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PubMed2004

Metformin extended release--DepoMed: metformin, metformin gastric retention, metformin GR.

Metformin extended release [Glumetza, metformin hydrochloride, metformin gastric retention, metformin GR] is a proprietary once-a-day formulation of metformin hydrochloride under development with DepoMed for the treatment of diabetes. In May 2002, DepoMed licensed manufacturing and marketing rights for its proprietary formulation of metformin extended release (500mg dose) to Biovail Corporation for the US (including Puerto Rico) and Canada. Under the terms of the agreement, Biovail would pay a $25 million milestone fee upon approval and also customary royalties on the net sales in the US and Canada. Biovail also agreed to acquire approximately 2.4 million of additionally issued DepoMed shares for $12.3 million. Biovail has subsequently developed a 1000mg dose of metformin extended release. In April 2004, Depomed and Biovail amended their original license agreement of May 2002. Under the terms of the amended agreement, Depomed will receive royalties on sales of Biovail's 1000mg tablet in the US and Canada. In turn, Biovail acquired access to Depomed's clinical data for the metformin 500mg tablet that will be used to accelerate regulatory filings for Biovail's 1000mg tablet and establish equivalence between the two dosages. Metformin GR is available for partnership in Europe and Asia (Bio-Square-2004, Basel, Switzerland). In April 2004, Depomed and Biovail filed an NDA with the US FDA for the once-daily, extended-release formulation of metformin extended release (Glumetza), 500mg and 1000mg tablets. The 500mg dosage was developed by Depomed using its patented drug delivery GR technology, while Biovail developed the metformin 1000mg dose using its proprietary Smartcoat delivery technology. Depomed completed two double-blind, pivotal, phase III clinical trials with metformin extended release 500mg at 60 sites in the US in more than 1000 patients with type 2 diabetes. In three different dosing regimens, metformin extended release significantly decreased the glycosylated haemoglobin level similarly to that of metformin immediate release. Biovail successfully compared the metformin extended release 1000mg dose with Depomed's 500mg dose in multiple equivalence studies. In these studies, metformin extended release was well tolerated and demonstrated an excellent safety profile in terms of gastrointestinal adverse events. The licensee, Biovail, has submitted an application for metformin extended release with Health Canada. Bristol-Myers Squibb is marketing a proprietary, once-daily extended-release formulation of metformin (Glucophage XR). Several companies are developing controlled-release and extended release formulations of metformin.

Delayed-Action Preparations↗

PubMed2002

Transvaginal and transabdominal extended field-of-view (EFOV) and power doppler EFOV sonography in gynecology: advantages and applications.

OBJECTIVE: To evaluate the possible advantages, applications, and usefulness of real-time transabdominal and transvaginal extended field-of-view sonography combined with power Doppler sonography in gynecology. METHODS: A series of 63 gynecologic patients, referred for preoperative sonographic examination and for whom the examiner thought that extended field-of-view sonography might be helpful in imaging pathologic findings, were selected. Patients were examined with conventional vaginal and abdominal B-mode sonography, extended field-of-view sonography, and power Doppler extended field-of-view sonography. A sonographic system with 3.5- to 7-MHz transducers was used to study and document pathologic findings. RESULTS: Extended field-of-view sonography provided a superior overview of pathologic findings and topography by creating a single image showing the relationship to reference structures. The combination of power Doppler extended field-of-view sonography provided additional information on the perfusion pattern in huge masses. In comparison with conventional sonographic images, the extended field-of-view sonographic images were easier to interpret by the referring or nonexamining physician. A list of proposed gynecologic applications for the use of extended field-of-view sonography was compiled. CONCLUSIONS: The extended field-of-view and power Doppler extended field-of-view sonographic technique provides documentation of surroundings, topographic orientation, and perfusion patterns in large pelvic masses and findings that exceed the limitations of the conventional sonographic sector. The clinical applications and advantages of extended field-of-view and power Doppler extended field-of-view imaging in gynecologic sonography are illustrated.

Abdomen↗

PubMed2002

Detection of extended-spectrum b-lactamases in members of the family enterobacteriaceae at a teaching hospital, Riyadh, Kingdom of Saudi Arabia.

