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At least 919 records · Page 51Linked to original sources
PubMed1996

Nasofrontal duct reconstruction with silicone rubber sheeting for inflammatory frontal sinus disease: analysis of 164 cases.

The authors reviewed their experience in reconstructing the nasofrontal duct with thin silicone rubber sheeting in patients who had chronic inflammatory frontal sinus disease. The 164 patients were divided into four groups. The patients in group 1 had the traditional modified Lynch procedure, while those in group 2 had certain technical variations of the modified Lynch operation. The patients in the other two groups had major technical variations: those in group 3 had a primary osteoplastic flap approach and those in group 4 had revisions of failed osteoplastic flap with fat obliteration operations. Surgical indications included mucopyocele (87 patients), chronic frontal sinusitis (71 patients), osteomyelitis (2 patients), acute sinusitis (2 patients), and subacute sinusitis (2 patients). Follow-up averaged 47 months. At their last clinic visit, 157 patients (96%) were asymptomatic. Forty-six revision procedures were performed in 30 patients (18% of initial cases). There were no major complications. Nasofrontal duct reconstruction using thin silicone rubber sheeting is technically straightforward, safe, and effective.

Adolescent↗
PubMed1976

Free autogenous transplants in preformed pseudosheath silicone rubber pockets.

This investigation suggests that free autogenous grafts, when placed in preformed silicone rubber pseudosheath pockets, will survive as well, if not better, than in delayed or immediate surgical pockets. This supports the clinical assumption that silicone rubber implants can be used and exchanged periodically for larger sizes. At a final exchange, free autogenous tissue could be replaced within the pseudosheath pocket.

Animals↗
PubMed2001

Erosion and intrusion of silicone rubber scleral buckle. Presentation and management.

OBJECTIVE: To describe the clinical presentation and management of erosion and intrusion of silicone rubber implants that are used in scleral buckling procedures for the treatment of retinal detachment. METHODS: The authors identified four patients from their practices during the last 20 years (1978-1998) who had erosion or intrusion of silicone rubber scleral buckles that were used to manage retinal detachment. Approximately 4400 scleral buckling procedures were performed during this period. A retrospective review of the medical records of all patients was performed. Factors that influenced management decisions concerning the intruding buckle are emphasized. RESULTS: All four patients had myopia. The interval between placement of the scleral buckle and development of intrusion ranged from 1 to 20 years. The buckles were intrascleral in three cases and episcleral in one. Recurrent detachment and vitreous hemorrhage were indications for surgical intervention in three cases. After the surgical removal of buckling elements, visual acuity stabilized in all patients and the retina remained attached in all cases. CONCLUSIONS: Erosion and intrusion of scleral buckle are rare complications of scleral buckling procedures. The intruding buckle may be left intact unless there is significant threat to the integrity of ocular structures, recurrent detachment, or hemorrhage. Manipulation of the encircling band or buckle does not necessarily alter the visual acuity or the status of the retina.

Adult↗
PubMed1976

Mortality among rubber workers: Relationship to specific jobs.

This study has examined the ten-year mortality in a single-plant population of 6678 male rubber workers, in terms of the association of specific causes of death with a history of having worked in certain categories of jobs within the rubber industry. The work-histories of individual study subjects were analyzed, in detail, for all workers dying of selected causes of death. Comparison was made with the work-histories of a 22% age-stratified random sample of the total population. Age-adjusted exposure ratios (Tables 3 and 4) were calculated for all nine case groups in all 16 work areas, using differing exposure criteria (i.e. duration and calendar period). These ratios provide an approximation of the increased mortality risk associated with particular work areas. The risk ratios (with their associated confidence intervals), in Table 5, provide more rigorous estimates of these instances of increased mortality risk. For each cause of death studied, there were statistically significant associations with several work areas. For the cancers, the strongest associations tended to be with work areas at the front end of the production line (especially compounding and mixing), where the likelihood of contact with dusts, chemical ingredients, and vapors containing the early reaction byproducts, is high. The reclaim operation and the synthetic plant were each associated with several cancers (respiratory and bladder, and stomach and lymphato-hematopoietic cancers, respectively). The lymphatic leukemias were associated with solvent-exposure areas, especially inspection, finishing, and repair. Ischemic heart disease deaths, at ages 40-54, were strongly associated with having worked in extrusion and tread cementing, and in the synthetic plant. Deaths from diabetes mellitus were strongly associated with the janitoring-trucking category, and with jobs in the inspection, finishing and repair area. These observed associations, calculated after controlling for the variables sex and age, were apparently not due to confounding by smoking and race differences between work areas. The role of selective transfer of sick individuals (into, say janitoring or trucking) warrants further investigation. However, this mechanism is unlikely to be involved in the great majority of the observed associations. Another possible source of spurious inferences of increased risk would be correlation, within work-histories, between two job categories, one of which actually involved increased risk, while the other did not. Such associations could occur if certain job sequency trends existed within this working population. (Preliminary analyses indicate that this likelihood is not great; however, further analysis is planned.) Detailed study of specific environmental agents, historically and cross-sectionally, is currently underway, in an attempt to identify the work-environment agents responsible for the associations reported here.

