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PubMed1994

[The capability of silicone prostheses to promote postoperative infections. An in-vitro study].

The authors have quantitatively evaluated and compared in vitro the Staphylococcus aureus and Staphylococcus epidermidis strain adhesiveness on various types of silicone used in surgery. The results show that there are some adhesiveness differences between the two assayed strains (S. epidermidis adhesiveness > S. aureus adhesiveness) and among silicone types (adhesiveness on soft silicones > adhesiveness on hard silicones). However all silicones are suitable substrata for in vitro bacterial adhesion.

Bacterial Adhesion↗
PubMed1995

[Silicone oil removal in 31 cases].

Silicone oil removal was performed on 32 eyes of 31 cases after silicone oil injection for an average of 13.9 months. The reasons for the silicone oil removal are the complications such as cataract, glaucoma, emulsification of the silicone oil and so on. Complete retinal reattachment without any complications was found in 6 eyes of the 32 cases. Retinal reattachment remained in place in 24 eyes after the removal, and 24 eyes achieved postoperative visual acuities > or = 0.02. After the removal, in 7 of 8 eyes with complication, retinal detachment reoccurred. The significance and the timing of the silicone oil removal were discussed in this paper.

Cataract↗
PubMed1994

PCR in a silicon microstructure.

Devices for performing polymerase chain reactions (PCR) have been developed for use with photolithographed silicon. Microchambers capable of holding between 5.0 and 10 microL of PCR reagents were constructed by etching specific areas of rectangular silicon chips (17 x 15 mm), which were then capped with Pyrex glass. These silicon devices (PCRChips), which were etched to depths of 40-80 microns, permitted free flow of fluids in the microchannels and microchambers. Access to the microchambers was through holes in the silicon. Thermal cycling of the PCR reagents was achieved by placing the disposable PCRChip in a small holder containing a computer-controlled Peltier heater-cooler. Successful amplification was demonstrated by electrophoresis of products in agarose gel containing ethidium bromide, and the migration of the product was compared with that obtained in a commercially available thermal cycler. The thermal characteristics of the silicon, coupled with the high surface area to volume ratio in the new devices, are particularly advantageous features for amplification by PCR.

Bacteriophage lambda↗
PubMed1994

[Determination of contrast sensitivity in patients with silicone oil tamponade].

UNLABELLED: The issue of whether silicone oil has a toxic effect on the retina is still being debated. In order to verify possible retinotoxic effects, the authors studied the variations of retinal function by means of computerized perimetry on patients who had undergone a vitreoretinal operation with injection of silicone oil in the vitreous cavity. Silicone oil remained in the eyes for a period of 120 days +/- 15. PATIENTS AND METHODS: 14 patients under treatment for vitreoretinal pathologies sparing the macula underwent five examinations (Macular Threshold Test of the Humphrey Field analyzer): two examination during the period silicone oil was in the vitreous cavity (30 days after injection and 10 days before removal) and three examinations after its removal (at 30, 90, and 180 days). RESULTS: When the paired t-test and ANOVA test were applied to our results, there were no significant differences in the light-difference sensitivity. CONCLUSIONS: These data do not indicate that silicone oil a retinotoxic effect (revealed by means of computerized perimetry) when it is removed within 4 months.

Adult↗
PubMed1993

Silicone mammary implants and connective tissue disease.

The American Food and Drug Administration recently restricted the use of silicone gel-filled mammary implants for breast augmentations and reconstructions because a number of case reports had suggested that there was an association between silicone and connective tissue disease. We have found 36 such case reports published since 1982. Systemic sclerosis is the most common reported diagnosis (n = 15). Implants were removed from 15 patients, in nine of whom symptoms improved. The mechanism behind the postulated relationship is obscure, and most authors focused on an auto-immune-like response to silicone, which acts directly as a hapten or as an adjuvant. We found no conclusive evidence to implicate silicone mammary implants in connective tissue diseases. We do, however, recommend removal of implants from patients with severe connective tissue diseases. Patients with symptoms or active connective tissue disease should not be considered for silicone implants.

Adult↗
PubMed1993

[The use of domestic silicone oil in the treatment of complicated retinal detachment].

Vitrectomy and domestic silicone oil were used in the treatment of 42 eyes with complicated retinal detachment, and the retina was reattached in 34 cases or a rate of 80%, which dropped to 54% in 4-24 months postoperative. Among 7 eyes with successful retinal attachment and silicone oil removal, 1 eye developed recurrent retinal detachment. The therapeutic effect of silicone oil and operative complications were discussed. Removal of intravitreal silicone oil 3-6 months after injection was necessary to avoid adverse consequences. The study indicated that pars plana vitrectomy with silicone oil injection was an effective procedure in the management of complicated retinal detachment.

