Search

Background: The alginate-antacid Gaviscon Double Action (Gaviscon DA) has a combined acid-neutralizing and reflux-suppressing action. Response to treatment in a symptomatic gastro-oesophageal reflux disease (GERD) population has not yet been tested in a large-scale clinical study., Aim: The aim of this study was to assess the efficacy and safety of Gaviscon DA compared with matched placebo tablets in the reduction of upper gastrointestinal symptoms in patients with GERD., Participants and Methods: In this multicentre, randomized, double-blind, placebo-controlled study, adults with GERD symptoms (N=424) received Gaviscon DA or placebo tablets for 7 days. The primary endpoint was a clinically important reduction of at least 1.5 points in the Reflux Disease Questionnaire (RDQ) GERD dimension (combined heartburn/regurgitation) between baseline and the end of the treatment. Secondary endpoints included the change in RDQ score from baseline for individual RDQ dimensions and Overall Treatment Evaluation., Results: A significantly greater proportion of patients treated with Gaviscon DA met the primary endpoint compared with placebo (47.8 vs. 33.2%, respectively, P=0.0031; odds ratio: 1.85, 95% confidence interval: 1.23-2.78). A significant treatment effect was also observed for heartburn, regurgitation and dyspepsia individually. Patients in the Gaviscon DA group rated their overall treatment response greater than patients in the placebo group [mean Overall Treatment Evaluation (SD): 3.2 (3.08) vs. 2.2 (3.34); P<0.001]. No notable differences in the incidence of adverse events were observed between treatments., Conclusion: The alginate-antacid combination, Gaviscon DA, is an effective and well-tolerated treatment to reduce reflux symptoms and associated dyspepsia in symptomatic GERD patients.

Background: Symptomatic breakthrough in proton pump inhibitor (PPI)-treated gastro-oesophageal reflux disease (GERD) patients is a common problem with a range of underlying causes. The nonsystemic, raft-forming action of alginates may help resolve symptoms., Aim: To assess alginate-antacid (Gaviscon Double Action, RB, Slough, UK) as add-on therapy to once-daily PPI for suppression of breakthrough reflux symptoms., Methods: In two randomised, double-blind studies (exploratory, n=52; confirmatory, n=262), patients taking standard-dose PPI who had breakthrough symptoms, assessed by Heartburn Reflux Dyspepsia Questionnaire (HRDQ), were randomised to add-on Gaviscon or placebo (20 mL after meals and bedtime). The exploratory study endpoint was change in HRDQ score during treatment vs run-in. The confirmatory study endpoint was "response" defined as ≥3 days reduction in the number of "bad" days (HRDQ [heartburn/regurgitation] >0.70) during treatment vs run-in., Results: In the exploratory study, significantly greater reductions in HRDQ scores (heartburn/regurgitation) were observed in the Gaviscon vs placebo (least squares mean difference [95% CI] -2.10 [-3.71 to -0.48]; P=.012). Post hoc "responder" analysis of the exploratory study also revealed significantly more Gaviscon patients (75%) achieved ≥3 days reduction in "bad" days vs placebo patients (36%), P=.005. In the confirmatory study, symptomatic improvement was observed with add-on Gaviscon (51%) but there was no significant difference in response vs placebo (48%) (OR (95% CI) 1.15 (0.69-1.91), P=.5939)., Conclusions: Adding Gaviscon to PPI reduced breakthrough GERD symptoms but a nearly equal response was observed for placebo. Response to intervention may vary according to whether symptoms are functional in origin., (© 2017 John Wiley & Sons Ltd.)

Conclusion of the Opinion: The SCCS has concluded that the evidence, both provided in the submission and that available in scientific literature, is inadequate and insufficient to allow drawing any firm conclusion either for or against the safety of any of the individual SAS material, or any of the SAS categories that are intended for use in cosmetic products. As the SCCS has not been able to conclude on the safety of the synthetic amorphous silica (SAS) materials included in the current submission, the Applicant is advised to follow the SCCS Guidance on Risk Assessment of Nanomaterials (SCCS/1484/12). A brief summary is provided to enable/facilitate future evaluation of the SAS materials in cosmetic products., (Copyright © 2015. Published by Elsevier Inc.)