OBJECTIVE: To determine the prevalence of extended spectrum b-lactamase at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia and to compare the ability of the disc diffusion, double disc potentiation methods and the extended-spectrum b-lactamase E test to detect exended-spectrum b-lactamase among enterobacteriaceae. METHODS: This study was undertaken during the time period period January 1 through to September 30 1999, at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia. A total of 187 multiresistant isolates of enterobacteriacae from different clinical specimens were tested for the extended-spectrum b-lactamases. The performance of disc diffusion, double disc potentiation methods using cefotaxime, ceftazidime, ceftriaxone and aztreonamand the extended-spectrum b-lactamase E based on the reduction of the minimum inhibitory concentration of ceftazidime in the presence of clavulanic acid were compared for the detection of extended-spectrum b-lactamase production. RESULTS: Thirty six percent of our isolates produced extended-spectrum b-lactamases. Among these 42% were Klebsiella pneumoniae and 20% were Escherichia coli. Other species of Enterobacteriaceae produced extended-spectrum b-lactamase in low numbers. Disc diffusion method was not suitable for detecting extended-spectrum b-lactamases among the isolates. Double disc potentiation performed comparably well with the extended-spectrum b-lactamases E test. CONCLUSION: Extended-spectrum b-lactamases occurs in Klebsiella pneumoniae and Escherichia coli at a significant number. The use of double disc potentiation method for screening is practical and the extended-spectrum b-lactamase E test with ceftazidime is a useful confirmatory test for extended-spectrum b-lactamase production.

Cross Infection↗

PubMed1997

Extended wear in perspective.

BACKGROUND: Convenience and safety are major motivating factors in the choice of a mode of correction for refractive errors. Extended wear of contact lenses is associated with greater convenience than daily wear, but questions remain concerning the safety and risks associated with this modality. This paper investigates the hurdles that have rendered extended wear an unfavorable option thus far and seeks to identify strategies to overcome these obstacles. METHOD: We review the history of extended contact lens wear, focusing on soft extended wear for cosmetic use. Results of incidence and relative risk studies for the major complications are scrutinized. The factors that are associated with increased risk together with mechanisms which have been proposed on based on scientific research are analyzed to derive strategies for preventing adverse reactions in extended wear. RESULT: Infectious keratitis associated with extended wear of contact lenses has been identified by the community as a major issue, although the degree of concern may be disproportionate. Current perceptions of the relative risk of extended wear versus daily wear in the context of the risk for nonwearers may be misplaced, and the role of eye closure versus consistency and duration of wear remains open to debate. In the minds of practitioners and patients, other adverse reactions may be of greater significance in rejecting extended wear. Nonetheless, the potential extent of injury from infection demands attention. Studies collectively attest that corneal hypoxia during extended wear is a potential causative mechanism in infectious keratitis, suggesting that the provision of higher oxygen levels to the cornea will reduce morbidity rates from this unwanted complication. However, the issues of stagnation of the post-lens tear film during eye closure, mechanical properties of the lens, and lens movement remain unresolved and may prove to be contributing factors to adverse responses. CONCLUSIONS: Attention to oxygen permeability and mechanical properties of soft contact lenses should solve the remaining problems with extended wear. Materials currently under development promise to meet at least some of the desired properties and may lead to the long-awaited advent of safe extended wear.

Animals↗

PubMed2003

Clarithromycin extended-release tablet: a review of its use in the management of respiratory tract infections.

