polycyclic aromatic hydrocarbons in the Niger Delta, Nigeria

Epidemiological examinations of polycyclic aromatic hydrocarbons (PAHs) exposure in biological bodies have shown the potential risk of cancer induction. Environmental media containing PAHs were analyzed in the Niger Delta region. Gas chromatographicmass spectrometric analyses were carried out on samples and 98% of the samples contained carcinogenic PAHs. The concentration of the 7 potential carcinogenic PAHs (?? _carc ^soil 7PAHs) in the soils varied from 297?C4080.6±546.3 mg/kg (min-max +/- standard deviation) with a median of 419 mg/kg, the concentrations for non-carcinogenic PAHs ranged from 315?C1999±300 mg/kg with a median of 497.5 mg/kg. The total concentrations of PAHs (?total H2O17PAHs) in water samples varied from 119.8?C450.0±117.9 mg/L with a median of 141.9 mg/L, while the sediment concentrations ranged from 6.0?C132.0±28.7 mg/L with a median of 62.73 mg/L. Concentrations of benzo(a) pyrene (BaP), which most likely originated from crude oil spillage in the area was determined as 66.95±73.47 mg/kg in soil samples. To evaluate human exposure to carcinogenic PAHs sources, the toxic equivalence factors (TEFs), mutagenic potency equivalent factors (MEFs) and the incremental lifetime cancer risk (ILCR) methodologies were used to calculate the exposure risk. Carcinogenic equivalents (BaP-TEQ) and mutagenic equivalents (BaP-MEQ) were calculated from the potency relative to BaP (TEF) and BAP (MEF) respectively. BaP-TEQ (mg/kg) for ?? _carc ^soil 7PAHs were determined as 98.80±125.81 and varied from 68.20?C953.84 mg/kg, while the BaPMEQ (mg/kg) for ?? _carc ^soil 7PAHs were determined as 124.01±163.37 and varied from 87.24?C1237.82 mg/ kg. The BaP-TEQ (mg/kg) for ?? _carc ^H2O 7PAHs were determined as 16.79±14.44 and varied from 5.55?C52.69 mg/L, similarly the BaP-MEQ (mg/kg) for ?? _carc ^H2O 7PAHs were determined as 9.29±8.15 and varied from 1.55?C29.80 mg/kg. The cumulative ILCR from the water and soil contaminations were determined as 1.13×10^?4 and 6.42×10^?4 respectively for children, while values of 1.09×10^?4 and 6.19×10^?4 were determined respectively for adult. The ecotoxicological assessments in this study indicate contamination of environmental media in the region with high potential of acute toxicity sufficient enough to induce carcinogenic effects and chronically affect the human health of residents with prolonged exposures.     

Synthesis and cytotoxic activities of some 2-Arylnaphtho[2,3-d]oxazole-4,9-dione derivatives on androgen-dependent (LNCaP) and androgen-independent (PC3) human prostate cancer cell lines

The synthesis of five 2-arylnaphtho[2,3-d]oxazole-4,9-dione derivatives was accomplished by refluxing 2-amino-3-bromo-1,4-naphthoquinone with appropriate benzoyl chloride analogs at elevated temperatures. In vitro anticancer evaluation of these compounds was performed on androgen-dependent, LNCaP, and androgen-independent, PC3, human prostate cancer cell lines. In general, these compounds displayed slightly stronger cytotoxicity on the androgen-dependent LNCaP than on the androgen-independent PC3 prostate cancer cell lines. The meta-substituted 2-(3-Chloro-phenyl)-naphtho[2,3-d]oxazole-4,9-dione (10) appear to display the best cytotoxicity on both cell lines with an IC(50) of 0.03 μM on LNCaP and 0.08 μM on PC3 after 5 days of exposure.     

Phosphatidylinositol-4-phosphate-5-kinase alpha deficiency alters dynamics of glucose-stimulated insulin release to improve glucohomeostasis and decrease obesity in mice

OBJECTIVE

Phosphatidylinositol-4-phosphate-5-kinase (PI4P5K) has been proposed to facilitate regulated exocytosis and specifically insulin secretion by generating phosphatidylinositol-4,5-bisphosphate (PIP₂). We sought to examine the role of the α isoform of PI4P5K in glucohomeostasis and insulin secretion.