Background: There is a paucity of large-scale studies evaluating the clinical benefit of the Gaviscon Double Action (DA) alginate-antacid formulation for treating gastroesophageal reflux disease (GERD) symptoms., Aim: Randomised double-blind placebo-controlled parallel-group study to evaluate efficacy and safety of Gaviscon DA in reducing heartburn, regurgitation and dyspepsia symptoms in individuals with mild-to-moderate GERD in China., Methods: Participants with symptomatic GERD (n = 1107) were randomised to receive Gaviscon DA or placebo (two tablets four times daily) for seven consecutive days. The primary endpoint compared the change in Reflux Disease Questionnaire (RDQ) score for the GERD (heartburn + regurgitation) dimension between Gaviscon DA and placebo. Secondary endpoints compared the change in RDQ scores for individual heartburn, regurgitation and dyspepsia dimensions, overall treatment evaluation (OTE) scores and incidence of adverse events (AEs)., Results: Mean RDQ GERD scores: 2.51 for Gaviscon DA and 2.50 for placebo at baseline; 1.25 for Gaviscon DA and 1.46 for placebo post treatment. Gaviscon DA was statistically superior to placebo in reducing GERD and dyspepsia RDQ scores [least-squares mean (LSM) difference: GERD -0.21, P < 0.0001; dyspepsia -0.18, P = 0.0004], despite a substantial placebo response. The Gaviscon DA group reported more favourable overall treatment responses than the placebo group across all OTE categories (P < 0.0001). Superior relief of GERD symptoms was observed both in those with non-erosive and those with erosive reflux disease (LSM difference -0.14 [P = 0.038] and -0.29 [P < 0.0001] respectively). Incidence of AEs was similar in both groups., Conclusion: Gaviscon DA tablets provide effective and safe reduction in acid reflux and dyspepsia symptoms in Chinese individuals with mild-to-moderate GERD. ClinicalTrials.gov: NCT01869491., (© 2015 The Authors. Alimentary Pharmacology & Therapeutics Published by John Wiley & Sons Ltd.)

The scaffolds for bone tissue engineering should be porous to harbor the growth of new tissue ingrowths, biodegradable with no toxic end products, and biocompatible with no cytotoxicity. In this study we report that Diopside (CaMgSi2O6) (Dp) particles can be synthesized at a more economical route using the agricultural waste rice straw. Along with chitosan (CS) matrix, the CS/Dp scaffolds were synthesized and evaluated for their physico-chemical properties by SEM, EDS, XRD, FT-IR studies. Addition of Dp particles to chitosan matrix decreased water retention capacity but there was no change in their degradation properties. Dp particles in CS/Dp scaffolds exhibited good affinity for protein adsorption. Apatite forming ability of the CS/Dp scaffolds depicted their bioactivity. These scaffolds were found to be compatible with human osteoblastic cells (MG-63) and the cells were able to attach and proliferate with extended morphology on the CS/Dp membranes. The CS/Dp scaffolds supported up regulation of mRNA expression of osteoblast differentiation marker genes such alkaline phosphatase (ALP), type I collagen (COL-I) in the presence of osteogenic environment suggesting their osteo-conductive nature. In vivo rat model system identified that the CS/Dp scaffolds are biocompatible and may have the property of recruiting cells due to deposition of collagen. Hence, these studies suggest that the prepared CS/Dp scaffolds have potential applications towards bone tissue engineering.

Background: The alginate-antacid, Gaviscon Double Action (Gaviscon DA; Reckitt Benckiser, Slough, UK) suppresses reflux after meals by creating a gel-like barrier that caps and displaces the acid pocket distal to the oesophago-gastric junction. The effect of Gaviscon DA on reflux and dyspepsia symptoms has not yet been demonstrated with a modern trial design., Aim: A pilot study to assess the efficacy and safety of Gaviscon DA compared with matched placebo for decreasing upper gastrointestinal symptoms in symptomatic gastro-oesophageal reflux disease (GERD) patients., Methods: A randomised, double-blind, parallel group study was performed in 110 patients with symptoms of GERD. Patients received Gaviscon DA or placebo tablets for 7 consecutive days. The primary endpoint compared the change in overall Reflux Disease Questionnaire (RDQ) symptom score (combined heartburn/regurgitation/dyspepsia). Secondary endpoints assessed individual dimensions, GERD dimension (heartburn and regurgitation) and overall treatment evaluation (OTE)., Results: There was a greater decrease in overall RDQ symptom score in the Gaviscon DA group compared with the placebo group (Least Squares Mean difference -0.55; P = 0.0033), and for each of the dimensions independently. Patients in the Gaviscon DA group evaluated their overall treatment response higher than patients in the placebo group [mean (standard deviation) OTE 4.1 (2.44) vs. 1.9 (3.34); P = 0.0005]. No differences in the incidence of adverse events were observed between treatment groups., Conclusions: Gaviscon DA decreases reflux and dyspeptic symptoms in GERD patients compared with matched placebo and has a favourable benefit-risk balance. Larger scale clinical investigations of medications targeting the acid pocket are warranted. (EudraCT, 2012-002188-84)., (© 2014 John Wiley & Sons Ltd.)

