Years Of Continuous Use Research Articles

Anti-reflux surgery in the laparoscopic era

The introduction of laparoscopic anti-reflux surgery has led to a renewed interest in the operative treatment of gastro-oesophageal reflux disease (GORD). Three groups of patients can be identified who are particularly suited to laparoscopic anti-reflux surgery. Failure to respond to medical treatment has been historically the main determinant for those referred for anti-reflux surgery. With the availability of modern anti-secretory drugs most patients with chronic GORD can control their symptoms adequately by these means. Even effective medical therapy, however, is not without problems. In many patients rapid and consistent relapse of symptoms and oesophagitis occurs on cessation of therapy. Some of these patients do not want to be reliant on a form of medication that has yet to firmly establish its record for safety over many years of continued use. A second readily identifiable group of patients are those who are often described as ‘volume refluxers’. They are bothered by persistent fluid regurgitation despite adequate control of their heartburn with acid suppressive drugs. Third there are those individuals who develop oesophageal strictures and those with Barrett's oesophagus and concomitant reflux symptoms and also those with respiratory complications associated with presumed aspiration of gastric juice into the pharynx and into the respiratory tree.The low morbidity associated with laparoscopic surgery that has been achieved in the best modern series means that the pendulum may swing back to surgery and therefore it is even more important that the right operation (fundoplication) is done for the right patient. Failure to create an adequate crural repair behind the wrap is associated with a risk of early post-operative para-oesophageal herniation and proximal wrap migration. The question of tailored anti-reflux surgery based on the pre-operative motor function of the body of the oesophagus is widely applied, although the scientific basis for these selective approaches is rather weak. Partial fundoplication seems to be associated with very low rates of dysphagia and of gas bloat. Assessment of the post-operative result should ideally be done by an independent observer and should consider not only traditional outcome measures but also the impact of surgery on the quality of the patient's life. Investigations on the cost effectiveness of these surgical therapeutic strategies suggest important benefits of surgery, which should be incorporated into the clinical decision process when assessing different long-term management alternatives for patients with chronic GORD.

Vibration and Noise of Small Implements for Soil Tillage

Small cultivators can represent the main or the sole mechanical resource for agriculture in many countries. For such constant use, their ergonomic characteristics can assume a great importance. In this paper, the vibration and noise of some of these implements—one of which is made in China—were examined. The acceleration transmitted from the handle and the noise level at the user's ear were measured during soil tillage, according to International standards.The results indicate that in 10% of the exposed population, vascular disorders of the hand (Vibration White Finger) can appear after three years of continuous use of these machines, under usual working conditions. The level of noise at the worker's ear should not involve an appreciable risk for hearing after 10 yr of use. For the noise levels experienced on the majority of the implements examined, the domestic and European directives require that the worker need only receive appropriate information about the problems due to the noise. In view of the introduction and promotion of these implements in China and in the developing countries, it is necessary at least to reduce the vibration transmitted to the user's hands, by providing adequate insulating systems for the handle.

Health effects of long‐termuse of the intrauterine levonorgestrel‐releasing system, A follow‐up study over 12 years of continuous use

This report comprises women from one center, who all participated in a larger European multi-center study, which included 2758 healthy women, of whom 1821 were randomly allocated to the levonorgestrel-releasing intrauterine system (Lng-IUS) and 937 to a copper-IUD (Nova-T). At the end of the 5 year study period, 109 of the 300 women, who originally were allocated to the Lng-IUS at this center, were still using the Lng-IUS. The women were offered the opportunity to continue the Lng-IUS and 100 women chose to do so. After a total period of almost 7 years of continuous use, a second Lng-IUS was offered and 82 of the women chose to start a second segment of Lng-IUS use. After another 5 years, 69 of the women were fitted with their third Lng-IUS. These 82 women were examined yearly throughout the study period and bleeding pattern, hemoglobin, weight, blood-pressure, general well-being and intercurrent disease were analyzed to assess long-term effects. No pregnancy occurred during the follow-up. One case of partial expulsion occurred and one case of pelvic inflammatory disease. Seventy-seven percent of the women did not report any health problems at all during the entire follow-up period of 13 years. At the end of the second period with the Lng-IUS, 60% reported amenorrhea, 12% infrequent, scanty bleeds and 28% regular, scanty bleeds. As a consequence, the hemoglobin values increased, with a mean increase, after 12-13 years, being 1.35 g/dl. Blood pressure increased slightly and body weight increased with a mean increase of 0.49 kg/year. Seven women became postmenopausal during the follow-up and started estrogen replacement therapy with the Lng-IUS in situ. This follow-up study suggests that the Lng-IUS remains a safe and effective method of contraception, allowing women prolonged relief of menstrual problems, and for women in their late reproductive years, offering a convenient and bleeding-free transition into the menopause.