Eye Diseases↗
PubMed1993

[Observations on vitrectomy with silicone oil injection].

Silicone oils were injected in 37 eyes of 37 patients among 95 patients performed vitrectomy during 1988-1990. The indication was complicated retinal detachment except for 2 cases of diabetic proliferative retinopathy and vitreous hemorrhage. In 29 (78.4%) of the 37 eyes, the retina was totally reattached, and in 7 eyes partially reattached that did not regain ambulatory vision. In 22.7% of the eyes successfully operated, cataracts developed with silicone oil 1,000mPa.s while transient hypertension occurred in 27.3% with silicone oil 5,000mPa.s. Vitrectomy with silicone oil filling may help some retinal detachments that are refractory to conventional retinal and vitreous operations; however, due to possible complications, the use of silicone oil should be in limited cases and removed after retinal reattachment.

Adult↗
PubMed1993

Silicone replica technique and automatic confocal topometry for determination of corneal surface roughness.

No method for the objective measurement of corneal surface roughness has thus far been available for experimental and clinical investigations. The surface roughness of photoablated porcine corneas was investigated with the silicone-cast method and automatic confocal topometry. Photoablation was performed with the 193-nm excimer laser. Surface roughness was determined as a function of the repetition rate (2-60 Hz; fluence, 180 mJ/cm2; beam diameter, 2 mm; 300 laser pulses/experiment). Immediately after photoablation, a silicone replica of the ablated surface was made and analyzed later using confocal topometry. The surface roughness for excimer laser ablation was found to be frequency-dependent: 0.4-0.6 +/- 0.08 micron (2-30 Hz) and 1.2 +/- 0.12 micron (60 Hz). The silicone cast of the cornea of a healthy eye gave an exact image of the profile and curvature: the difference between radius measurements of the cornea (Zeiss ophthalmometer) and of the silicone cast (laser topometer) was about 0.5%. As the silicone-cast method can also be used for in vivo animal experiments, the correlation between surface roughness and laser repetition rate can be studied with regard to photorefractive keratectomy.

Animals↗
PubMedDate not supplied

Determination of traces of silicone defoamer in fruit juices by solvent extraction/atomic absorption spectroscopy.

Silicone defoamers are used to control foam during the processing of fruit juices. Residual silicones in fruit juices can be separated from the naturally occurring siliceous materials in fruit products and selectively recovered by solvent extraction, after suitable pretreatment. The recovered silicone is measured by atomic absorption spectroscopy. Silicone concentrations as low as about 1 ppm can be measured. The juices are accurately spiked for recovery studies by the addition of silicone dispersed in D-sorbitol.

Antifoaming Agents↗
PubMed1993

[Silicone breast implants and connective tissue disease].

The American Food and Drug Administration (FDA) recently introduced a temporary stop for silicone breast prosthesis implants. The reason is a suspected connection between silicone implants and the development of autoimmune disease. The present authors have reviewed the 32 cases of connective tissue disease which have hitherto been reported in the literature, of these 13 were cases of systemic sclerodermia. On the basis of approximately 2 million silicone prosthesis implants which were introduced in USA alone during the past 20 years, approximately 200 cases of systemic sclerodermia would be anticipated. Nevertheless, the fact that several patients had spontaneous remission of their chronic disease after removal of the silicone implant speaks in favour of a possible connection. It is concluded that on account of the limited number of cases of connective tissue disease which have been reported in patients with silicone implants, insufficient evidence is present to stop implantation of these. Implantation of prostheses filled with saline are recommended for patients with connective tissue disease.

Adult↗
PubMed1995

Randomised comparison of silicone versus Teflon cannulas for peripheral intravenous nutrition.

The use of peripheral intravenous nutrition using standard Teflon cannulas is limited by a high incidence of thrombophlebitis, with resultant frequent line changes and compromised nutritional therapy. Fine-bore silicone catheters may reduce the incidence of thrombophlebitis; we prospectively compared the silicone catheter with a Teflon cannula in a randomised trial. Seventy-nine surgical patients were randomised to receive peripheral nutrition (10 g nitrogen; 1770 kcal; 650 mOsm/l) either via a Teflon cannula (18G, 4.4 cm long) or via a silicone catheter (23G, 15 cm long). Compared with the group randomised to a standard Teflon cannula, patients fed via a silicone catheter had a significant (P < 0.001) improvement in (a) median time to survival of the first catheter (125 h vs 48 h); (b) incidence of catheter reinsertions (13% vs 75%); and (c) incidence of thrombophlebitis (10% vs 48%). Delivery of a moderately hypertonic nutritional solution through a fine-bore silicone catheter is safe, durable and well tolerated, with a low incidence of complications relative to a Teflon cannula. An expanded role for this catheter in nutritional therapy is feasible, which may reduce the requirement for central venous parenteral nutrition.