The purpose of this study was to evaluate whether the use of desensitizing dentifrices used 15 days prior to and after in-office tooth bleaching could eliminate or reduce tooth sensitivity. After institutional review board approval and informed consent, 45 subjects were selected and divided into 3 groups according to the dentifrice selected: Colgate Total (CT), Colgate Sensitive Pro-Relief (CS) or Sensodyne ProNamel (SP). The subjects used toothpaste and a toothbrush provided to them for 15 days prior to bleaching. They were then submitted to two in-office bleaching sessions (Whiteness HP Blue Calcium). Their tooth sensitivity was assessed using the Visual Analog Scale (VAS) for a week after each session. Their tooth shade alteration was measured with a Vitapan Classical shade guide to determine if the dentifrices could influence the effectiveness of the bleaching agent. The data were submitted to Wilcoxon, Kruskal-Wallis and Mann-Whitney tests (α = 0.05). The use of desensitizing dentifrices did not affect the bleaching efficacy. In regard to tooth sensitivity, there was a statistically significant difference between the results of the Control Group and Group T2 after the first session (p = 0.048). There was no statistically significant difference in the results for the other groups after the first session. In regard to the second session, there was no statistically significant difference in the results for all the groups. The use of a desensitizing dentifrice containing nitrate potassium reduced tooth sensitivity during the bleaching regimen. Dentifrices containing arginine and calcium carbonate did not reduce tooth sensitivity. Color change was not influenced by the dentifrices used.

Background: Medical management of GERD mainly uses proton pump inhibitors. Alginates also have proven efficacy. The aim of this trial was to compare short-term efficacy of an alginate (Gaviscon®, 4 × 10 mL/day) and omeprazole (20 mg/day) on GERD symptoms in general practice., Methods: A 14-day multicentre randomised double-blind double-dummy non-inferiority trial compared Gaviscon® (4 × 10 mL/day) and omeprazole (20 mg/day) in patients with 2-6 day heartburn episodes weekly without alarm signals. The primary outcome was the mean time to onset of the first 24-h heartburn-free period after initial dosing. Secondary outcomes were the proportion of patients without heartburn by D7, pain relief by D7, and reduction in pain intensity by D7 and D14., Results: 278 patients were recruited; 120 were included in the Gaviscon® group and 121 in the omeprazole group for the per protocol non-inferiority analysis. The mean time to onset of the first 24-h heartburn-free period after initial dosing was 2.0 (± 2.2) days for Gaviscon® and 2.0 (± 2.3) days for omeprazole (p = 0.93); mean intergroup difference was 0.01 ± 1.55 days (95% CI = -0.41 to 0.43): i.e., less than the lower limit of the 95% CI of -0.5 days predetermined to demonstrate non-inferiority. The mean number of heartburn-free days by D7 was significantly greater in the omeprazole group: 3.7 ± 2.3 days vs. 3.1 ± 2.1 (p = 0.02). On D7, overall quality of pain relief was slightly in favour of omeprazole (p = 0.049). There was no significant difference in the reduction in pain intensity between groups by D7 (p = 0.11) or D14 (p = 0.08). Tolerance and safety were good and comparable in both groups., Conclusion: Gaviscon® was non-inferior to omeprazole in achieving a 24-h heartburn-free period in moderate episodic heartburn, and is a relevant effective alternative treatment in moderate GERD in primary care., Trial Registration: ISRCTN62203233.

Background: Mounting evidence supports a physiological role for silicon (Si) as orthosilicic acid (OSA, Si(OH)4) in bone formation. The effect of oral choline-stabilized orthosilicic acid (ch-OSA) on markers of bone turnover and bone mineral density (BMD) was investigated in a double-blind placebo-controlled trial., Methods: Over 12-months, 136 women out of 184 randomized (T-score spine < -1.5) completed the study and received, daily, 1000 mg Ca and 20 microg cholecalciferol (Vit D3) and three different ch-OSA doses (3, 6 and 12 mg Si) or placebo. Bone formation markers in serum and urinary resorption markers were measured at baseline, and after 6 and 12 months. Femoral and lumbar BMD were measured at baseline and after 12 months by DEXA., Results: Overall, there was a trend for ch-OSA to confer some additional benefit to Ca and Vit D3 treatment, especially for markers of bone formation, but only the marker for type I collagen formation (PINP) was significant at 12 months for the 6 and 12 mg Si dose (vs. placebo) without a clear dose response effect. A trend for a dose-corresponding increase was observed in the bone resorption marker, collagen type I C-terminal telopeptide (CTX-I). Lumbar spine BMD did not change significantly. Post-hoc subgroup analysis (baseline T-score femur < -1) however was significant for the 6 mg dose at the femoral neck (T-test). There were no ch-OSA related adverse events observed and biochemical safety parameters remained within the normal range., Conclusion: Combined therapy of ch-OSA and Ca/Vit D3 had a potential beneficial effect on bone collagen compared to Ca/Vit D3 alone which suggests that this treatment is of potential use in osteoporosis. NTR 1029.

In a randomized, double-blind study, patients with chronic plaque-type psoriasis were either treated with 30 ml colloidal silicic acid gel, orally, daily, and topically with the same gel (n = 15), or were treated identically with placebo gel (n = 15) for 3 months. One stable psoriatic lesion on the knee or elbow was treated topically and followed throughout the study. Five patients in the treated group and seven controls had psoriatic arthropathy and 11 treated patients and 12 controls had psoriatic onychopathy. Three treated patients and six controls withdrew because of skin irritation or lack of efficacy. In the treated group there were clear improvements in scaling, induration and erythema after treatment. The nail changes were cured in five of 10 evaluable patients in the treated group and joint pain was reduced by almost half in the four evaluable patients with arthropathy. There were no such improvements in the placebo group.

