Holoprosencephaly (lobar form) associated with bilateral vocal cord palsy

There have been many causes associated with bilateral vocal cord palsy, both congenital and perinatal. Until now, the main congenital causes of bilateral vocal cord palsy have been associated with meningomyelocele, Arnold-Chiari malformation, and hydrocephalus. We report a patient with bilateral vocal cord palsy associated with the lobar form of holoprosencephaly. In this case, bilateral vocal cord palsy was caused by the disruption of the cortical laryngeal motoneurons. Neonatal stridor must be carefully evaluated by the neonatologist to exclude severe cerebral anomalies.

A prospective study evidencing rhinomanometric and olfactometric outcomes in women taking oral contraceptives

BACKGROUND

The aim of this prospective study was to evaluate the changes in olfactory sensitivity of oral contraceptive (pill) users.

METHODS

Sixty women underwent rhinomanometric and olfactometric determinations during the follicular, periovular and luteal phases of the menstrual cycle, and at day 7, 14 and 21 of contraceptive intake. Thirty-one women used 30 microg ethinyl oestradiol plus 75 microg gestodene and 29 women used 20 microg ethinyl oestradiol plus 150 microg desogestrel.

RESULTS

Rhinomanometry showed higher but not statistically significant values during the periovular phase than in the follicular and luteal phases. Olfactometry showed a higher sensitivity during the follicular and periovular phases than during the luteal phase of the menstrual cycle. The rhinomanometric surveys in pill users were statistically different from those of the luteal phase (P < 0.02) and the follicular and periovular phases (P < 0.001). The olfactometric thresholds during the period of contraceptive use were statistically different from those of the follicular phase for a few odorous substances, and from those of the periovular phase for each odorous substance, but similar to those of the luteal phase (P = NS).

CONCLUSIONS

Unlike the rhinomanometric airflow and trans-nasal pressure, the olfactory threshold to odours seems to depend on the variations of the ovarian steroids during the menstrual cycle and on the iatrogenic effects of oral contraceptives.

PECAM-1/IgG attenuates peroxynitrite-mediated extremity reperfusion injury

OBJECTIVE

Neutrophil transendothelial migration, a key feature of skeletal muscle ischemia and reperfusion (I/R) injury, is mediated by the platelet endothelial cell adhesion molecule-1 (PECAM-1). Peroxynitrite anion, a toxic product of neutrophil superoxide anion and nitric oxide, contributes to oxidative skeletal muscle injury and can be quantified by measurement of protein tyrosine nitration after I/R. This study hypothesizes that administration of the PECAM-1/IgG antibody chimera will inhibit peroxynitrite-mediated injury after I/R.

METHODS

The study was composed of five groups: an I/R group (n = 4), a sham treatment group anesthetic control (n = 3), a treatment group receiving the PECAM-1/immunoglobulin G (IgG) antibody chimera with I/R (n = 9), a treatment group receiving human IgG with I/R as an antibody control (n = 6), and a treatment group receiving normal saline solution with I/R as a vehicle control (n = 5). The right hind limb in male New Zealand white rabbits was rendered ischemic by occluding the iliac and femoral arteries for 3 hours, followed by 2 hours of reperfusion (I/R). Sham-treated rabbits underwent arterial dissection without arterial occlusion. PECAM-1/IgG-treated rabbits and IgG-treated rabbits received an infusion of 1 mg/kg in normal saline solution 20 mL via an ear vein catheter during the last 5 minutes of ischemia and the first 15 minutes of reperfusion. Saline solution-treated rabbits similarly received normal saline solution 20 mL. The anterior tibialis muscle was harvested after reperfusion. Immunohistochemical staining for nitrotyrosine was performed with monoclonal antinitrotyrosine antibodies and fluorescently labeled secondary antibodies. Computed morphometric study was performed to calculate relative fluorescence scores for each histologic section. Averaged fluorescence scores were analyzed by one-way analysis of variance with Bonferroni post hoc comparison.