Adult↗
PubMedDate not supplied

Impact of silicone implants on the lives of women with breast cancer.

PURPOSE/OBJECTIVES: To describe the impact of silicone implants on the lives of women with breast cancer. DESIGN: Qualitative analysis of telephone interview data. SAMPLE: 120 women from across the United States who have reported to the Food and Drug Administration problems with breast implants following mastectomies. METHODS: Telephone interviews were used to gather responses to 110 questions. Qualitative analysis of narrative data was linked with quantitative data. MAIN RESEARCH VARIABLES: Concerns and feelings about breast implants; potential problems with silicone implants; source of information about problems; how they coped with the silicone implant controversy; problems related to their breast implants; the effect of health problems on day-to-day activities, relationships with significant others, work, and any other important aspects of their lives; and advice they would give other women regarding breast implant surgery. By linking the qualitative analysis of narrative data with quantitative data, the investigators sought to answer the following research question: Do the patterns of responses differ based on specific systemic physical problems, reported localized breast problems, or implant problems? FINDINGS: The women reported poorer quality of life and feelings of worry and anger because of health problems. They perceived they had received incomplete information and often had complaints dismissed by their healthcare providers. Most of them would not recommend silicone implants for patients undergoing mastectomy. The women's levels of satisfaction were directly associated with their feelings of being informed and the type of health problems they experienced. CONCLUSIONS: Women need reconstruction options following mastectomy, however, use of silicone implants can result in additional health problems and decreased quality of life as a result of those problems. IMPLICATIONS FOR NURSING PRACTICE: Nurses can assume the role of breast health educator, which includes counseling women with breast cancer about breast implants and other reconstructive options. Study results will help health providers care both for those patients considering treatment options and those coping with the problems and concerns related to their breast implants. Women should be told the inherent risks and complications associated with breast implants and also told when "we don't know."

Adult↗
PubMed1996

Management of retinal redetachment following silicone-oil removal.

The aim of the present investigation was to study the clinical course of eyes presenting with retinal redetachment after silicone-oil removal (SOR), with special regard being paid to the long-term visual outcome. Between October 1989 and September 1994, SOR was performed on a consecutive series of 262 eyes that had previously undergone vitrectomy combined with silicone-oil injection for complex retinal detachments. The records of these patients were analyzed retrospectively. The mean follow-up period after redetachment following SOR was 26.3 (range 6-45) months. Redetachment occurred in 35 eyes (13.4%), mostly within 1-3 months of SOR. Redetachment was not dependent on the surgical procedure or the underlying disease. A total of 24 eyes were revitrectomized and a stable flat retina was the result in 23 eyes (65.7%). At the latest follow-up visit, 18 eyes (51.4%) had a visual acuity (VA) of > or = 0.02 and 14 eyes (40%) had a VA of > or = 0.1. In 12 eyes (34.3%) the final VA equalled the best VA recorded before redetachment; an increase in VA occurred in 6 eyes (17.1%) and a deterioration was noted in 17 eyes (48.6%). Only 6 of the 17 eyes that deteriorated had displayed a VA of > or = 0.02 prior to SOR and lost formed vision due to redetachment; these 6 eyes represent 17.1% of the eyes presenting with redetachment after SOR and 2.3% of all 262 eyes that had undergone SOR. These observations demonstrate that revitrectomy is an effective treatment for retinal redetachment after silicone-oil removal. The final failure rate does not appear high enough to justify a contraindication for routine removal of silicone oil, especially since it remains a matter of speculation as to whether these eyes would have fared better had removal of silicone oil been avoided.

Adolescent↗
PubMed1995

[Toxic substances with silicone oil after intraocular injections].

In articles about the analysis of intraocular silicone oil, mostly the amount and toxicity of low-molecular-weight components (LMWC) have been investigated. This study was intended to analyze the components of silicone oil following a longer intraocular application. We analyzed silicone oil removed from human eyes with PVR a few months postoperatively. The fraction of LMWC was further investigated and we separated 16 different components belonging to hexachlorhexanes (HCH), polybiphenyls (PCB) and dichlor-diphenyl-trichlorethane (DDT). All these substances are said to have a toxic and cancerogenic effect as well as weakening the immune system. The concentration of these organic chloride components measured in intraocular injected silicone oil is about the same as fatty tissue but exceeds the concentration in human blood enormously. Possible damage to the retina by these toxic substances is another reason for early removal of silicone oil if the situation of the retina is stable.

Adolescent↗
PubMed1995

[Cataract after silicone oil tamponade and its surgical treatment].