Bone prosthesis of apatite- and wollastonite-containing glass-ceramic (AW-GC), a new synthesized material, is known to be excellent in bonding directly with adjacent living bone tissue, in having strong mechanical strength and no toxic effects, in experimental studies. In spinal surgery, massive and strong bone grafts are required for reconstruction of the spinal column affected by a tumor, trauma, or a degenerative disease. However, utilization of bone allograft is not yet socially accepted in Japan and also there are other barriers against the supply of allograft bone. In the present study, AW-GC bone prosthesis was used for reconstructive surgery for various spinal diseases and follow-up studies were performed for an average of 14.9 months (range: 2-36 mo). The clinical results were satisfactory. Thirty patients (males: 17 and females: 13) with an age range of 40-75 years (mean: 55.3 years) were reviewed in this study. Preoperative diagnoses for which an AW-GC prosthesis was required were as follows; vertebral prosthesis: 15 with metastatic tumor of the spine, 3 with burst fracture of the thoraco-lumbar spine; vertebral spacer: 6 with degenerative spondylolisthesis, 2 with isthmic spondylolisthesis, 2 with lumbar intervertebral disc herniation, and one with spinal canal stenosis. Patient's satisfaction, roentgenographic evaluation, laboratory data on blood and urine, and toxic effects were examined in these patients. As a result, the patient's satisfaction for the AW-GC bone prosthesis was high, and the initial fixation and long term stability were excellent. For kyphotic deformity and scoliosis, postoperative correction could be maintained in two patients where correction was attempted, and the usefulness of AW-GC prosthesis as a spinal prosthesis was confirmed. Good bone formation around the prosthesis was observed with time. The clear zone (radiolucent line between ceramic and bone) tended to decrease or disappear. There were no systemic or local toxic side-effects considered to be due to the AW-GC bone prosthesis, or no abnormalities in the laboratory data. These findings suggested that the AW-GC bone prosthesis is a new biomaterial with excellent properties which can be successfully substituted for bone graft in reconstructive spinal surgery.

Background: It is generally accepted that functional dyspepsia is caused by heterogeneous pathogenetic factors. From the clinical point of view acid-related symptoms as heartburn, acid regurgitation and epigastric pain (acid-type) can be separated from general dyspeptic symptoms as predominant fullness, nausea/vomiting (dysmotility-type)., Patients and Methods: In the present study, the influence of a four-week-treatment with ranitidine (twice 150/d, n = 346) in comparison with an antacid (40 mmol/d, n = 340) on the severity and course of symptoms in patients suffering from an acid-related functional dyspepsia was investigated., Results: With ranitidine, acid-related as well as general dyspeptic symptoms disappeared in a significantly higher percentage after two and four weeks compared with antacid. Complete disappearance of symptoms was documented with ranitidine after two weeks in 37% and after four weeks in 66% compared with antacid in 13% and 30% respectively (p < 0.005). Patients with severe symptoms, history of ulcer and long-term dyspepsia and slight endoscopic changes in the upper gastrointestinal tract showed a significant faster and more distinct response. Both kinds of treatment were well tolerated., Conclusion: It is concluded that in acid-related functional dyspepsia ranitidine is superior to antacid in relieving symptoms. Therefore, a probative treatment with ranitidine up to four weeks is recommended as a practical therapeutic alternative in this syndrome.

Objective: Malignant pleural mesothelioma in rural Turkey frequently results from environmental exposure to tremolite asbestos or fibrous zeolite (erionite). The aim of this study was to determine the CT features of malignant pleural mesothelioma in patients exposed to asbestos or erionite., Materials and Methods: The CT scans of 84 patients with proved malignant pleural mesothelioma were retrospectively evaluated. Twenty patients (24%) had been exposed to erionite and 64 patients (76%) had been exposed to asbestos. The CT scans were interpreted by seven observers who did not know the clinical or pathologic findings., Results: CT scans showed either unilateral pleural thickening or pleural nodules/masses in all patients. Pleural nodules were present in 25 patients (30%) and pleural masses in 44 patients (52%). Pleural effusion was found in 61 patients (73%), mediastinal pleural involvement in 78 (93%), pleural calcifications in 52 (62%), involvement of the interlobar fissures in 64 (76%), and volume contraction in 61 (73%). Reduced size of the hemithorax was significantly correlated with chest wall involvement. On the basis of CT findings, the preassigned staging was changed in 21 patients (25%), including 44% of the patients with disease that had been classified as stage I. CT findings were not significantly different between the patients exposed to erionite and those exposed to asbestos., Conclusion: The most common CT findings in cases of malignant pleural mesothelioma were unilateral pleural thickening or pleural nodules/masses with or without effusion. CT provided valuable information on the extent of the disease, which was important for staging. Although the CT features are not pathognomonic, they provide valuable clues to the diagnosis in patients who have been exposed to mineral fibers.