Health effects of long-termuse of the intrauterine levonorgestrel-releasing system, A follow-up study over 12 years of continuous use

Health effects of long-termuse of the intrauterine levonorgestrel-releasing system, A follow-up study over 12 years of continuous use

Frequency, Causes, and Outcome of Home Ventilator Failure

The safety of home ventilators has been questioned. We collected data to study the following: frequency of home ventilator failure, apparent causes for the failure or malfunction, and adverse consequences following the failure. Information on all requests to correct home ventilator failures reported to a home respiratory equipment vendor was collected prospectively between November 1991, and November 1992. There were 150 ventilator-assisted patients aged 2 to 77 years; 44 were < or = 18 years. They received 841,234 h of home mechanical ventilation (average, 15.4 h/d per ventilator-assisted patient). There were 189 reports of home ventilator failure. Defective equipment or mechanical failure was found in only 39% (73 reports), equivalent to one home ventilator failure for every 1.25 years of continuous use. Other causes of ventilator failure included the following: improper care, damage, or tampering with the ventilator by caregivers (13%), functional equipment improperly used by caregivers (30%), and equipment functional but the patient's condition changed, mimicking ventilator failure (3%). No problem could be identified in 16%. The following actions were required: ventilator replacement (44%), repair of a defective part (6%), replacement of a functioning ventilator for psychological comfort (14%), ventilator adjustments made (21%), caregiver reeducation (7%), caregiver anxiety or distress reduced (3%), and no action required (4%). Hospitalization was required only in two cases (1%). No adverse outcomes, deaths, or serious injuries were associated with home ventilator failure. We conclude that in 150 patients requiring home mechanical ventilation, ventilator failure occurred relatively infrequently, and there were no adverse outcomes as a result of equipment failure at home. We speculate that equipment failure is not a frequent or serious problem for ventilator-assisted patients treated at home.

SHORT-TERM SAFETY AND EFFICACY OF AN APPETITE SUPPRESSANT IN CHILDHOOD OBESITY • 410

Child-onset obesity is a serious individual and public health problem. Existing therapy using diet, exercise, and behavior modification (DEBM) has had limited success, particularly for low-income families with limited resources and access. Adult studies show appetite suppressant medication (ASM) is safe and effective, but there are no adequate studies in children. We performed a randomized, double-blind, placebo-controlled, crossover study with good statistical power, to see if ASM (phentermine 15 mg orally once every morning before breakfast) with DEBM is safe and effective in children ages 7-12 with body mass index (BMI) > 95th percentile for age and sex. 35 patients have completed the study. Each received weekly extensive DEBM beginning at least 2 weeks before ASM/placebo and continuing throughout the study. Group 1 was treated with ASM for 2 months then placebo for 2 months, Group 2 was treated with placebo then crossed over to ASM. The BMI change was-1.24 kg/M2 for Group 1 and -0.23 for Group 2 (P < 0.0008, t-test) during the first 2 months before crossover. After crossover, the change in BMI was +0.91 for Group 1 and -0.69 for Group 2 (P < 0.0004). BMI changes were also significant controlling for age, sex, and height (i.e., after conversion to z-scores). Extensive monitoring of mood, cognition, and school performance using the Teacher and Parent Child Behavior Checklist, Profile of Mood States, and Continuous Performance Test, pre-, during, and after ASM showed no adverse effects. Height velocity was unaffected, and troublesome side-effects were minimal. This study shows that ASM is safe and effective short-term, and appears to be more potent than DEBM. Successful completion of this short-term study clears the way for long-term trials similar to those completed in adults showing safety and efficacy for up to 4 years of continuous use.