Age Factors↗
PubMed1996

A medical-center-wide, multidisciplinary approach to the problem of natural rubber latex allergy.

Latex is a common cause of occupational allergy in health care workers; latex-sensitized patients are at increased risk of allergic reactions in medical environments. Skin test reagents and latex-specific immunoglobulin E immunoassays were established for diagnosis of latex allergy. Inhibition immunoassays were developed for measuring latex aeroallergens and latex allergens in rubber products. A registry of latex-sensitive employees was established. High-allergen gloves were removed from the medical center inventory; latex aeroallergen levels subsequently declined. Despite an increasing number of gloves used annually, expenditures for gloves in 1994 were lower than in previous years. Latex-sensitive individuals can be identified using skin tests or immunoassays. Latex aeroallergen levels in medical environments can be reduced substantially at lower cost by using powder-free rubber gloves with lower allergen content.

Air Pollutants, Occupational↗
PubMed2000

Natural rubber latex: glove use, sensitization, and airborne and latent dust concentrations at a Denver hospital.

Exposure to natural rubber latex may cause immediate hypersensitivity reactions. Published latex sensitization prevalence rates range from 2.9% to 22% among health care workers, and from 0.12% to about 20% of occupationally unexposed populations. In this study, self-administered questionnaires addressed job and personal characteristics, glove use, and symptoms in two groups of hospital workers: those who regularly used latex gloves and those who did not. Serum was tested for latex-specific immunoglobulin E. Air, surface, and air-filter dust samples for natural rubber latex were collected. The prevalence of latex sensitization was 6.3% in the non-users and 6.1% in the latex glove users (P = 0.9); 81.3% of sensitized workers were atopic compared with 59.5% of non-sensitized workers (P < 0.05). Reporting of work-related hand dermatitis was more common in the latex glove users (23.4%) than in the non-users (4.9%), as were rhino-conjunctivitis (16.3% and 7.9%, respectively, [P < 0.01]), and hand urticaria (9.9% and 2.1%, respectively, [P < 0.01]). There was no significant difference in work-related symptoms between the sensitized and non-sensitized workers. Environmental concentrations of latex were higher in the work areas of the non-sensitized workers, but higher in the clinical than in the non-clinical areas. Occupational latex glove use was not a risk factor for sensitization.

Adult↗
PubMed1997

Adhesion of Pseudomonas aeruginosa to silicone rubber in a parallel plate flow chamber in the absence and presence of nutrient broth.

The physico-chemical cell-surface properties of Pseudomonas aeruginosa AK1 and its adhesion to silicone rubber under flow were compared for cells suspended in phosphate-buffered saline (PBS) or PBS supplemented with 2% nutrient broth. Addition of 2% nutrient broth to cells suspended in PBS yielded minimal growth and did not significantly change the mean zeta potential of the organisms, which was around -13 mV. However, a comparatively larger proportion of the organisms had more negative zeta potentials in the presence of nutrient broth. This change was concurrent with a slight decrease in cell-surface hydrophobicity, as measured by water contact angles, from 119 degrees to around 112 degrees. The initial deposition rate of P. aeruginosa AK1 to silicone rubber, as studied in a parallel plate flow chamber, increased from 344 cm-2 s-1 in the absence of nutrient broth to 505 cm-2 s-1 in its presence. No stationary level of adhesion was observed in the presence of nutrient broth, instead the number of adhering cells increased steadily at a rate of approximately 85 cm-2 s-1. Fluorescent staining of adhering cells demonstrated that for adhesion from buffer only 2% of the adhering cells were metabolically active, whereas in case of deposition from PBS supplemented with nutrient broth, 67% of the adhering cells were metabolically active. It is concluded that the deposition rates measured in the parallel plate flow chamber with 2% nutrient broth added to the PBS suspension represent an interplay of adhesion and surface-associated growth.

Bacterial Adhesion↗
PubMed2001

Low-frequency dielectric relaxation in rubber.