To examine how fiber type, fiber concentration, and fiber size correlate with the presence of asbestos-related disease in workers with heavy chrysotile exposure, we used analytic electron microscopy to determine the fiber content of the lungs of 94 long-term chrysotile miners and millers from the region of Thetford Mines, Quebec. Mesothelioma, airway fibrosis, and asbestosis were strongly associated with a high tremolite fiber concentration, whereas pleural plaques and carcinoma of the lung showed no relationship to tremolite burden. Similar patterns were seen for chrysotile concentration, but further analysis suggested that the apparent effect of chrysotile probably was due to the high correlation (r = 0.70) between chrysotile and tremolite concentration rather than to an independent effect of chrysotile. Increased tremolite-chrysotile ratio was marginally associated with the presence of pleural plaques but not with any other disease. Very high correlations (r > 0.90) between the concentrations of fibers longer or shorter than 8 microns prevented assessment of the effects of long compared with short fibers. Pleural plaques were very strongly associated with higher mean tremolite fiber aspect ratios, but no differences in mean fiber size (length, width, aspect ratio, surface area, and mass) were seen for any other disease. Total fiber size measures (total fiber length/g and others) showed differences similar to fiber concentration for mesothelioma, airways fibrosis, and asbestosis, but no one measure was clearly better than another or better than fiber concentration. We conclude that, in this population of heavily exposed chrysotile miners and millers, the presence of airways fibrosis and asbestosis and, probably, mesothelioma reflects high tremolite burden.(ABSTRACT TRUNCATED AT 250 WORDS)

In an open study, women with biologically aged skin and fragile or thin hair, or brittle nails were treated orally with 10 ml colloidal silicic acid (Silicol) once daily for 90 days and applied colloidal silicic acid to the face for 10 min twice daily. Of the 50 subjects treated, three withdrew from treatment after 30 days because of excessive drying of the facial skin due to topical application. In the remaining 47 subjects there was statistically significant improvement in the thickness and turgor of the skin, wrinkles and condition of the hair and nails. The number of mottles also declined, but the change was not statistically significant. Ultrasound measurements did not detect any statistically significant change in the thickness of the epidermis or elasticity of the skin, but there was a significant increase in the thickness of the dermis.

Background: Sepiolite is an absorbent clay that is used as pet litter. It forms thin crystals, which are a transition between chain and layered silicates. Inhalation studies in animals have shown no evidence of pulmonary damage. This paper reports a cross sectional study of the total work force of the largest sepiolite production plant in the world., Methods: Two hundred and eighteen workers (210 men and eight women) were studied. Height, age, and smoking history were recorded. Chest radiographs were read according to the International Labour Office (ILO) classification by two readers. Readings were used to construct a numerical score, which was then used in statistical analyses. Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were divided by the square of the height. Casella size selective personal samplers were used in randomly selected operatives to collect dust eight years before the rest of the study was carried out. These samples were evaluated gravimetrically. Total dust samples were examined by optical and electron microscopes. Results were analysed by bivariate linear regression, chi 2 tests, and analysis of variance., Results: When allowance was made for smoking habit workers exposed to dry dust showed a significantly greater decline in FEV1 with age than workers with little exposure to dry dust. A similar pattern applied to FVC. Radiographic score showed deterioration with age but no clear differences from other variables. High concentrations of dust were found in the bagging department and also in the classifier shed., Conclusions: The major finding was that lung function deteriorated more rapidly in those who had had more exposure to dust, but there was no evidence of any accompanying radiographic change.

We report a case of a 30-year-old female who had a long-term history of trisilicate-containing antacid intake for gastric discomfort. She had experienced repeated attacks of renal colic. Neither intravenous pyelography nor ureteroscopy could define the presence of calculi. The metabolic evaluations were normal. However, X-ray diffraction revealed a silicate stone. We suggest that the attack of renal colic in those patients with long-term history of trisilicate intake should arouse the possibility of silica urolithiasis.

Conservative techniques for improving the appearance of discolored teeth have become popular in the past decade. These include: in-office bleaching with 30% hydrogen peroxide, which is applied on etched enamel with a gauze pad and then exposed to a bleaching light; home bleaching with a mild form of peroxide, such as 10% carbamide peroxide, which is applied on the tooth surface with custom-made mouthguards; and enamel micro-abrasion with 18% hydrochloric acid, which is applied in a pumice slurry. In this study, the in-office bleaching and enamel micro-abrasion techniques were performed on extracted teeth for investigation of their microscopic effects on the surface enamel. Specimens treated only with 37% phosphoric acid showed an enamel loss of 5.7 +/- 1.8 microns. The specimens treated with 37% phosphoric acid followed by 30% hydrogen peroxide showed enamel loss of 5.3 +/- 1.6 microns; this loss was probably not caused by the hydrogen peroxide, but rather by the etching with 37% phosphoric acid which preceded the hydrogen peroxide application. A direct application of 18% hydrochloric acid for 100 s resulted in a loss of 100 +/- 47 microns. The extent of enamel loss was much greater when the 18% hydrochloric acid was applied in a pumice slurry for the same period of time (360 +/- 130 microns), and the effect was time-dependent. Thus, the pumice and rotary prophy cup used in conjunction with the 18% hydrochloric acid contributed markedly to the loss of surface enamel, enhancing the non-selective stain-removing action of the hydrochloric acid. Therefore, the hydrochloric acid-pumice technique must be used clinically with caution.