RESEARCH DESIGN AND METHODS

The response of PI4P5Kα^−/− mice to glucose challenge and a type 2-like diabetes-inducing high-fat diet was examined in vivo. Glucose-stimulated responses and PI4P5Kα^−/− pancreatic islets and β-cells were characterized in culture.

RESULTS

We show that PI4P5Kα^−/− mice exhibit increased first-phase insulin release and improved glucose clearance, and resist high-fat diet-induced development of type 2-like diabetes and obesity. PI4P5Kα^−/− pancreatic islets cultured in vitro exhibited decreased numbers of insulin granules docked at the plasma membrane and released less insulin under quiescent conditions, but then secreted similar amounts of insulin on glucose stimulation. Stimulation-dependent PIP₂ depletion occurred on the plasma membrane of the PI4P5Kα^−/− pancreatic β-cells, accompanied by a near-total loss of cortical F-actin, which was already decreased in the PI4P5Kα^−/− β-cells under resting conditions.

CONCLUSIONS

Our findings suggest that PI4P5Kα plays a complex role in restricting insulin release from pancreatic β-cells through helping to maintain plasma membrane PIP₂ levels and integrity of the actin cytoskeleton under both basal and stimulatory conditions. The increased first-phase glucose-stimulated release of insulin observed on the normal diet may underlie the partial protection against the elevated serum glucose and obesity seen in type 2 diabetes-like model systems.Failure of pancreatic β-cells to release adequate amounts of insulin contributes to the onset of type 2 diabetes and obesity (1). Elevated serum glucose transported into pancreatic β-cells is metabolized to increase cytosolic ATP levels, which then promote closure of ATP-sensitive K⁺ (KATP) channels, causing membrane depolarization. Membrane depolarization triggers opening of L-type Ca²⁺ channels, influx of Ca²⁺, and exocytosis. The first phase of exocytosis entails fusion of primed insulin granules predocked at the plasma membrane (2). A second phase involving mobilization of distal insulin vesicles occurs after approximately 10 min (3), preceded by actin cytoskeletal reorganization (4–6) and generation of lipid second messengers (7,8). The majority of type 2 diabetes is only weakly associated with specific genetic defects and is characterized by inadequate release of insulin, in addition to insulin resistance exhibited by fat and muscle target cells. Prolonged stimulation of β-cells by elevated levels of glucose, such as is encountered in the typical western-style high-fat diet, eventually suffices to trigger changes in insulin secretion in many individuals with otherwise seemingly normal physiology and genetics.Lipid kinases and their phosphoinositide products play important roles in secretory vesicle trafficking (9). Type I phosphatidylinositol-4-phosphate-5-kinases (PI4P5Ks) α, β, and γ generate the signaling lipid phosphatidylinositol-4,5-bisphosphate (PIP₂). Elegant studies in neurons and neuroendocrine cells on the role of PI4P5Kγ (10,11) and PIP₂ (12–14) have revealed that PIP₂ generation at the plasma membrane is critical during regulated exocytosis. PIP₂ directly facilitates some types of Ca⁺⁺ signaling (15,16), recruits proteins that facilitate the fusion process (13,14), and is required for docked secretory vesicles to undergo priming to become part of the ready-releasable pool and then fuse into the plasma membrane (10,11). Although less well understood mechanistically, decreased levels of PIP₂ have also been shown to inhibit insulin secretion in pancreatic β-cell model systems (7,17–19).However, PIP₂ also carries out functions that potentially oppose regulated exocytosis (20). First, PIP₂ supports the open state of the KATP channel (21,22); thus, because it is ATP-driven closure of the KATP channel that triggers secretion, PIP₂ deficiency might be anticipated to decrease K⁺ efflux, triggering membrane depolarization and thus increasing Ca⁺⁺ currents, resulting in increased secretion (23–25). In support of this model, expression of a dominant-negative isoform of PI4P5K to lower levels of PIP₂ changes the responsiveness of mutant KATP channels with decreased ATP sensitivity. However, expression of the dominant-negative PI4P5K does not alter function of wild-type (WT) KATP channels, suggesting that under normal physiologic conditions, the level of PIP₂ on the plasma membrane is not high enough to strongly affect KATP channel activity (26). PIP₂ has also been suggested to