UNLABELLED: Clarithromycin is an orally active, advanced-generation macrolide that has been reformulated as an extended-release tablet (Biaxin) XL Filmtab allowing convenient once-daily administration. The reformulation is intended to improve patient compliance and the tolerability of the drug. Although maximum plasma clarithromycin concentrations are lower and reached later with the extended-release tablets than with the immediate-release tablets, the two formulations are bioequivalent with respect to the area under the plasma concentration-time curve. Bioequivalence is also achieved between the formulations for the microbiologically active metabolite, 14-hydroxy-clarithromycin. Two randomized trials in patients with acute exacerbations of chronic bronchitis (AECB) showed that a 7-day course of clarithromycin extended-release 1000 mg once daily produced clinical cure rates of 83% and 85% and bacteriologic cure rates of 86% and 92% at the test-of-cure study visit. Similar rates of cure were achieved with a 7-day course of twice-daily clarithromycin immediate-release and with a 10-day course of twice-daily amoxicillin/clavulanic acid.A 7-day course of clarithromycin extended-release 1000 mg once daily produced clinical and bacteriologic cure rates of 88% and 86%, respectively, in patients with community-acquired pneumonia (CAP). Similar cure rates were achieved in recipients of once-daily levofloxacin in the same trial. In patients with acute maxillary sinusitis, a 14-day course of either once-daily clarithromycin extended-release or twice-daily clarithromycin immediate-release produced statistically equivalent clinical cure rates of 85% and 79%, respectively. Both treatment groups achieved similar rates of radiographic success and resolution of sinusitis. Recent results indicate that clarithromycin extended-release 500 mg once daily for 5 days is also effective in the treatment of patients with streptococcal pharyngitis/tonsillitis and in the treatment of AECB. The most frequently reported drug-related events with clarithromycin extended-release were abnormal taste (7% incidence), diarrhea (6%) and nausea (3%). Most adverse drug reactions were of a mild and transient nature. In comparative clinical trials, clarithromycin extended-release had an improved gastrointestinal tolerability profile compared with the immediate-release formulation. In addition, clarithromycin extended-release was better tolerated than amoxicillin/clavulanic acid and as well tolerated as levofloxacin. Further studies are required to assess the cost-effectiveness ratio of clarithromycin relative to comparator antibacterial agents. CONCLUSION: Clarithromycin extended-release is an effective treatment for AECB, CAP, acute maxillary sinusitis, and pharyngitis (although not approved for the latter in the US), and is administered in a convenient dosage regimen that has the potential to encourage good compliance. The reformulation modulates clarithromycin absorption kinetics thereby improving tolerability. Therefore, clarithromycin extended-release provides a useful option for the treatment of specific respiratory tract infections.

Administration, Oral↗

PubMed1993

Comparison of different extenders for the cryopreservation of Atlantic salmon spermatozoa.

Fifteen extenders were produced by adding dimethyl sulfoxide (DMSO) at 8, 10 or 12% of diluent volume to 5 diluents. All extenders were cooled to 4 degrees C. Pooled Atlantic salmon (Salmo salar) semen with greater than 90% progressive motility was kept at 4 degrees C and added to each extender so that the semen was diluted 1:3 (semen:extender). The equilibration time was less than 5 minutes at 4 degrees C. The extended semen was loaded into 0.5-ml straws and was cooled from 4 degrees C to -90 degrees C at a rate of 30 degrees C per minute. The straws were then plunged into liquid nitrogen for storage. Fluorometry was used to determine the viability of the semen in each of the extenders after freezing and thawing. Cryopreservation of Atlantic salmon semen in Extender 3 (0.137 M NaCl, 0.011 M KCl, 0.004 M Na(2)HPO(4).7H(2)O, 7.5 g/l L-alpha-lecithin and 12% dimethyl sulfoxide) and Extender 12 (0.100 M KHCO(3), 0.0065 M reduced glutathione, 0.125 M sucrose and 12% dimethyl sulfoxide) resulted in significantly (P<0.05) lower percentages of dead spermatozoa than for the other extenders. Furthermore, there was a significantly (P<0.05) lower percentage of dead cells in Extender 3 than in Extender 12.

Journal Article↗

PubMed2005

Ultramicroscopic and biochemical changes in ram spermatozoa cryopreserved with trehalose-based hypertonic extenders.

The ability of a range of extenders to cryopreserve ram spermatozoa was tested. The extenders were modified by the inclusion of citrate, Tris buffer, trehalose, and EDTA. Ejaculates from three Pampinta rams were evaluated and pooled at 30 degrees C. The semen was diluted to contain 1 x 10(9) cells/mL, cooled to 5 degrees C, loaded into 0.25-mL straws, frozen and stored in liquid nitrogen. Evaluation was based on the hypoosmotic swelling test (HOS test), electron microscopy, and biochemical parameters such as lipid peroxidation and reduced and total glutathione levels, all measured after thawing. The HOS test indicated that the percentage of intact plasma membranes after freezing and thawing was significantly higher for the hypertonic extender containing trehalose (T), compared with an extender containing trehalose+EDTA (TE) or an isotonic Tris extender (B) (p < 0.05). Membrane evaluation by ultramicroscopy also indicated better sperm cryopreservation in extender T compared with the others, and there was a significant reduction in the number of damaged membranes (27%, p < 0.0002). The level of reduced glutathione was significantly higher after sperm cryopreservation in either hypertonic diluent (T and TE) with respect to the isotonic extender B, immediately after thawing (12%) and after a 3-h post-thawing thermotolerance test at 37 degrees C (17%, p = 0.007). Total glutathione levels did not show statistical differences among the extenders. After 3h post-thawing incubation at 37 degrees C, lipid peroxide levels in spermatozoa were statistically lower for T than TE (35%) or isotonic extender B (44%) (p = 0.002). Taken together these results indicate a reduction in the oxidative stress provoked by freezing and thawing when semen is cryopreserved in extender T. The antioxidant properties of extender T may be related to its effectiveness in membrane cryopreservation.

