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At least 217 records · Page 12Linked to original sources

A method for the determination of syringe needle punctures in rubber stoppers using stereoscopic light microscopy.

The ability to accurately determine the number of syringe needle penetration holes through the rubber stoppers in pharmaceutical vials and rubber septa in intravenous (i.v.) line and bag ports has been a critical factor in a number of forensic cases involving the thefts of controlled substances or suspected homicide by lethal injection. In the early 1990s, the microscopy and microanalysis group of the U.S. Food and Drug Administration's Forensic Chemistry Center (FCC) developed and implemented a method (unpublished) to locate needle punctures in rubber pharmaceutical vial stoppers. In 1996, as part of a multiple homicide investigation, the Indiana State Police Laboratory (ISPL) contacted the FCC for information on a method to identify and count syringe needle punctures through rubber stoppers in pharmaceutical vials. In a joint project and investigation using the FCC's needle hole location method and applying a method of puncture site mapping developed by the ISPL, a systematic method was developed to locate, identify, count, and map syringe punctures in rubber bottle stoppers or i.v. bag ports using microscopic analysis. The method requires documentation of punctures on both sides of the rubber stoppers and microscopic analysis of each suspect puncture site. The final result of an analysis using the method is a detailed diagram of puncture holes on both sides of a questioned stopper and a record of the minimum number of puncture holes through a stopper.

Cause of Death↗

A prospective randomised study of local anaesthetic injection after multiple rubber band ligation of haemorrhoids.

One hundred and forty-two patients with second and third degree internal haemorrhoids were randomised to rubber band ligation only (n = 72) or rubber band ligation + local anaesthetic injection (n = 70). Pain was assessed by the patients at intervals of 6 hours and 1, 2, 3 and 4 days after banding. Other symptoms, complications, analgesic requirements and patient satisfaction were also recorded for 10 days following the treatment. There was a significant reduction in pain at 60 minutes and 6 hours after the procedure in the rubber band ligation plus local anaesthetic injection patients compared with the rubber band ligation only group (P < 0.05), but there was no reduction in pain when local anaesthetic was used compared with rubber band ligation only on days 1, 2, 3 and 4 days after ligation. On day 10 after banding, there was no difference between the two groups with respect to symptoms such as nausea, feeling of heaviness and/or tenesmus, fainting; complications, analgesic consumption or overall patient satisfaction. Bupivacaine injection after multiple rubber band ligation may be useful in reducing pain during the first 6 hours of the postbanding period.

Adult↗

[Hypersensitivity to rubber].

Occupational contact dermatitis caused by rubber chemicals is described in two groups of patients. The first group consisted of personnel from the operating rooms of a university hospital. In 12 persons the contact allergic reactions appeared to be mainly due to rubber chemicals of the thiuram group of compounds. The second group consisted of cattle farmers. In 6 persons patch tests could be performed. The main cause of the rubber contact on the farms appeared to be the milking machine. The antioxydants in the heavy duty rubber of these machines are of the paraphenylenediamine group of compounds. Positive patch tests were found to N-phenyl-N' -cyclohexylparaphenylenediamine (CPPD) and to the closely related N-phenyl-N'-isopropylparaphenylenediamine (IPPD). Their use in rubber of milking machines in Europe is based on the german "Mitteilungen aus dem Bundesgesundheitsamt" which permits the incorporation of IPPD in these kind of rubber parts to a percentage of 1,5%.

Bandages↗

Spontaneous abortions among rubber workers and congenital malformations in their offspring.