A rubber sample is investigated by dielectric spectroscopy in the frequency range from 10(-2)<or=nu<or=10(7) Hz. Measurements are performed under both isothermal (at ambient pressure) and isobaric conditions. The spectral shape of the loss peaks is symmetric and temperature and pressure independent. Hence the temperature-pressure-frequency superposition principle is fulfilled in a cross-linked rubber sample. The Vogel-Fulcher-Tammann temperature law and its pressure counterpart well describe the respective temperature and pressure dependences of relaxation times. In addition we determined the activation volume from isothermal relaxation data.

Journal Article↗
PubMed2004

Two rubber balloons: phase diagram of air transfer.

Two identical rubber balloons are partially inflated with air (to different extent) and connected by a hose with a valve. It is found that depending on initial balloon volumes, when the valve is opened the air will flow either from the larger (fuller) balloon to the smaller (emptier) balloon, or from the smaller balloon to the larger one. The phenomenon is explained in terms of the nonideal rubber elasticity of balloons. The full phase diagram for the air flow dynamics is constructed.

Journal Article↗
PubMed2002

Memory effect on the glass transition in vulcanized rubber.

The memory effect upon glassification is studied in the glass-to-rubber transition of vulcanized rubber with the strain as a controlling parameter. A phenomenological model is proposed, taking the history of the temperature and the strain into account, by which the experimental results are interpreted. The data and the model demonstrate that the glassy state memorizes the time course of strain upon glassification, not as a single parameter but as the history itself. The data also show that the effect of irreversible deformation in the glassy state is beyond the scope of the present model.

Journal Article↗
PubMed2005

Hyperelasticity, viscoelasticity, and nonlocal elasticity govern dynamic fracture in rubber.

Dynamic cracks in rubber can spontaneously oscillate under certain biaxial strain conditions [R. D. Deegan et al., Phys. Rev. Lett. 88, 014304 (2002)]. We have found that this unusual phenomenon can be understood from the unique mechanical properties of rubber: hyperelasticity, viscoelasticity, and nonlocal elasticity. While all these are important, the decisive role of nonlocality needs to be particularly emphasized. Through numerical simulations with a lattice model, we have quantitatively reproduced the experimental results.

Journal Article↗
PubMed2005

'Black henna' tattoos: an occult source of natural rubber latex allergy?

Temporary 'black henna' tattoos are an increasingly popular body decoration with a growing incidence of associated adverse events. We report the case of a 14 year old girl presenting with an acute allergic contact dermatitis to hair dyes. Some years previously she had a 'black henna' tattoo with prior application of a tacky transfer to the skin to outline the design followed some days later by an acute localised blistering reaction. Patch testing to an extended British Contact Dermatitis Society standard series showed relevant positive reactions to paraphenlyenediamine (PPD) and thiuram mix, as well as to several of the azo disperse dyes. We went on to perform prick testing to natural rubber latex (NRL), showing a positive reaction to the commercial HEP 100 concentration. We propose that through the initial acute reaction caused by PPD in the 'black henna' our patient was not only sensitized to PPD, but also to thiuram and natural rubber latex which may have been present in the tacky transfer applied prior to 'tattooing.' We would add that temporary 'black henna' tattoos may have more important consequences than previously thought on patients' future health by sensitization to NRL.

Adolescent↗
PubMed2005

Extraction of haptens from solid products and their delivery to the skin, exemplified by dithiocarbamates from rubber gloves.

Allergic contact dermatitis is often caused by solid products such as rubber gloves. Patch testing with the product as is often gives negative results. Extraction of the haptens into an organic solvent is commonly performed to achieve a more correct investigation. The technique used for extraction of haptens from solid materials is only sporadically described. In this study, we investigated and optimized the yields of dithiocarbamates obtained by extraction from rubber gloves. The influence of solvent, extraction time and the procedures for extraction are evaluated. The delivery of zinc dibutyldithiocarbamate from the patch test preparation to the skin is determined.

Chromatography, High Pressure Liquid↗
PubMed2005

Allergic contact dermatitis from natural rubber latex in atopic dermatitis and the risk of later Type I allergy.

The aims of the study were to assess whether contact dermatitis in children could be due to a delayed hypersensitivity reaction to natural rubber latex (NRL) and to define risk factors for later occurrence of Type I hypersensitivity to this allergen. Among 1800 children investigated for contact dermatitis, 55 were referred on suspicion of rubber allergy and had patch tests to NRL, as well as prick tests and blood tests for specific immunoglobulin E (IgE). A 2-year follow-up was then carried out. Delayed hypersensitivity to NRL was confirmed in 32 children. Patch testing with NRL proved to be positive, and clinical improvement confirmed the diagnosis and relevance of patch tests. 30 of these 32 patients had associated atopic dermatitis (AD). Prick tests and blood tests for specific IgE to latex were negative at the time of diagnosis. A 2-year follow-up showed that 10 of 27 patients presenting initially with a positive patch test without associated Type I sensitization later developed immediate hypersensitivity. Children with AD are at high risk for allergy to NRL protein. Exclusion of this allergen should be strongly advised in atopics because of the dual risk of dermatitis and later evolution into severe Type I hypersensitivity.