Treatment of photodamage with topical tretinoin: An overview

Topical administration of tretinoin has proved to be effective in treating clinical signs of photodamaged skin. In large-scale, double-blind, placebo-controlled, 6-month trials, 0.05% tretinoin emollient cream (Renova, Retinova) reduced fine wrinkles and skin roughness, and it produced histologic changes such as epidermal thickening, increased granular layer thickness, stratum corneum compaction, and decreased melanin content. Smaller changes were also observed at lower tretinoin concentrations. Continued for another 6 months, 0.05% tretinoin emollient cream produced some additional clinical improvement but the histologic changes observed in the epidermis (with the exception of melanin content) regressed toward baseline, raising questions as to what was responsible for the clinical improvement. After 12 months of treatment, there were additional signs of tissue normalization including deposition of new collagen in the papillary dermis and ultrastructural evidence of dermal reconstruction with improvement in the dermoepidermal junction and correction of keratinocyte degeneration, changes that presumably relate directly to tretinoin's mechanism of action. There was no suggestion of cytologic atypia in these studies or in biopsy specimens obtained after up to 4 years of continued use. Mild to moderate dermatitis was the only common adverse reaction to tretinoin use. Percutaneous tretinoin absorption is low, raising plasma levels by amounts that are negligible compared with the normally low endogenous tretinoin levels. No teratogenic effects have been observed in retrospective studies of topical tretinoin application during the first trimester of pregnancy. Thus, topical tretinoin is safe and effective in the treatment of photodamage. (J Am Acad Dermatol 1997;36:S27-S36.)

Systemic retinoid medication and periodontal health in patients with Papillon-Lefèvre syndrome.

Periodontal health in relation to systemic retinoid medication was evaluated retrospectively in patients with Papillon-Lefèvre Syndrome (PLS). The material consisted of 18 children/young adults ranging from 8 to 28 years of age, all with a confirmed diagnosis of PLS. 9 participants, comprising a medication group, had been on long-term (range 1.5-9 years) retinoid medication for their cutaneous lesions. The remaining 9 served as controls. Regardless of whether or not retinoid medication was received, every patient experienced an early and devastating periodontitis, with atypical edematous and erythematous gingiva, suppuration from deep gingival pockets and premature loss of teeth. No correlation could be found between the severity of skin involvement and the severity of periodontal involvement. An improvement with age could be seen for the cutaneous lesions but not for the periodontal condition. Systemic medication with retinoids had a favorable therapeutic effect on cutaneous lesions, and no severe complication/side effect could be seen after several years of continuous use. However, from the results of this study it can be concluded that, at least in a situation with poor compliance of daily oral home-care, no positive effect on the periodontal health in patients with PLS could be seen by the retinoid medication.

The Virgin Islands desalination experience

A description of Virgin Islands climatic conditions and desalination history are presented. Installation of IDE multi-effect plants by the Water and Power Authority solved previous problems, and the plants are operating above rated capacity. The tubes are made of aluminium alloy and acid cleaning is required only after 8 years of continuous use.