Spontaneous abortions of hospitalized women and congenital malformations were analyzed among rubber workers to investigate the possibility of an association between reproductive problems and chemical exposures in the rubber industry. Information on workers was obtained from the membership register of the Union of Rubber and Leather Workers and from the personnel register of a rubber factory. The frequencies of spontaneous abortions did not appreciably differ when the pregnancies occurred during Union membership or during employment in the factory as compared with the pregnancies occurring before or after that time. A case-referent study concerning the association between different exposures and spontaneous abortions showed that the odds ratio for factory workers exposed to rubber chemicals was increased in the footwear department. A corresponding risk was not observed in the tire department. The contradictory observations may be explained by concomitant exposure to solvents in the footwear department or by other nonoccupational factors. The possible association between congenital malformations and exposures in the rubber and leather industries was studied by the case-referent technique. No significant increase in the risk of malformations was observed in any branch of employment. However, the numbers of malformations were rather small.

Abnormalities, Drug-Induced↗

Comparison of rubber band ligation and sclerosant injection for first and second degree haemorrhoids-- a prospective clinical trial.

Fifty patients with first or mild second degree haemorrhoids were randomly allocated to sclerosant injection (26) or rubber band ligation (24). One year after treatment 24 injection and 22 rubber band ligation patients were assessed. All patients presented with rectal bleeding; injection relieved 14 and rubber band ligation relieved 17 of this symptom (N.S.). Three of seven patients with prolapsing haemorrhoids who had sclerosant injections and five of seven who had rubber band ligation were relieved of this prolapse. However, a further six patients in the injection group developed prolapse for the first time during the one year follow-up period (p less than 0.05). Rubber band ligation relieved anal pain in 10 out of 14 patients whereas injection relieved only one patient of this symptom (p less than 0.05). Neither treatment influenced pruritus ani or faecal soiling. Although rubber band ligation caused more treatment discomfort, it is an effective management for first and mild second degree haemorrhoids and it should be considered as the procedure of choice.

Adult↗

[Allergic reaction to products made of natural rubber].

In the previous few years, there has been a startling escalation in intraoperative and radiologic anaphylactic episodes, some of them lethal, that have been assigned to rubber exposure. Immediate hypersensitivity reactions to natural rubber pose a significant risk to patient with spina bifida and urogenital abnormalities, health care workers, and rubber industry workers. It has been estimated that 2% to 10% of physicians and nursing personnel are latex allergic. The clinical syndromes associated with reactions to latex may be divided into three broad categories a) contact dermatitis--limited to skin directly in contact with latex, b) contact urticaria syndrome a broad spectrum of contact reactions including not only immediate wheal and flare reactions, but also dyshidrotic vesiculation, and accelerated contact reactions including erythema, burning or pruritus occurring within 10-30 minutes after contact, c) systemic allergic reactions-including generalized urticaria or pruritus, rhinoconjunctivitis or asthma, as well as the multiple presentations of anaphylaxis. Contact dermatitis reactions are thought to be a T-cell mediated type IV reaction, systemic reactions to latex appear to be an IgE-mediated phenomenon. Contact urticaria syndrome seems to be a heterogeneous group of reactions. Diagnosis of latex allergy is made on clinical grounds, however, history alone is insufficient to recognize all patients at risk, and conscientious testing materials are not yet available. Prick tests utilizing extracts from latex gloves or from raw latex preparation can be used but the specificity of this test remains unknown. Skin prick testing must be considered experimental and should be only done by experienced physician. Serologic testing for latex allergy remains a safe alternative, although the sensitivity and specificity of this procedure is still undefined. Prophylactic regimes to avoid rubber exposure and decrease the antigen content of natural rubber products by the rubber industry should be implemented to decrease the rate of sensitization in the future and prevent allergic reactions.

Anaphylaxis↗

A randomized trial to compare rubber band ligation with phenol injection for treatment of haemorrhoids.

A prospective randomized trial has compared rubber band ligation with phenol injection in 82 patients with symptomatic haemorrhoids. The symptomatic results in all patients 12 months after treatment were indistinguishable, 64 per cent being improved after rubber band ligation, compared with 70 per cent after injection. Complications of treatment were recorded in 5 patients after rubber band ligation, 3 of whom required hospital admission compared with one minor complication after infection. However, repeated treatment was necessary in 13 patients after phenol injection compared with only 4 following rubber band ligation (P less than 0.05). Additional treatment was necessary in 6 patients from each group. Two-thirds of patients with third-degree piles required additional therapy. It is concluded that rubber band ligation and injection provide similar results, but rubber band ligation is more liable to complications with inexperienced operators.