Allergens↗
PubMed2005

Blue rubber bleb naevus syndrome associated with cortical blindness.

An 83-year-old woman was admitted for investigation of sudden loss of vision. Extensive plum-purple papules and nodules involved her skin and lips but not mucosae. A cutaneous biopsy demonstrated irregular vascular cavernous channels in the dermis and subcutis; deeper vessels displayed smooth muscle. Blue rubber bleb naevus syndrome was diagnosed. This patient had no gastrointestinal symptoms, no family history of blue rubber bleb naevus syndrome, and only developed cutaneous signs after 60 years of age. Magnetic resonance imaging of the brain found multiple cerebral and cerebellar cavernomas with two larger foci of haemorrhage in both occipital lobes, with the largest in the right occipital lobe being associated with calcification. These most likely represent bleeding in relation to cavernomas believed to be the cause of decreased vision, predominantly in the left eye.

Aged↗
PubMed2004

Ano-rectal physiological changes after rubber band ligation and closed haemorrhoidectomy.

OBJECTIVE: The effect of treatment for haemorrhoids on ano-rectal physiology was studied in a prospective longitudinal follow-up study. METHODS: Thirty-six consecutive patients having II-III degree (Group I, 18 patients) or IV degree (Group II, 18 patients) haemorrhoids were studied. Group I underwent rubber band ligation while Group II underwent closed scissors haemorrhoidectomy. RESULTS: Patients in Group I had significantly lower maximum basal pressure (P < 0.05) and also significantly lower maximum squeeze pressure (P < 0.05) compared to Group II before treatment. Both basal and squeeze pressures dropped after haemorrhoidectomy (P < 0.001) whereas they remained unchanged after rubber band ligation (P > 0.1). The volume of first sensation was higher in Group II before treatment (P < 0.001) and remained so after treatment. Rectal compliance was higher (P < 0.005) in Group I before treatment. It increased significantly in both groups (P < 0.05, Group I; P < 0.001, Group II) after treatment. CONCLUSIONS: The results show a significant increase in anal pressures in constantly prolapsing (IV degree) haemorrhoids. Most of the physiological differences observed between the two groups were abolished after treatment. This suggests that these may be a consequence rather than a cause of haemorrhoids.

Aged↗
PubMed2006

A prospective study of outcome from rubber band ligation of piles.

OBJECTIVE: With the recent introduction of stapled anopexy it is timely to review the benefits of existing treatment options for piles. This study investigates the effectiveness and safety of rubber band ligation (RBL) of piles in the outpatient setting. PATIENTS AND METHODS: Two hundred and fifty-two consecutive patients referred with piles in an 18-month period were studied prospectively. In those patients deemed suitable for banding of piles, data were collected on symptoms, proctoscopic appearance and degree of piles. Short and long-term outcome data were recorded for success of treatment and complications. RESULTS: Of 203 patients considered suitable and who attended for RBL, 176 kept their follow-up appointment. One hundred and forty-eight (84%) had been rendered symptom-free. A third of patients, however, had proctoscopic evidence of persistent piles, whilst in half of those patients with continuing symptoms the anal cushions appeared normal. Six (3%) patients had suffered a complication. Long-term follow-up by questionnaire found that 44% of respondents remained asymptomatic at a median of 46 months from banding. Six (5%) of 117 responders to the questionnaire had, though previously normal, suffered a postbanding impairment of continence. CONCLUSION: Most patients with piles of any degree can be safely managed by rubber band ligation, but return of symptoms in the long term affects more than half of patients treated.

Adult↗
PubMed1986

Stress in calves castrated surgically or by the application of rubber rings.

The effects of castration were studied in calves 4 to 11 weeks of age, using increases in salivary cortisol as an indicator of stress. Groups were castrated surgically or by rubber ring application or were non-castrated (control) females. The surgically castrated group showed more agitation during the operation, but both castrated groups resumed normal behaviour soon after the operation was completed. The short-term salivary cortisol response was significantly higher after surgical castration than after the application of rubber rings, where, in turn, it was significantly higher than in the control group. Salivary cortisol was elevated over a period from 15 min to 3 h following the castration, but at 4, 24 h and 6 days post-treatment there were no significant differences between treated groups and controls.

Animals↗