Animals↗

PubMed2005

Extended donor criteria for lung transplantation--a clinical reality.

OBJECTIVE: Standard lung donor criteria have been established on opinions and individual experiences rather than on existing evidence. Since the scarcity of donor organs is one of the major limitations to lung transplantation, extension of donor lung criteria might considerably increase the donor pool. This study therefore evaluates the outcome, achieved with the use of extended donors versus standard donors and aims to redefine lung donor criteria. METHODS: We performed a retrospective analysis of 98 consecutive primary lung transplantations from 94 donors from 1/2001 to 12/2002. Donors were classified as extended if they fulfilled at least one criteria: age >55 years, PaO(2) at FiO(2)/PEEP 5 <300mmHg, tobacco history >20 pack years, inhalative drug abuse, presence of infiltration on chest X-ray or purulent secretions at bronchoscopy. Recipients were stratified in two groups according to whether they received a 'standard' or 'extended' organ. Postoperative complications, extubation time, ICU and hospital stay and survival were compared. RESULTS: Twenty-three (24.5%) donors were extended. Twenty-six recipients (26.55%) received organs from extended donors. Differences in intubation times (12+/-2 days standard vs. 14+/-5 days extended, P=0.70), ICU stay (16+/-2 days standard vs. 18+/-5 days extended, P=0.74) and hospital stay (38+/-4 days standard vs. 40+/-6 days extended, P=0.71) were not statistically significant. Postoperative bleeding rates were comparable (n=14 standard vs. n=3 extended) as well as bronchial anastomotic complications (n=7 standard vs. n=3 extended). Three months survival was 88.89% in the standard group vs. 92.31% in the extended group. One year survival is comparable as well with 81.94 vs. 84.62%, respectively. CONCLUSIONS: The use of lung donors who fail to meet standard criteria does not impair short and medium term results compared to standard lung donors. The impact on long term development of BOS has yet to be evaluated. The strict application of standard lung donor criteria excludes a considerable number of lungs potentially suitable for transplantation, thus liberalisation of donor criteria might help to overcome donor shortage.

Adult↗

PubMed2006

The utility of extended outpatient civil commitment.

OBJECTIVE: This study considers three hypotheses regarding the impact of extended involuntary outpatient commitment orders on services utilization. METHOD: Service utilization of Victorian Psychiatric Case Register (VPCR) patients with extended (> or =180 day) outpatient commitment orders was compared to that of a diagnostically-matched treatment compliant group with similarly extended (> or =180 day) periods of outpatient care (N=1182)--the former receiving care during their extended episode on an involuntary basis while the latter participated in care voluntarily. Pre/post first extended episode mental health service utilization was compared via paired t tests with individuals as their own controls. Logistic and OLS regression as well as repeated measures ANOVA via the GLM SPSS program and post hoc t tests were used to evaluate between group and across time differences. RESULTS: Extended episodes of care for both groups were associated with subsequent reduced use of hospitalization and increases in community treatment days. Extended orders did not promote voluntary participation in the period following their termination. Community treatment days during the extended episode for those on orders were raised to the level experienced by the treatment compliant comparison group during their extended episode and maintained at that level via subsequent renewal of orders throughout the patients' careers. Approximately six community treatment days were required for those on orders to achieve a one-day reduction in hospital utilization following the extended episode. CONCLUSION: Outpatient commitment for those on extended orders in the Victorian context enabled a level of community-based treatment provision unexpected in the absence of this delivery system and provided an alternative to hospitalization.