Female↗

Cloning and characterization of cDNA encoding farnesyl diphosphate synthase from rubber tree (Hevea brasiliensis).

Commercially used natural rubber (cis-1,4-polyisoprene) is a secondary metabolite of the rubber tree (Hevea brasiliensis). Previous studies have shown the involvement of a prenyl transferase in the final steps of natural rubber biosynthesis which includes polymerization of isopentenyl pyrophosphate into rubber. Using synthetic oligonucleotides corresponding to the partial amino acid sequences of this protein as probes to screen a laticifer-specific cDNA library, we have isolated a full-length cDNA which encodes a 47 kDa protein with strong homology to farnesyl diphosphate synthases from many species. The catalytic activity of this protein was confirmed by complementing the deletion yeast mutant. In Hevea, this gene is expressed in latex producing cells and in the epidermal region of the rubber plant suggesting a dual role for the protein in the biosyntheses of rubber and other isoprenoids. Although the expression level of this gene is not significantly affected by hormone treatment (e.g. ethylene), regeneration of latex due to tapping increases its expression level.

Alkyl and Aryl Transferases↗

Rubber band ligation for hemorrhoidal disease can be safely performed in select HIV-positive patients.

PURPOSE: Many surgeons have abandoned the use of rubber band ligation for the treatment of hemorrhoids in patients infected with human immunodeficiency virus because of the belief that this procedure could lead to disastrous outcomes. This study was designed to evaluate the safety and efficacy of rubber band ligation in otherwise healthy human immunodeficiency virus-positive patients. METHODS: A retrospective chart review of healthy human immunodeficiency virus-positive patients who underwent rubber band ligation for symptomatic hemorrhoids between April 1993 and May 2000 was conducted. RESULTS: The study group comprised 11 patients. All patients were male, with a median age of 48 (range, 32-64) years. Mean T-cell helper count was 450 (range, 200-1,000) cells/microl. A median of 2 (range, 1-4) rubber band ligations were performed per patient. The median length of follow-up was seven (range, 1-28) months. There were no deaths or complications in any study group patient. Eight patients (73 percent) had excellent results, with complete resolution of symptoms. Two patients (18 percent) had initial improvement but subsequently had hemorrhoidectomy because of recurrent symptoms. Only one patient (9 percent) had no benefit from rubber band ligation and underwent hemorrhoidectomy. CONCLUSION: These data suggest that asymptomatic human immunodeficiency virus-positive patients can be treated safely and effectively with rubber band ligation for symptomatic hemorrhoids.

Adult↗

Long-term outcome of rubber band ligation for symptomatic primary and recurrent internal hemorrhoids.