RESULTS

The averaged fluorescence scores (mean +/- SEM) for the sham-treated (2.88 +/- 0.78) and PECAM-1/IgG-treated (6.16 +/- 0.43) groups demonstrated a significant reduction in quantitative fluorescence compared with the IgG- (15.17 +/- 2.01) and saline solution-treated (17.46 +/- 3.71) control groups, and the I/R-treated (18.52 +/- 3.00) group, (P <.05).

CONCLUSIONS

These results suggest that PECAM-1/IgG diminishes peroxynitrite-mediated oxidative skeletal muscle injury by inhibiting neutrophil transendothelial migration and may therefore prove a useful therapeutic agent in the treatment of reperfusion injury.

Mortality after carotid body denervation in rats

Carotid body denervation (CBD) in neonatal goats and piglets results in minimal irregular breathing and no fatalities. Redundancy and/or plasticity of peripheral chemosensitivity and a relatively mature ventilatory control system at birth may contribute to the paucity of CBD effects in these species. In the present study, we tested the hypothesis that CBD mortality would be greater in neonates of a less mature species such as the rat. We found that the mortality in rats denervated at 2-3 and 7-8 days of age was significantly higher (P < 0.05) than in sham-CBD rats. In all surviving rats, pulmonary ventilation during hypoxia was lower in CBD than in sham operated rats 2 days after denervation. In surviving rats denervated during the 7th and 8th postnatal days, there was also reduced weight gain and pulmonary ventilation during eupnea, including apneas up to 20 s in duration. However, the effects of CBD were compensated within 3 wk after denervation. Local injections of NaCN indicated that aortic chemoreceptors might have been one of the sites of recovery of peripheral chemosensitivity. We concluded that CBD has higher mortality in newborn rats than in other mammals, possibly because of the relative immaturity of these animals at birth. Nonetheless, in survivors there was enough redundancy and plasticity in the control of breathing to eventually compensate for the consequences of CBD.

[Canaud central venous catheters: 4-year experience]

BACKGROUND

The use of central venous catheters for permanent vascular access has become increasingly important because of the characteristics and the clinical problems of incident patients or patients already undergoing chronic hemodialysis. In this study a short and medium term evaluation was made of a double permanent central venous catheter positioned in the right internal jugular vein. The Canaud catheter was evaluated both from the point of view of practical use and for various technical and clinical problems.

METHODS

During the observation period, July 1995 - September 1999, these catheters were used in 39 patients (mean age 72 years), 22 females and 17 males; 31% were diabetic patients and 46% were older than 75 years. Forty-five catheters were positioned with an average dwelltime of 347 days.

RESULTS

Utilization was almost immediate and the resulting blood flow was suitable for all depurative techniques (blood flow more than 250 ml/min), with an average recirculation of 11.9% and an average resistance index of 0.54. Among the most serious complications during surgery a respiratory block was observed followed by the complete recovery of the patient. Some clinical complications were noted (5 venous thrombosis), as were some technical ones: 12% well as related to problems with the adapter, 24.3% to reversible thrombosis of the catheters occurred in 23 catheters in 22 patients. Infections.

CONCLUSIONS

Overall Canaud catheters appear to represent a valid alternative to other more recent catheters for permanent vascular access. If necessary, they can be easily substituted due to the absence of a subcutaneous cuff.

Tonometry after laser in situ keratomileusis treatment

PURPOSE

To assess the reliability of intraocular pressure measurements by Goldmann applanation tonometry versus pneumotonometry after laser in situ keratomileusis for myopia.

PATIENTS AND METHODS

In this prospective study, corneal Goldmann applanation tonometry and pneumotonometry measurements were made in 118 eyes of 60 patients before and 1 and 3 months after undergoing laser in situ keratomileusis for myopia. Manifest refraction, ultrasonic corneal thickness measurements, and keratometry readings were also obtained.