Adult↗

PubMed2003

In vitro and in vivo comparison of egg yolk-based and soybean lecithin-based extenders for cryopreservation of bovine semen.

Semen diluents containing egg yolk as a cryoprotectant may pose hygienic risks and are difficult to standardize. Although a new generation of semen diluents free of animal ingredients is available, egg yolk-containing extenders are still widely used for cryopreserving semen. We compared the effects of using different extenders on bovine sperm function in vitro and on fertility in vivo. A soy lecithin extender (SL; AndroMed) and an egg yolk-containing (TRIS-EY) extender were tested. No differences (P>0.05) were detected between the two extenders for sperm-zona pellucida binding capacity (HZI=115+/-13). Assessment of the inducibility of the acrosome reaction with progesterone showed no differences (P>0.05) between extenders for live acrosome-reacted sperm (15+/-2.36 and 14.42+/-2.02%, respectively, for SL and TRIS-EY). However, post-thaw sperm motility was significantly lower (P<0.05) when semen was extended in the TRIS-EY diluent. Field trials revealed that nonreturn rates of SL-extended semen showed significantly higher insemination success (P<0.0001) compared with the nonreturn rates for the TRIS-EY extender (70.45 and 67.85%, respectively). We suggest that consistent with quality standards that should be required for cryoprotectant media and because of the superior quality of the egg yolk-free extender, a defined soybean lecithin-containing diluter might be the better choice as a semen extender in the future.

Acrosome↗

PubMed2000

Proposed performance criteria for extended wear contact lenses.

The introduction of silicone-hydrogel materials has changed expectations for the response to contact lenses used in extended wear. In keeping with this technology shift, we have re-evaluated the criteria by which practitioners judge the performance of extended wear lenses. Attendees at the 1999 Annual Clinical Conference of the British Contact Lens Association were surveyed. The proportion of respondents who considered it appropriate to fit selected patients with conventional, disposable and silicone-hydrogel soft lenses for extended wear was 63%, 67% and 86%, respectively. Only 11% of respondents did not fit extended wear because of personal experience with infectious keratitis, and over 50% relied on educators' advice in avoiding this practice. Fifteen per cent of practitioners reported fitting extended wear on occasions. Ninety-five per cent of respondents thought that the relative risk of infectious keratitis with daily wear compared with no lens wear should be ten or less, which was reduced to 60% when it was revealed that the current relative risk is estimated to be 60. A strong preference for a relative risk of infection with extended wear compared to daily wear of less than five times was indicated, which is consistent with current estimates. A minority of respondents were prepared to accept an overnight oedema level of over 6% with extended wear, although silicone-hydrogel materials have been shown to induce less than 4%. A wide variety of microcyst responses were considered reasonable, with many respondents accepting up to 40 per cornea; again, this result contrasted with early research data suggesting a level of 10 microcysts or less occurring with silicone-hydrogel materials. Interpretation of these findings has led us to the following proposals for safe extended wear: (i) extended wear fitting should preferably be done with silicone-hydrogel materials, rather than conventional hydrogels, where the available parameter ranges overlap; (ii) the relative risk of corneal infection with extended wear compared to daily wear should be two to five times, providing the relative risk of daily wear compared to the no lens wear'situation is reduced to 20 times, and (iii) extended wear lenses should produce an average of no more than 4% overnight oedema and no more than 10 microcysts per eye in the long term.

Journal Article↗

PubMed1999

Asbestos induction of extended lifespan in normal human mesothelial cells: interindividual susceptibility and SV40 T antigen.