Safety and efficacy of a combined oral contraceptive: Gestodene 75 μg plus ethinyl estradiol 30 μg in Mexican women

An open prospective clinical trial designed to evaluate the efficacy and safety of the combined hormonal oral contraceptive (OC) containing 75 micrograms gestodene plus 30 micrograms ethinyl estradiol was undertaken in a Mexican population. Sixty-nine healthy women of reproductive age took part in the study for a total of 627 woman-months of observation. The combination of gestodene and ethinyl estradiol proved its effectiveness in preventing pregnancy during the study. Side-effects were minimal and regular endometrial bleeding patterns were observed during one year of continuous use of this OC preparation. The discontinuation rate for medical reasons was 11.6% at one year. Among a sample of 10 women, the gestodene/ethinyl estradiol combination did not induce significant changes in the serum concentration of total cholesterol and LDL cholesterol after 12 months of continuous administration. An increase in serum triglycerides and HDL cholesterol was observed; this effect could be attributed to a lack of androgenic and/or the intrinsic estrogenic behavior of gestodene. It can be concluded that this preparation is highly effective as a combined oral contraceptive; it is well tolerated and might offer some advantages with respect to other oral contraceptive combinations in its short- and medium-term impact on lipid metabolism.

Rice weed control: current technology and emerging issues in temperate rice

Among temperate rice areas, the United States and Australia are most similar in climate and in the mechanisation of rice culture. Many weed problems, even weed species invading rice, are common to both countries; and the present technology for weed control as well as concern for the impact of these technologies to environmental quality, herbicide resistance, and other weed-related issues bear many similarities. Application of current, and any new, technologies to emerging issues in US rice weed control will therefore be directly relevant to rice production in Australia and all other temperate areas struggling with the same challenges. Weeds are a significant problem in temperate rice culture. In the United States, rice is mechanically direct-seeded, allowing weeds to germinate and establish with the crop. In the last 15 years weed growth and competition has been increased by the adoption of semi-dwarf cultivars, high N fertilisation, and, in water-seeded rice, shallow flooding. High rates, and often multiple applications, of herbicides have been necessary to maximise the yield potential of these cultural systems. Advances in cultural practices and herbicide technology have maintained, if not improved, weed control; but nearly 30 years of propanil use in the southern USA resulted in propanil-resistant barnyard grass Echinochloa crus-galli (L.) Beauv., and after 4 years of continuous use, bensulfuron resistance to 4 aquatic weed species was discovered in California. Although herbicides with different mechanisms of action are needed for alternation in resistance management strategies, fewer are likely to be available. Social and environmental concerns have slowed the development and registration of rice herbicides and increased the cost of controlling weeds. Water quality deterioration from ricefield tailwaters, drift to sensitive crops, the cost of renewing registration in aquatic systems, and weed resistance all forecast reduced herbicide use in rice. Neither cultural practices nor herbicides alone can solve weed problems in direct-seeded, mechanised rice culture. With fewer herbicides and a cultural system highly vulnerable to weed losses, integrated management strategies with better information on which to base weed control decisions will be needed to solve weed problems in temperate rice.

Review article: the management of Zollinger-Ellison syndrome.

Awareness of the sometimes subtle features of Zollinger-Ellison syndrome is important in order not to miss the diagnosis. Immediately after initial diagnostic tests, the patient should be given antisecretory medication, while tests for the type of Zollinger-Ellison syndrome and tumour extent can be delayed. Acid output should be decreased to < 10 mmol/h to control symptoms and prevent complications. Histamine H2-antagonists remain the best available intravenous therapy but omeprazole is the most effective long-term oral therapy and has proved to be safe in nearly 10 years of continuous use. The management of the gastrinoma has changed in recent years since the discovery that the majority of gastrinomas arise outside the pancreas. Exploratory surgery with tumour resection is the treatment of choice in sporadic Zollinger-Ellison syndrome but there are few indications for surgery in patients with Zollinger-Ellison syndrome and multiple endocrine neoplasia type-1. None of the available therapies for metastatic gastrinoma is very effective.