The advantages of radiation synovectomy, using preparations containing dysprosium-165 (Dy-165), over conventional materials based on yttrium-90 (Y-90) include a more ideal spectrum of decay energies, and a much shorter half-life permitting quicker and more efficient treatment. A new therapeutic agent, Dy-165 hydroxide macroaggregates, has been developed for the treatment of arthritis making use of these advantages. As part of a clinical trial of this material 42 patients were examined for micronucleus frequency in their peripheral blood lymphocytes prior to, and 2 weeks after, radiation synovectomy using Dy-165 hydroxide macroaggregates or Y-90 silicate. In the majority of patients from each treatment group no significant increase in micronucleus frequency was observed. This indicates that in these cases leakage of material from the site of treatment was not resulting in detectable irradiation of circulating cells irrespective of the choice of radiopharmaceutical. The maximum increase in micronucleus frequency observed corresponded to a radiation dose to circulating cells of approximately 0.3 Gray.

The risks of occupational respiratory disease faced by nonmetal miners are the focus of this review. An understanding of the respiratory risks requires an understanding of the minerology of the ground and rock around the materials being mined. Relevant exposures encompass radon gas and deisel fumes, as well as mineral and rock dusts, including free silica. The types of materials mined and their associated health effects are examined, including the silicates (fibrous silicates such as asbestos, asbestiform fibrous minerals such as wollastonite and fuller's earth, and nonfibrous silicates such as talc and kaolin), sedimentary precipitates such as phosphates, potash, gypsum, and salt, as well as hydrocarbon-containing sedimentary rock such as oil shale.

An open multicenter study was performed to assess the efficacy and safety of alginic acid in two different dosages in 76 pediatric patients with gastroesophageal reflux confirmed by pH monitoring. Among the 69 patients in whom endoscopy was carried out before treatment, 18 had erythematous esophagitis and 5 had erosive esophagitis. Irrespective of the dosage used, the frequency of regurgitation and vomiting decreased significantly (p < 0.00001 and p = 0.01, respectively). Clinical and biochemical tolerance were outstanding and no adverse effects were recorded. On the basis of these data, the recommended dosage is 1 to 2 ml/kg/day in divided doses after meals.

Samples of Metsovo-tremolite asbestos, previously found to be the causative agent of endemic pleural calcification and an increased level of malignant pleural mesothelioma in a rural area of north-western Greece (Metsovo area), were tested in various in vitro toxicity test systems. It was found that asbestos fibres of this type were strong inducers of micronuclei and numerical chromosomal abnormalities while they induced low levels of chromosomal aberrations in mammalian cells in culture. Furthermore, this type of asbestos can induce a low level of in vitro transformation of Syrian hamster embryo cells. The fibres had no effect on gap-junctional cell-cell communication (followed by the dye-transfer method) and did not induce any mutations in the Salmonella typhimurium strain TA102 which is known to be sensitive to the action of various oxidative agents. These results support the hypothesis generated from studies on other types of asbestos that such fibres induce tumours by causing chromosomal mutations.

This article reviews the terminology and manufacturing process for synthetic vitreous fibers. The in vitro and in vivo animal experimental data that correlate fiber toxicity with dose, dimensions, and durability are summarized. Occupational exposure data are presented as well as the potential irritant effects of synthetic vitreous fibers. The ongoing human morbidity and mortality studies are summarized along with current occupational exposure standards. The discussion correlates physical properties related to fiber toxicity and the types of synthetic vitreous fibers.

A 66-year-old woman with a long history of hypertension had an electrocardiogram with giant negative U waves in left precordial leads despite hypokalemia. This seems to be the first report of giant negative U waves induced by uncontrolled hypertension with hypokalemia. The occurrence of negative U waves in the presence of profound hypokalemia is an important observation because it masks the electrocardiographic manifestation of hypokalemia.

Light- and scanning electron microscopical studies with energy dispersive x-ray microanalysis were performed on biopsy material obtained from two patients with longstanding occupational exposure to amorphous silica, in whom radiologically interstitial pulmonary fibrosis in vicinity of dust deposits, which could be identified as amorphous and rarely as crystalline silica, was found. The direct topographical relationship between the dust deposits and the tissue reaction indicate that the amorphous silica incorporated in the fibrotic foci is responsible for the development of the fibrosis.