Normal human mesothelial cells from individual donors were studied for susceptibility to asbestos-induction of apoptosis and generation of an extended lifespan population. Such populations were generated after death of the majority of cells and arose from a subset of mesothelial cultures (4/16) whereas fibroblastic cells (5/5) did not develop extended lifespan populations after asbestos exposure. All mesothelial cultures were examined for the presence of SV40 T antigen to obtain information on (i) the presence of SV40 T antigen expression in normal human mesothelial cells and (ii) the relationship between generation of an extended lifespan population and expression of SV40 T antigen. Immunostaining for SV40 T antigen was positive in 2/38 normal human mesothelial cultures. These cultures also had elevated p53 expression. However, the two isolates expressing SV40 T antigen did not exhibit enhanced proliferative potential or develop an extended lifespan population. Asbestos-generated extended lifespan populations were specifically resistant to asbestos-mediated but not to alpha-Fas-induced apoptosis. Deletion of p16Ink4a was shown in 70% of tumor samples. All mesothelioma cell lines examined showed homozygous deletion of this locus which extended to exon 1beta. Extended lifespan cultures were examined for expression of p16Ink4a to establish whether deletion was an early response to asbestos exposure. During their rapid growth phase, extended lifespan cultures showed decreased expression of p16Ink4a relative to untreated cultures, but methylation was not observed, and p16Ink4a expression became elevated when cells entered culture crisis. These data extend the earlier observation that asbestos can generate extended lifespan populations, providing data on frequency and cell type specificity. In addition, this report shows that generation of such populations does not require expression of SV40 T antigen. Extended lifespan cells could represent a population expressing early changes critical for mesothelioma development. Further study of these populations could identify such changes.

Adult↗

PubMed2005

Effects on the quality of frozen-thawed alpaca (Lama pacos) semen using two different cryoprotectants and extenders.

AIM: To evaluate two extenders and two cryoprotectant agents (CPA) for alpaca semen cryopreservation. METHODS: Semen samples were obtained from four adult alpacas (Lama pacos) and frozen using extender I (TRIS, citrate, egg yolk and glucose) or extender II (skim milk, egg yolk and fructose), each containing either glycerol (G) or ethylene glycol (EG) as CPA. Consequently, four groups were formed: 1) extender I-G; 2) extender I-EG; 3) extender II-G; and 4) extender II-EG. Semen was diluted in a two-step process: for cooling to 5 degrees (extenders without CPA), and for freezing (extenders with CPA). Viability and acrosome integrity were assessed using trypan blue and Giemsa stains. RESULTS: When compared, the motility after thawing was higher (P >0.05) in groups II-EG (20.0% +/- 6.7%) and II-G (15.3 % +/- 4.1% ) than that in groups I-G (4.0 % +/- 1.1%) and I-EG (1.0 % +/- 1.4%). Viable spermatozoa with intact acrosomes in groups II-EG (18.7 % +/- 2.9%) and II-G (12.7 % +/- 5.9%) were higher than that in groups I-G (5.7% +/- 1.5%) and I-EG (4.0% +/- 1.0%). CONCLUSION: The skim milk- and egg yolk-based extenders containing ethylene glycol or glycerol to freeze alpaca semen seems to promote the survival of more sperm cells with intact acrosomes than the other extenders.

Animals↗

PubMed1987

Effects of extender and insemination dose on postthaw quality and fertility of bovine sperm.

Quality and fertility of sperm extended in egg yolk-Tes-Tris were compared with those of sperm in egg yolk-citrate and homogenized milk extenders. Extended semen was frozen in .5-ml plastic straws at 11, 15, 17, or 22 X 10(6) sperm per insemination dose. Laboratory evaluations at 0, 1, 2, and 4 h after thawing semen utilized four tests of spermatozoal quality. Use of egg-yolk citrate extender resulted in a higher percentage of progressively motile sperm as determined visually at 0 h after thawing than use of egg yolk-Tes-Tris or homogenized milk extenders. Sperm extended in egg yolk-citrate had 18% lower activity of bound amidase at 0 h than sperm extended in egg yolk-Tes-Tris. The 75-d nonreturn rates were affected by insemination dose but not be extender or the interaction of extender and insemination dose. Fertility was lower after insemination of 11 X 10(6) sperm than for pooled data for the three higher insemination doses (64 vs. 68%). Based on all data, postthaw quality of sperm processed in the one-step egg yolk-Tes-Tris extender was similar to that for sperm extended in egg yolk-citrate or homogenized milk.

Animals↗

PubMed2006

[Dose "extended" surgery for pancreatic head adenocarcinoma have survival impact?].