Long-term use of depot-norethisterone enanthate: Effect on blood coagulation factors and menstrual bleeding patterns

Fifty-six women using depot-norethisterone enanthate injections for contraception for 2 years or more were compared with a control group of 48 women not using hormonal contraception. No significant difference was found between the study group and controls for Factors VIIc and Antithrombin III. Factor Xc was reduced in women who had used the injections for over two but less than five years [controls: mean 90.3% SD31.2 vs users for 2–5 yr: 78.7% SD17.1, 95%CI difference in means −0.3,−22.9]. In the group using Net-En for five years or more,Factor Xc was significantly higher than in the control group, but only by 14% of the mean control value [users for over 5 yr: 103.2% SD15.2, 95%CI difference in means 3.1,22.7]. Haemoglobin levels, red cell count and packed cell volume were higher in those using the injections than in the control group. Changes in the platelet count were not statistically significant. Twenty-three women using the injection agreed to keep menstrual diaries. Of these, 20 experienced amenorrhoea for more than two consecutive injection intervals (112 days). It is concluded that long-term use of norethisterone enanthate is not associated with any markedly deleterious effects on Factor VIIc, Xc, or antithrombin III or haemoglobin levels. Amenorrhoea of 4 months or more can be expected after two years of continuous use.

Sorbent removal of air pollutants from museum display cases

Experiments have been carried out under controlled laboratory conditions to investigate the feasibility of removing air pollutants from museum display cases using sorbents. Tests were carried out in the active and passive modes at ambient T and 55 ± 5% RH, with pollutant concentrations of 60–300 (ozone), 75–200 (NO 2), 120–180 (SO 2), 160–1200 (HCHO) and 60–260 nL/L (H 2S) in purified air. In the active mode, many sorbents met or exceeded our target performance, i.e., these sorbents were capable of removing an amount of pollutant equivalent to 20 nL/L of pollutant for one year of continuous use by passing air at 0.1 L/min through 200 g of sorbent. Suitable sorbents included activated carbon, Chromosorb 102, and most of the chemicals the authors selected for this study. Sorbents commonly used in museums and that failed to remove one or more air pollutants under the conditions of our study included silica gel, Purafil, and molecular sieves 13X. Activated carbon met our target performance for all five pollutants tested. In the passive mode, pollutant removal by sorbents and by loss to the display case walls obeyed first order kinetics. The corresponding passive removal rate constants and pollutant half-lives were determined. Removal rate constants ranged from 0.5 to 3×10 −2 in −1, and for carbon were in the following sequence: O 3>SO 2>H 2>NO 2>HCHO. Pollutant removal rates increased with increasing sorbent area. Among mitigation measures aimed at minimizing museum collections damage from air pollutants, none appears to be more cost-effective or easier to implement than the use of sorbents. Specific applications are briefly discussed.

Enhanced Degradation of Fonofos in Soil from Two Southwest Kansas Fields

I studied degradation properties of soil from two southwest Kansas fields in which poor control of western corn rootworm, Diabrotica vergifera vergifera Leconte, occurred after several years of continuous use of fonofos. Bioassays with the red flour beetle, Tribolium castaneum (Herbst), and residue analysis of sterilized and nonsterilized soil from both locations treated with fonofos suggest that enhanced degradation was responsible for rapid breakdown of the toxicant. Implications of this finding for growers and extension personnel concerned with corn rootworm control are discussed.

Microdose intravaginal levonorgestrel contraception: A multicentre clinical trial: IV. Bleeding patterns

A multicentred clinical trial was conducted in 12 countries to assess the contraceptive efficacy and side effects of a low-dose levonorgestrel-releasing vaginal ring. Contraceptive efficacy and side effects, expulsions and removals, and the relation between pregnancy rate and admission body weight of the women have been reported previously. The effect of ring use on vaginal bleeding patterns as observed from daily menstrual diaries kept by the women is the object of this paper.A total of 1005 women were fitted with the ring and 702 of them provided a menstrual diary suitable for analysis. The description of the bleeding patterns is made using a 90-day reference period approach and following the guidelines published by WHO. In addition the longest bleeding/spotting episode and longest bleeding/spotting-free interval are calculated over the entire diary length.Half of the ring users have vaginal bleeding patterns similar to normal untreated patterns. A quarter experience irregular bleeding, 10% have prolonged cycles and 10% have shortened cycles. Over one year of continuous use, there appears to be no significant trend in these patterns. Users with the worst bleeding patterns tend to discontinue first during the clinical trial and are influenced by their more recent experience of vaginal bleeding irregularities. Life-table analysis of discontinuation rates gives an underestimation of the true incidence of bleeding irregularities. Some comments are made on the limitations of the methods of analysis of menstrual diaries.