Estimation of exposure-response relations from epidemiological data is complicated by the fact that exposures usually vary in intensity over time. Cumulative exposure indices, which do not separate the effects of intensity and duration, are commonly used to circumvent this problem. In this paper the estimation of relative risk for specific ranges of exposure intensity from such data is considered using existing statistical methods for fitting multivariate relative risk models. This has the advantage that it does not assume that exposure intensity and duration have equivalent effects on risk. It also throws light on the possible existence of a threshold. The procedure was applied to data from a cohort of 406 vermiculite miners to examine the lung cancer risk associated with exposure to fibrous tremolite, which contaminated the vermiculite. The pattern of exposure-response differed substantially from that obtained using a cumulative exposure index to assess risk.

A 66-year-old female visited our university hospital with the chief complaint of right lower abdominal pain in July, 1984. Kidney-ureter-bladder roentgenograms disclosed the right ureter stone and several left renal stones. She passed the right ureter stone composed of calcium oxalate. Thereafter, she passed small stones twice and sand stones twice until September, 1985. The stone analysis revealed two of them as silica. Although most patients with silica stones reported in Japan had a history of long-term medication of magnesium trisilicate, this patient had not taken this drug. Silica stones are rare and fifteen cases including the present case have been reported in Japan.

Endemic PCs and high incidence of malignant mesothelioma from household use of asbestos have been reported in Metsovo in northwestern Greece ("Metsovo lung"). In the present study, we present similar findings in six more areas of Greece. Like Metsovo, all these areas are located within ophiolite belts. Like Metsovo, material similar to "Metsovo whitewash" has been used for various domestic uses. Asbestos fibers (chrysotile, antigorite and tremolite) were found in three of the six areas. Also, in two, MPM has been diagnosed. These findings suggest that "Metsovo lung" occurs in several areas of Greece and has similar etiology and epidemiology.

Evaluation of the pulmonary hazards associated with exposure to fibrous materials tends to be more complicated than assessments required for particulate materials. Fibers are defined by aspect ratios and it is generally considered that physical dimensions play an important role in the pathogenesis of fiber-related lung diseases. Several digestion techniques have been used to recover fibers from exposed lung tissue for clearance studies. Because many of the digestion fluids are corrosive (e.g., bleach, KOH), it is conceivable that the dimensions of recovered fibers are modified during the tissue digestion methods to assess whether the physical dimensions of bulk samples of fibers were altered following simulated digestion processing. Aliquots of crocidolite and chrysotile asbestos, Kevlar aramid, wollastonite, polyacrylonitrile (pan)-based carbon, and glass fibers were incubated with either saline, bleach, or KOH and then filtered. Scanning electron microscopy techniques were utilized to measure the physical dimensions (i.e., lengths and diameters) of at least 160 fibers per treatment group of each fiber type. Our results showed that the lengths and diameters of glass fibers and wollastonite were altered after treatment with KOH. In addition, treatment with bleach produced a small reduction in both asbestos fiber-type diameters, and greater changes in Kevlar and wollastonite diameters and carbon fiber lengths (P less than 0.05). These results indicate that lung digestion methods should be carefully assessed for each fiber type before initiating fiber clearance studies.

A 62-year-old male visited our department complaining of left flank pain and urinary retention on November 6, 1989. Intravenous pyelography showed small stone shadows in bilateral ureters and lower calyx of kidney and the left kidney was not visualized. Endoscopically, calculi were seen in bilateral ureteral orifice. An ureteral catheter could not be passed up from there bilaterally. On November 13, 1989, January 24 and 26, 1990, calculi were passed out spontaneously. Analysis of the stones revealed silica calculus. The patient had a past history of duodenal ulcers. He was administered magnesium silicate and magnesium alminometasilicate as an anti-acid drug for ten years. Sixteen cases of silica calculus in Japan are reviewed.

An in vitro study was performed to evaluate the effect of four variables on the temperature rise produced by the finishing of restorations. The four variables were: restorative material, finishing agent, finishing time, and depth of dentin under the restoration. Class V preparations were cut on extracted premolars and restored with amalgam, composite, or glass ionomer cement. Finishing was done with wet pumice and cup, wet pumice and a brush, a grit rubber polishing point, and an aluminum oxide- coated disc. Finishing time was continuous or intermittent for up to 1 minute. Dentin thickness under the restoration was 0.5 mm to 3.0 mm. Amalgam produced the highest temperature rises at the pulp, while composite and glass ionomer were no different than the untreated (virgin) tooth. Aluminum oxide discs produced the largest temperature rise, wet pumice with a brush the least. Temperature rise increased almost linearly with continuous finishing, while intermittent finishing significantly reduced temperature rise in all cases. Thickness of remaining dentin was only significant for the amalgam restoration, and then only at 1.0 and 0.5 mm.