Adenocarcinoma of the pancreas is the most difficult to treat, and the prognosis, even if curative resection is possible, is dismal. Improving survival in this intractable disease is a challenging issue. Most Japanese surgeons have stressed that resection with extended lymphadenectomy and autonomic nerve dissection (extended surgery) can offer a better chance of long-term survival. On the other hand, surgeons in Western countries are skeptical about extended surgery and have preferred resection without extended lymphadenectomy (standard surgery). Two randomized controlled trials (RCTs) on "standard vs. extended surgery for pancreatic head adenocarcinoma" were reported in 1998 from Italy and in 2002 from USA. Those two RCTs demonstrated that extended surgery did not improve patient survival; however, they had little impact on Japanese surgeons because the extended surgery used in those RCTs were not "true" extended surgery. Thereafter, one RCT was conducted in Japan in which extensive lymphadenectomy including paraaortic node and complete resection of autonomic nerves around the common hepatic and the superior mesenteric arteries were performed in extended surgery. Unexpectedly, the results showed that the survival rates were similar between extended and standard surgeries, compatible with the results of the Western RCTs. We should therefore conclude that extended surgery does not improve survival for patients with pancreas head adenocarcinoma.

Adenocarcinoma↗

PubMed1999

Adverse events with extended wear of disposable hydrogels: results for the first 13 months of lens wear.

OBJECTIVE: To determine the type and incidence of adverse events seen in the first 13 months of extended wear from a prospective clinical trial involving the use of disposable hydrogels on a 6-night extended wear and replacement schedule. DESIGN: A prospective, noncomparative clinical trial. PARTICIPANTS: Three hundred thirty subjects were enrolled in the study from March 1993 to August 1996 and commenced in extended wear. The subjects were new contact lens users with ages ranging from 16 to 39 years and refractive errors from -1.00 to -6.50-diopter (D) sphere with cylindrical component less than 1.0 D. INTERVENTION: Disposable hydrogel lenses on a 6-night extended wear and replacement schedule. MAIN OUTCOME MEASURES: To determine the incidence of adverse events in the first 13 months of lens wear with the use of disposable hydrogels on an extended wear schedule. In addition, corneal infiltrative events observed with lens wear were classified based on their presenting signs and symptoms. RESULTS: A total of 137 adverse events were seen in 102 subjects in the first 13 months of extended wear. The type of adverse events and the incidence per 100 patients per year of lens wear were as follows: corneal infiltrative events (44.4 events), contact lens papillary conjunctivitis (6.4 events), neovascularization and corneal wrinkling (1.7 events each), corneal striae and superior epithelial arcuate lesions (1.3 events each), and blepharokeratoconjunctivitis (0.4 event). Viral keratoconjunctivitis was also observed (0.8 event). The corneal infiltrative events were further subclassified as follows: contact lens-induced peripheral ulcers (13.6 events), contact lens-induced acute red eyes (12.3 events), infiltrative keratitis (9.7 events), and asymptomatic infiltrative events (8.9 events). There were no events of infectious keratitis. Except for all events of contact lens-induced peripheral ulcers and two isolated events of infiltrative keratitis that resulted in scarring, all of the corneal infiltrative events resolved without sequelae. None of the events caused any loss of best-corrected visual acuity. CONCLUSIONS: Based on the observations from the first 13 months of extended wear in the trial, the majority of the complications associated with extended wear of disposable hydrogels are corneal infiltrative events. No events of microbial keratitis were seen in the first 13 months of extended wear. None of the events were associated with loss in best-corrected visual acuity. Clearly, frequent and regular disposing of lenses does not eliminate adverse effects, and better materials and designs are required for extended wear to be a successful method.

Adolescent↗

PubMed2000

Effects of RGP lens extended wear on glucose-lactate metabolism and stromal swelling in the rabbit cornea.