PURPOSE: Rubber band ligation therapy for symptomatic hemorrhoidal disease has been used for many years and is a well-accepted treatment modality, but information on long-term outcome is limited. Our goals were to determine safety and long-term efficacy of this treatment. METHODS: A retrospective chart review of patients undergoing rubber band ligatures for symptomatic internal hemorrhoids in a single practice was conducted. Information on presenting symptoms, number of bands applied, response to therapy, complications encountered, length of follow-up, interval to recurrent symptoms when applicable, and subsequent therapy were documented. Supplemental information was obtained from telephone follow-up. Outcome was categorized as success or failure, in which success was defined as: permanent relief of symptoms for follow-up period; marked improvement in symptomatology with rare manifestation of bleeding (< or = 1/month); symptom relief for a limited period of time (> or = 100 days), and failure was defined as: modest improvement (decreased but not relief of symptoms); or no improvement in symptoms. RESULTS: A total of 805 patients underwent 2,114 rubber band ligatures. Most common presenting symptoms were bleeding in 731 patients (90.8 percent) and prolapsing in 382 patients (47.5 percent). The median number of bands placed was two (range, 1-17). The median time between bandings was 4.7 (range, 1.1-35.6) weeks. Median follow-up time was 1,204 (range, 14-9,571) days. Excluding 104 patients lost to follow-up (never returned after initial treatment), success was obtained in 70.5 percent (494/701) and failure in 29.5 percent (207/701) of patients. Success rates were similar for all degrees of hemorrhoids. Hemorrhoidal disease requiring the placement of four or more bands was associated with a trend in higher failure rates and greater need for subsequent hemorrhoidectomy. Complications per treatment series included bleeding (2.8 percent), thrombosed external hemorrhoids (1.5 percent), and bacteremia (0.09 percent). Higher bleeding rates were encountered with the use of acetylsalicylic acid/nonsteroidal anti-inflammatory drugs and warfarin. Time to recurrence was less with subsequent treatment courses. Treatment of recurrent symptoms with rubber band ligation resulted in success rates of 73.6, 61.4, and 65 percent for first, second, and third recurrences respectively. This resulted in a cumulative success rate of 80.2 percent for this method of treatment. CONCLUSIONS: Rubber band ligatures are safe and effective therapy for symptomatic internal hemorrhoids. It can be used to treat all degrees of hemorrhoids with similar effectiveness. The likelihood of success is lower if more than four bands are needed to eliminate symptoms. The use of acetylsalicylic acid/nonsteroidal anti-inflammatory drugs and warfarin is associated with higher bleeding rates. Rubber band ligatures for recurrence of symptoms is effective; however, time to recurrence is less with subsequent treatments.

Adult↗

Chrome-tanned leather shavings as a filler of butadiene-acrylonitrile rubber.

The noxious wastes from the tanning industry such as chrome-tanned leather shavings were used as the only filler of rubber mixes containing carboxylated butadiene-acrylonitrile rubber (XNBR) or butadiene-acrylonitrile rubber (NBR), and a dispersing agent Limanol PEV (Schill & Seilacher). The best form addition of leather powder to the rubber mixes is mixed the waste protein with zinc oxide. The leather powder added to the rubber mixes improves the mechanical properties: tensile strength (T(s)), elongation at break (epsilon(b)) and increase the cross-linking density of carboxylated XNBR and NBR rubber mixes. Satisfactory results of these studies are presented in this work.

Acrylic Resins↗

In vitro and in vivo antimicrobial activity of covalently coupled quaternary ammonium silane coatings on silicone rubber.

Biomaterial-centered infection is a dreaded complication associated with the use of biomedical implants. In this paper, the antimicrobial activity of silicone rubber with a covalently coupled 3-(trimethoxysilyl)-propyldimethyloctadecylammonium chloride (QAS) coating was studied in vitro and in vivo. Gram-positive Staphylococcus aureus ATCC 12600, Staphylococcus epidermidis HBH, 102, and Gram-negative Esherichia coli O2K2 and Pseudomonas aeruginos AK1 were seeded on silicone rubber with and without QAS-coating, in the absence or presence of adsorbed human plasma proteins. The viability of the adherent bacteria was determined using a live/dead fluorescent stain and a confocal laser scanning microscope. The coating reduced the viability of adherent staphylococci from 90% to 0%), and of Gram-negative bacteria from 90% to 25% while the presencc of adsorbed plasma proteins had little influence. The biomaterials were also subcutaneously implanted in rats for 3 or 7 days, while pre- or postoperatively seeded with S. aureus ATCC 12600. Preoperative seeding resulted in infection of 7 out of 8 silicone rubber implants against 1 out of 8 QAS-coated silicone rubber implants. Postoperative seeding resulted in similar infection incidences on both implant types, but the numbers of adhering bacteria were 70% lower on QAS-coated silicone rubber. In conclusion, QAS-coated silicone rubber shows antimicrobial properties against adhering bacteria, both in vitro and in vivo.