restrain fusion of docked vesicles by inhibiting SNARE complex function (14,27), with the restraint being alleviated through sequestration of the PIP₂ by Syntaxin-1 (14) or Ca²⁺-triggered PIP₂ destruction (28).Taken together, the action of PIP₂ is complex, and both its synthesis and its turnover are required at different steps in the fusion process.Another function undertaken by PIP₂ is to promote assembly of actin filaments (F-actin) (29,30). F-actin at the periphery of the cell (cortical F-actin) has also been proposed to have both positive and negative regulatory functions in exocytosis. Cortical F-actin has been proposed to act as a barrier to block access of undocked secretory vesicles to the plasma membrane; consistent with this model, cortical F-actin is disassembled during regulatory exocytosis events (31), and pharmacologic agents that disassemble F-actin enhance movement of insulin granules to the plasma membrane and insulin release, whereas agents that stabilize the actin cytoskeleton decrease insulin release (4,18,32–34). F-actin may also affect SNARE complex function by binding to and inhibiting Syntaxin-4 function in a glucose stimulation-relieved manner (32,33). To further complicate matters, F-actin can also undertake a positive role in regulated exocytosis by mediating translocation of more internal secretory vesicles to the periphery, particularly in poorly granulated or recently degranulated cells (4,35). Thus, dynamic regulation of the actin cytoskeleton is also important in the progression of regulated exocytosis and can play positive or negative roles depending on the setting.Changes in PIP₂ and cortical F-actin can have positive and negative effects on the secretory process, making it difficult a priori to predict the outcomes of their physiologic and experimental manipulation. Critically, individual PI4P5K isoforms may generate subpools of PIP₂ that regulate distinct components of the fusion process. Deletion of PI4P5Kγ markedly decreases levels of PIP₂ at the plasma membrane in resting neurons and neuroendocrine cells, and inhibits secretion at the stage of vesicle priming and fusion without notable effect on the actin cytoskeleton (10,11). In contrast, deletion of PI4P5Kα increases mast cell degranulation triggered by cross-linking of the IgE receptor, accompanied by minor decreases in cellular PIP₂, but significantly increased levels of Ca²⁺ signaling and decreased levels of total F-actin (36). PI4P5Kα knockdown using RNAi has also been reported to alter Ca²⁺ signaling, disrupt F-actin, and affect insulin release in a pancreatic β-cell line (37).This report examines insulin secretion in PI4P5Kα^−/− mice and finds that first-phase insulin release is augmented, and on a high-fat diet, fasting and stimulated serum insulin levels are even more elevated, conferring faster glucose clearance and resistance to the development of obesity. In this setting, K⁺ and Ca⁺⁺ signaling is seemingly normal; in contrast, the determinative factor seems to be a dramatic stimulation-dependent loss of PIP₂ at the plasma membrane that leads to reorganization of the actin cytoskeleton resulting in a near-total loss of cortical F-actin and decreased numbers of insulin granules docked at the plasma membrane.     

Association between electrocardiographic left ventricular hypertrophy with strain pattern and left ventricular structure and function

BACKGROUND AND PURPOSE: Electrocardiographic left ventricular hypertrophy (LVH) with strain pattern has been documented as a marker for LVH. Its presence on the ECG of hypertensive patients is associated with poor prognosis. The study was carried out to assess the association of the electrocardiographic strain with left ventricular mass (LVM) and function in hypertensive Nigerians. MATERIAL AND METHODS: ECG as well as echocardiograms were performed in 64 hypertensive patients with ECG-LVH and strain pattern, 65 patients with ECG-LVH by Sokolow-Lyon (SL) voltage criteria and 62 normal controls. RESULTS: The study showed that electrocardiographic left ventricular (LV) strain pattern is associated with dilated left atrium, larger LV internal dimensions and greater absolute and indexed LVM in hypertensive Nigerians compared with ECG-LVH by SL voltage criteria alone or normal controls. CONCLUSION: The findings of this study support the fact that the ECG strain pattern is associated with increased LVM and an increased risk of developing abnormal LV geometry.