PURPOSE: To assess the chronic effects of rigid gas-permeable (RGP) contact lenses on corneal swelling and glucose-lactate metabolism in the rabbit cornea during 1 month of continuous extended wear and to establish the relationship between these effects and the oxygen transmissibility (Dk/L) of the test lens polymer. METHODS: Four RGP lenses of varying Dk/L were tested in 8 rabbits per test group (left eyes served as controls). After 7 days and 1 month extended wear, the concentrations of lactate and glucose in the corneal epithelium, stroma and aqueous humor were determined by enzyme assay; and epithelial and stromal ATP concentrations were separately measured by bioluminescence techniques. Corneal thickness was measured at a standard morning time by ultrasonic pachymetry before and after 1, 7, 15 days and 1 month extended wear. RESULTS: After 7 days and 1 month extended wear, generalized decreases were found in aqueous humor lactate levels for all test lenses, while concomitant increased aqueous glucose concentrations were observed. Total epithelial lactate levels correlated inversely with decreasing Dk/L levels for lower oxygen transmissible lenses (R = 0.951, P = 0.0051); and remained unchanged after extended wear of the hyper-oxygen transmissible Dk/L 125 test lens. By contrast, stromal lactate levels consistently decreased at all time points measured forextended wear of all test lenses. As expected, both epithelial and stromal ATP concentrations simultaneously decreased in extended wear. Overnight corneal swelling values after 24 hours wear of Dk/L = 27, 43, 70 and 125 test lenses were increased by 9.8, 7.1, 5.5, and 5.2% while persistent (residual) stromal swelling after one month extended wear was 16.8, 10.1, 8.6, and 5.6% respectively, in excess of baseline values. CONCLUSIONS: Chronic RGP contact-lens induced hypoxia is associated with altered glucose-lactate metabolism in the cornea and aqueous humor with excess production of increased levels of lactate in the epithelium for lower Dk/L test lenses, but decreased lactate concentration in the stroma and aqueous humor. Extended wear of the hyper-oxygen transmissible test lens (Dk/L = 125) however, produced no increase in epithelial lactate levels. Expected lens-induced decreases in epithelial and stromal ATP were not dependent on lens-oxygen transmissibility. Despite the persistence of lower than normal stromal levels of lactate during 1 month of extended wear for all test lenses, residual corneal swelling values remained consistently elevated above baseline values. Taken together, these data establish that increased stromal lactate accumulation cannot account for persistent stromal edema in chronic extended wear of RGP lenses; and that this effect appears to be independent of lens-oxygen transmissibility and may thus represent the prolonged mechanical effect of lens wear itself.

Adenosine Triphosphate↗

PubMed1995

Effect of various extenders and taurine on survival of stallion sperm cooled to 5 degrees C.

Stallion semen was diluted in five different extenders (dimitro-poulus onze (Dimitro's), Kenney's modified tryode (Kenney's), modified INRA82 (INRA82), egg yolk-citrate-taurine (Citrate) and EZ-Mixin) and evaluated for motility after cooling and storage at 5 degrees C for 0, 24, 48, 72 and 96 h. EZ-Mixin extender was used as control while 70 and 100 mM of taurine were added to Dimitro's, Kenney's and INRA82 to study its effect under conditions of storage at 5 degrees C and varying processing modifications. Motility in INRA82 was 57.0, 58.4, 61.1, and 56.1% after 24, 48, 72 and 96 h, respectively and was higher (P < 0.05) than in other extenders after 48, 72, and 96 h. Motility decreased over time in Dimitro's (P < 0.05) and Kenney's (P < 0.01). Motility in INRA82 and EZ-Mixin decreased (P < 0.05) after 24 h and then remained unchanged until 96 h. In taurine (70 mM) containing extender Citrate, motility decreased throughout storage. Motility in INRA82 and Kenney's with taurine decreased (P < 0.05 and P < 0.01, respectively) after 48 h, and then remained stable until 96 h only in INRA82 with taurine. Motility in INRA82 with taurine was higher (P < 0.05) than in Citrate throughout incubation, whereas motility in INRA82 with taurine was higher than in EZ-Mixin and Kenney's with taurine after 24 and 48 h, respectively. Motility in INRA82 and Kenney's with taurine improved (P < 0.05) when osmotic pressure was increased with taurine (100 mM) but not when osmotic pressure was increased with Na (+) and K (+) salts. Motility was always higher (P < 0.01) in taurine (70 mM or 100 mM) containing extenders than in non-taurine extenders, Dimitro's, INRA82, and Kenney's, when sperm were incubated for 24 h at 5 degrees C in these extenders, then washed and incubated at 39 degrees C in Sp-TALP for 12 or 24 h. In conclusion 1) INRA82 was a better extender than the other extenders tested. 2) inclusion of taurine (100 mM) in INRA82 and Kenney's improved sperm survival until 96 and 48 h, respectively, and 3) sperm preincubation for 24 h in taurine containing extenders resulted in better sperm survival when washed and stored in Sp-TALP for further 12 or 24 h.

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