Adsorption↗

Occupational rubber glove allergy: results of the Information Network of Departments of Dermatology (IVDK), 1995-2001.

About 21% of the patients with occupational contact dermatitis registered in the Information Network of Departments of Dermatology (IVDK) in the years 1995-2001 were patch tested due to suspected rubber glove allergy. We analysed reaction frequencies to thiurams, dithiocarbamates, mercaptobenzothiazole (MBT) and its derivatives, thioureas, and 1,3-diphenylguanidine (1,3-DPG). Thiurams were by far the most frequent rubber allergens in these patients (16.2% positive reactions, age- and sex-standardized), and the reaction frequency showed a decline from 20.9% in 1997 to 12.8% in 2000. However, this trend was not statistically significant, and was followed by an increase to 16.5% in 2001. All other rubber allergens showed no time trend at all. Although, according to manufacturers' information, the use of dithiocarbamates and MBT derivatives in rubber glove production increased in recent years, these allergens elicited positive reactions in only about 3% of the patients tested, and showed no increasing trend. Thioureas and 1,3-DPG are not widely used in rubber glove production, and play only a minor role in rubber glove contact allergy. Most of the positive reactions to 1,3-DPG are probably false-positive, irritant reactions.

Adult↗

Visual evaluation of train-of-four and double burst stimulation, fade at various currents, using a rubber band.

The sensitivity of train-of-four (TOF) or double burst stimulation3,3 (DBS3,3) was examined to detect fade by visual inspection, at varying stimulating currents, using the thumb of the investigated arm maintained abducted by the use of a rubber band. One-hundred adult patients were allocated randomly to (1) train-of-four-rubber band (TOF-RB), (2) train-of-four-control (TOF-control), (3) double burst stimulation-rubber band (DBS-RB), or (4) double burst stimulation-control (DBS-control) group. Each group contained 25 patients. The thumb of the investigated arm was kept abducted using a rubber band in the TOF-RB band and DBS-RB group and was free in the TOF-control and DBS-control. TOF stimuli were delivered in the TOF-RB and TOF-control groups, and DBS3,3 in the TOF-RB and TOF-control at 50, 30 and 20 mA. The probability of visual detection of TOF fade was the same in the TOF-RB and TOF-control groups. In contrast, when measured TOF ratio was 0.51-0.80, at the stimulating current of 50 or 30 mA, the likelihood of visual detection of fade in the DBS-RB group was significantly higher than in the DBS-control group (P < 0.05). With a TOF ratio of 0.61-0.70, in the DBS-RB group the probability of visual detection of fade at 50 or 30 mA was significantly higher than at 20 mA (P < 0.05). This study suggests that when using a rubber band, fade in response to the DBS3,3 is detected by visual inspection more readily at a stimulating current of 50 or 30 mA than without the rubber band.

Adult↗

Roller pump induced tubing wear of polyvinylchloride and silicone rubber tubing: phase contrast and scanning electron microscopic studies.

Tubing wear and spallation have long been recognized as complications of roller pumps used in cardiopulmonary bypass (CPB) although the reported results of studies of polyvinylchloride (PVC) and silicone rubber tubing wear are still controversial. We conducted phase-contrast microscope (PCM) and scanning electron microscope (SEM) studies of roller pump induced tubing wear. A closed CPB circuit was constructed, and both PVC and silicone rubber tubing (1/2 inch internal diameter [ID]) were tested under normal and tight occlusions of a dual roller pump at a typical CPB flow rate (4,500 ml/min) for 1, 2, 4, and 6 h in quintet. After each pump run, the tubing was removed. It was first examined with PCM, and suspicious portions were then analyzed in detail using SEM. In silicone rubber tubing of longer running time, the external diameter often decreased. Wear was invariably found on the luminal surfaces at the junction of the inner and outer walls of both the PVC and silicone rubber tubing with no significant differences between normal and tight occlusion. The grooves in the PVC tubing were narrow and continuous with occasional deep cracks in the tubing after more than 3 h of pump run. The grooves in the silicone rubber tubing were wide and often interrupted with occasional V-shaped elevated areas. Craters of less than 50 microns occurred sporadically in both types of tubing. Neither PVC nor silicone rubber tubing offers advantages in terms of roller pump induced tubing wear and spallation.