Anthelmintic resistance in the field: changes in resistance status of parasitic populations in response to anthelmintic treatment.

Changes in anthelmintic resistance in nematode parasites were monitored in sheep grazing on 2 separate farms, but with the same anthelmintic treatment program, over 16 years. High levels of benzimidazole resistance emerged in Ostertagia and Trichostrongylus spp populations on both farms following 9 years of continuous use of this class of drug. Subsequently, variations in the levels of resistance occurred for the same species between farms and between species on the same farm. A change to levamisole for 2 years resulted in a significant reversion towards benzimidazole susceptibility, but a concomitant rise in levamisole resistance, in Ostertagia on one farm. However, benzimidazole resistance increased rapidly following the re-introduction of oxfendazole into the anthelmintic treatment program. Results from both farms illustrate the pitfalls of using one anthelmintic class for an extended period and provide indirect support for the alternation of anthelmintic classes at approximately yearly intervals.

Evolution of coccidial infection in commercial and domestic rabbits between 1982 and 1986

Caecal samples were collected from 751 domestic rabbits of various origin and from 1229 diarrhoeic rabbits issued from 61 commercial rabbitries. They were screened for coccidiosis. In 1982, the year of introduction of the anticoccidal robenidine in commercial rabbits feeds, a dramatic decrease of coccidal infection ratio was detected in commercial rabbitries: only 6% of samples contained > 100 oocysts per gram against 85% in 1979, when sulphaquinoxaline/pyrimethamine was used. Only Eimeria magna, E. media and E. perforans were detected, whereas the highly pathogenic species E. flavescens and E. intestinals had dissappeared from commercial units. After 4 years of continuous use of robenidine, infection ratio rose progressively, although still far below the 1979 levels. Most of the other species reappeared, but only in very low proportions (1–4% of samples). The percentage occurence of E. magna, E. media and E. perforans on the contrary rose progressively to 25, 26 and 34%, respectively, suggesting drug resistance. In domestic rabbitries, the incidence of coccidial infection was markedly higher and all nine species of Eimeria were detected. Eimeria magna, E. media and E. perforans were very common, E. flavescens, E. intestinalis, E. piriformis and E. stiedai were less common, whereas E. irresidua and E. coecicola were relatively rare. Notwithstanding the lower activity of robenidine against E. stiedai, no rise of hepatic coccidiosis became evident.

Accelerated Biodegradation of Herbicides: Proceedings of a Symposium of the Weed Science Society of America February 6, 1986, Houston, Texas

Since the late 1970s, the reason(s) for the performance of certain pesticides to fail after several years of continuous use has been studied. These pesticides include representatives from the herbicide, insecticide, and fungicide groups, encompassing several classes of chemistry–carbamates, carbamothioates (thiocarbamates), and organophosphates.

Effect of Trifluralin Soil Metabolites on Soybean (Glycine max) Growth and Yield

The effects of twelve soil metabolites of trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine] on soybean [Glycine max(L.) Merr.] growth, yield, and seed oil and protein content were determined. The metabolites included oxidative dealkylated, reduced nitro group, benzimidazole, azoxy, azo, oxidized, and hydroxylated derivatives of trifluralin. When applied at 0.22 kg ai/ha and incorporated 7.5 cm deep, no individual metabolite had a significant adverse effect on growth or yield. Three of the metabolites significantly decreased seed oil content and two of the metabolites significantly increased seed protein content. These effects are not considered important in that the differences, while statistically significant, are very small. Also, the amounts of metabolites applied greatly exceeded those expected to be found after many years of continuous use of trifluralin. Potential accumulation of individual metabolites from long-term use of trifluralin does not appear to adversely affect soybean growth, yield, or quality.