Twelve eyes of twelve cases of cataract after complicated retinal detachment surgery and silicone oil tamponade were treated in this report. Successful extracapsular cataract extraction (ECCE) was performed on 10 of the 12 cases, no oil escape occurred in any of the operation and in one eye an intraocular lens was implanted. Intraoperatively, loss of large amount of silicone oil occurred and it was removed completely in ECCE in 2 cases. After the follow-up periods of 3 approximately 30 months (mean, ten months), ten cases with the intact posterior capsule and silicone oil in place had a good view of the fundus, their retinae were attached and visual acuities were recovered above the best levels after retinal detachment surgery. Two cases with silicone oil removal suffered from retinal re-detachment. The main points of the surgery were discussed, and the effective method of prevention from silicone oil escape and maintenance of the transparency of the posterior capsule after ECCE were proposed.

Adolescent↗
PubMed1996

Increased urinary NO3(-) + NO2- and neopterin excretion in children breast fed by mothers with silicone breast implants: evidence for macrophage activation.

OBJECTIVE: To determine whether children breast fed by mothers with silicone implants (BFSI) have increased urinary excretion of nitric oxide (NO) metabolites and neopterin, whether these are associated with esophageal dysmotility, and whether in vitro incubation of macrophages with silicone increases NO synthesis. METHODS: In a case-control study based on laboratory investigation, 38 BFSI children (17 male, 21 female, mean age 7.1 +/- 3.6 years, range 0.5-16.5) were compared with 30 controls (14 male, 16 female, mean age 8.4 +/- 3.5 years, range 2.5-17). Urinary NO was quantitated using the Griess reaction. Urinary neopterin was determined by radioimmunoassay. Murine macrophages were cultured with or without silicone and NO production assayed. RESULTS: Urinary NO and neopterin were significantly increased in BFSI children compared with controls. There was a significant inverse relationship between urinary neopterin excretion and the severity of esophageal dysfunction. In vitro nitrite production was nearly 60% higher in macrophages grown on silicone compared to other growth conditions. CONCLUSION: BFSI children have evidence of macrophage activation and this is associated with esophageal dysmotility. In vitro data support the proposal that silicone exposure causes macrophage activation.

Adolescent↗
PubMed1996

Vacuum delivery at The Maternity Hospital Kuala Lumpur: a comparison of metal and silicone cups.

OBJECTIVE: To compare the advantages and disadvantages of the New Bird metal cups and silicone cups in terms of maternal and foetal outcome. To study the adverse effects and factors associated with failed vacuum deliveries. DESIGN: A prospective randomised study of all vacuum deliveries from 1 December 1991 to 31 April 1992. The Hanshin electrical vacuum pump was used. SETTING: A large obstetric unit-The Maternity Hospital Kuala Lumpur (MHKL). SUBJECTS: Seventy-two consecutive patients where vacuum deliveries were indicated. Forty had metal and 32 had silicone cups. Another 7 vacuum deliveries using the manual vacuum pump were excluded. MAIN OUTCOME MEASURES: Success rate of vaginal delivery, birth canal injuries, post-partum haemorrhage, duration of hospital stay, Apgar score, foetal injuries (scalp-ecchymosis, haematomas) neonatal jaundice, the rate of special care nursery (SCN) admission and neonatal mortality rate. RESULTS: Failure to deliver with silicone cups alone was 21.9% compared to 10% for metal cups alone. Material morbidities and serious foetal scalp injuries were almost the same in both cups. However, minor foetal scalp injuries were significantly lower with silicone cups. Maternal height and baby's weight had no independent predictive values for successful vacuum delivery. When the foetal head was palpable per abdomen, the failure rate was 54.5% compared to 8.2% when it was not. Failed vacuum deliveries were associated with increased maternal and foetal morbidities. CONCLUSION: Silicone cups and metal cups can be equally dangerous to the baby. Although our sample size was small, we recommend that vacuum delivery be avoided if the foetal head is palpable per abdomen.

Contraindications↗
PubMed1996

Magnetic resonance imaging in the evaluation of eyes treated with silicone oil.

BACKGROUND AND OBJECTIVE: To evaluate the sensitivity of magnetic resonance imaging (MRI) in detecting retinal detachment (RD) in eyes filled with silicone oil, and to determine the MRI characteristics of silicone oil in vivo. PATIENTS AND METHODS: Seven eyes of seven patients with RD and eight eyes of eight patients without RD after silicone oil surgery were included in the study. All of the patients had clear media. MRI was performed in these patients. The results of ophthalmic examinations were compared with MRI findings. RESULTS: MRI detected six of the seven detached retinas. The multiplanar imaging capability of MRI helped in showing the RDs in various locations. The chemical shift artifact exaggerated the retinal thickness and made the detached retina visible. Fat suppressed images showed the silicone oil-corneal contact clearly. CONCLUSION: MRI is an effective technique for demonstrating RD in eyes filled with silicone oil and can be used successfully in eyes with opaque media.

Adult↗