Cardiopulmonary Bypass↗

Peribiliary plexa--important pathways for shunting of iodized oil and silicon rubber solution from the hepatic artery to the portal vein. An experimental study in rats.

OBJECTIVES: Iodized oil is commonly used in chemoembolization of hepatic tumors, and silicon rubber solution is used for casting studies of hepatic tumor vasculature. Understanding the distribution patterns of iodized oil and silicon rubber solution is of significance in the refinement of iodized oil techniques and proper interpretation of hepatic tumor vascular studies. In this study, the location for iodized oil and silicon rubber solution shunting from the hepatic artery to the portal vein was identified. METHODS: Iodized oil and silicone rubber solution were injected into the hepatic artery in rats. The porta hepatis and the liver periphery were examined using in vivo microscopy. RESULTS: Iodized oil and silicone rubber solution had identical distribution patterns in the hepatic circulation. Both were shunted in large quantities from the hepatic artery into the portal vein through the peribiliary plexa. Other potential shunting sites did not contribute to the shunting. CONCLUSIONS: Though of different chemical natures, iodized oil and silicon rubber solution share similar distribution patterns in the liver. Hepatic arterioportal shunting of these substances occurs via the peribiliary plexa.

Animals↗

Inhibition of microbial adhesion to silicone rubber treated with biosurfactant from Streptococcus thermophilus A.

Microbial adhesion of four bacterial and two yeast strains isolated from explanted voice prostheses to silicone rubber before and after conditioning with a biosurfactant obtained from the probiotic bacterium Streptococcus thermophilus A was investigated in a parallel plate flow chamber. The silicone rubber with and without an adsorbed biosurfactant layer was characterized using contact angle measurements. Water contact angles indicated that the silicone rubber surface with adsorbed biosurfactant was more hydrophilic (58 degrees) than bare silicone rubber (109 degrees). The results obtained showed that the biosurfactant was effective in decreasing the initial deposition rates, and the number of bacterial cells adhering after 4 h, for all microorganisms tested. A decrease in the initial deposition rate was observed for Rothia dentocariosa GBJ 52/2B and Staphylococcus aureus GB 2/1 from 1937+/-194 to 179+/-21 microorganisms cm(-2) s(-1) and from 1255+/-54 to 233+/-26 microorganisms cm(-2) s(-1), respectively, accounting for an 86% reduction of the initial deposition rate for both strains. The number of bacterial cells adhering to the silicone rubber with preadsorbed biosurfactant after 4 h was further reduced by 89% and 97% by the two strains, respectively. The two yeast strains tested showed less reduction in adhesion after 4 h, to values between 67% and 70%. Such a pretreatment with surface-active compounds may constitute a promising strategy to reduce the microbial colonization rate of silicone rubber voice prostheses.

Bacterial Adhesion↗

Prehistoric polymers: rubber processing in ancient mesoamerica

Ancient Mesoamerican peoples harvested latex from Castilla elastica, processed it using liquid extracted from Ipomoea alba (a species of morning glory vine), and fashioned rubber balls, hollow rubber figurines, and other rubber artifacts from the resulting material. Chemical and mechanical analyses of the latex and of the processed rubber indicate that the enhanced elastic behavior of the rubber relative to the unprocessed latex is due to purification of the polymer component and to an increase in the strength and number of interchain interactions that are induced by organic compounds present in I. alba. These ancient peoples' control over the properties of latex and processed rubber gave rise to the Mesoamerican ball game, a central ritual element in all ancient Mesoamerican societies.

Journal Article↗