In a cross-sectional study undertaken in 1981 using a postal questionnaire, the prevalence of irritative symptoms was investigated among 2,654 Danish construction workers working with mineral wool. An evaluation was undertaken in a multivariate logit analysis of the relationship between exposure level (measured by hours of exposure to mineral wool per month) and prevalence of symptoms. The analysis controlled for the confounders of age, smoking habits, and exposure to organic solvents. With greater exposure to mineral wool, there was a statistically significant increase in the frequency of irritative symptoms from the eyes, the skin, and the upper respiratory tract. Among construction workers working with mineral wool 160-180 hours per month, two-thirds had these symptoms once a week or oftener. The occurrence was 2-3 times higher compared with the construction workers not working with mineral wool. The relationship between exposure to mineral wool and skin and mucous membrane symptoms may be explained by the irritative action of the fibers that are given off during insulation work.

Lung tissue from 76 deceased asbestos cement workers (seven with mesothelioma) exposed to chrysotile asbestos and small amounts of amphiboles, has been studied by transmission electron microscopy, together with lung tissue from 96 controls. The exposed workers with mesothelioma had a significantly higher total content of asbestos fibre in the lungs than those without mesothelioma, who in turn, had higher concentrations than the controls (medians 189, 50, and 29 x 10(6) fibres/g (f/g]. Chrysotile was the major type of fibre. The differences were most pronounced for the amphibole fibres (62, 4.7, and 0.15 f/g), especially crocidolite (54, 1.8 and less than 0.001 f/g), but were evident also for tremolite (2.9, less than 0.001, and less than 0.001 f/g) and anthophyllite (1.7, less than 0.001, and less than 0.001 f/g). For amosite, there was no statistically significant difference between lungs from workers with and without mesothelioma; the lungs of workers had, however, higher concentrations than the controls. Strong correlations were found between duration of exposure and content of amphibole fibres in the lungs. Asbestos bodies, counted by light microscopy, were significantly correlated with the amphibole but not with the chrysotile contents. Fibrosis was correlated with the tremolite but not the chrysotile content in lungs from both exposed workers and controls. Overall, similar results were obtained using fibre counts and estimates of mass.

335 general practitioners participated in an observational study of the alginic acid-containing antacid preparation Gaviscon over a period of eight months. In this period, 2927 patients with reflux disease were treated. Some 62.3% of the patients were treated for six to eight days. Both the tablet and suspension forms of the drug were considered to be effective by both physician and patient in more than 94% of the cases. Drug toleration was also considered good in more than 95% of the cases. The taste of Gaviscon was described as good by 54.7% of the patients, and acceptable by 33.5%. Pregnant women with reflux symptoms were observed in a separate group (n = 52).

The bacteriological contamination of pumice slurry in polishing units in a dental clinical area (high risk), a production laboratory (medium risk), and a non-clinical teaching laboratory (low risk), was investigated. Slurry samples taken from all three areas were found to be heavily contaminated with pathogenic organisms. The investigations were repeated following the addition of a disinfectant with both bacteriocidal and virucidal properties to the pumice. Lower bacterial counts were obtained indicating that routine disinfection of pumice slurries is desirable.

Products fabricated of man-made fibres, which are produced or processed in relatively large amounts in Austria, usually contain glass or rock wool. Regulations laid down limits for the exposure at the workplace to glass/rock wool dust. For this purpose, a gravimetric concentration threshold has been established for the assessment period "working year". A measuring procedure matched to the established threshold is employed to measure the concentration of airborne dust at the workplace.

The cancer risk can be reduced by replacing crocidolite and amosite by chrysotile asbestos, by replacing asbestos by man-made mineral fibres that produce less dust, and by nonfibrous materials. MMMF have been found to be carcinogenic in experiments in animals. All respirable mineral fibres that are retained in the lungs are suspected to increase the lung cancer risk, the fibre length and surface properties appearing to be the decisive factors. For most of these fibres, data so far collected in humans are still insufficient to permit definite conclusions to be drawn. There is a certain amount of evidence to suggest that rock/slag wool may be carcinogenic in humans: lung cancer in workers in the production area in the USA was found to be significantly increased (SMR 134%), and in the early phase of European production an SMR of 257% was observed. In the area of glass wool production, exposure to fibre and lung cancer rates were lower, but showed an increasing tendency with increasing time elapsed since the first exposure to respirable fibres. Methodological problems associated with published epidemiological studies are reviewed, and prevention strategies--which need to give consideration to the possibility that the carcinogenicity per fibre could be higher in the case of MMMF than in chrysotile asbestos--are discussed.

In principle, the fibrosing, preneoplastic and neoplastic morphological reactions to natural and man-made mineral fibres are relatively uniform, and are thus non-specific for the various different types of fibre. In order to establish a causal chain between the injurious "fibrous" agent and the morphologically and clinically manifest pathological lesion, close cooperation between epidemiologists, occupational physicians, pneumologists and pathologists is needed. On its own, the morphological contribution towards solving the problem is of only a limited nature. Light-microscopic, electron-microscopic and element-analytical studies, however, used in conjunction with the results obtained in animal experiments, in the individual case with consideration also being given to aspects of medical insurance, can lead to useful information for the clinical situation and for the generation of expertize.