RESULTS

Preoperative intraocular pressure showed a good correlation between Goldmann applanation tonometry and pneumotonometry values (Pearson r = 0.71; P < 0.001). although Goldmann applanation tonometry readings were slightly higher at low intraocular pressure values and slightly lower at high intraocular pressure values. After a mean stromal ablation depth of 77.1 microm, mean intraocular pressure by Goldmann applanation tonometry decreased significantly (P < 0.001) from a preoperative value of 14.8 +/- 11.9 mm Hg to 11.9 +/- 2.1 mm Hg and 11.7 +/- 1.7 mm Hg after 1 and 3 months, respectively. Mean pre- and post-laser in situ keratomileusis measurements by pneumotonometry were similar (P = 0.8). Differences of postoperative intraocular pressure measurements by Goldmann applanation tonometry and pneumotonometry were statistically significant. After 3 months, there was a poor correlation between Goldmann applanation tonometry and pneumotonometry intraocular pressure values (Pearson r = 0.58). Postoperative intraocular pressure decrease in applanation tonometry correlated with changes in keratometry, spherical equivalent, and central corneal thickness. Regression analysis showed a decrease of 2.9 mm Hg per 70 microm reduction in central corneal thickness.

CONCLUSIONS

Contact pneumotonometry measures the IOP reliably after laser in situ keratomileusis for myopia, whereas Goldmann applanation tonometry underestimates the intraocular pressure. This may be important in the treatment of any future glaucoma.

Multiple rostral medullary nuclei can influence breathing in awake goats

The purpose of this study was to determine the effect on breathing of neuronal dysfunction in the retrotrapezoid (RTN), facial (FN), gigantocellularis reticularis (RGN), or vestibular (VN) nuclei of adult awake goats. Microtubules were chronically implanted to induce neuronal dysfunction by microinjection of an excitatory amino acid (EAA) receptor antagonist or a neurotoxin. The EAA receptor antagonist had minimal effect on eupneic breathing, but 8--10 days after injection of the neurotoxin, 7 of 10 goats hypoventilated (arterial PCO(2) increased 3.2 +/- 0.7 Torr). Overall there were no significant (P > 0.10) effects of the EAA receptor antagonist on CO(2) sensitivity. However, for all nuclei, > or =66% of the antagonist injections altered CO(2) sensitivity by more than the normal 12.7 +/- 1.6% day-to-day variation. These changes were not uniform, inasmuch as the antagonist increased (RTN, n = 2; FN, n = 7; RGN, n = 6; VN, n = 1) or decreased (RTN, n = 2; RGN, n = 3; VN, n = 2) CO(2) sensitivity. Ten days after injection of the neurotoxin into the FN (n = 3) or RGN (n = 5), CO(2) sensitivity was also reduced. Neuronal dysfunction also did not have a uniform effect on the exercise arterial PCO(2) response, and there was no correlation between effects on CO(2) sensitivity and the exercise hyperpnea. We conclude that there is a heterogeneous population of neurons in these rostral medullary nuclei (or adjacent tissue) that can affect breathing in the awake state, possibly through chemoreception or chemoreceptor-related mechanisms.

Severe anaphylaxis induced by latex as a contaminant of plastic balls in play pits

BACKGROUND

Latex causes anaphylaxis in specific contexts among children. We present 2 cases that show that severe reactions may occur in everyday circumstances with latex as a contaminant.

OBJECTIVE

Because 2 cases of severe reactions to latex suggested similar circumstances of exposure, we investigated the immediate environment in which episodes occurred.

METHODS

A 5-year-old girl presented to our casualty department with anaphylaxis after playing in a ball pit filled with approximately 10-cm diameter plastic balls in an American-style fast-food outlet. Two months later, a 9-year-old boy had severe anaphylaxis followed by an asthma attack with loss of consciousness while playing in the playpen of a different outlet belonging to the same company. Latex sensitization was confirmed in both cases by means of skin prick testing, latex glove skin prick testing, and 1-glove finger testing. Immunoblotting of elutions from a ball, the natural rubber latex foam pit lining, and its polyvinyl chloride sheet were performed.

RESULTS

In the girl's immunoblot high levels of IgE specific to Hev b 4, Hev b 7, and Hev b 2 were found. The boy's immunoblot showed positivity to Hev b 7. The polyvinyl chloride ball sample showed a high concentration of specific Hevea species allergen similar to that of the foam layer sample.

CONCLUSION

Severe anaphylaxis can result from contact with latex proteins as a contaminant, rather than as a component, of play area ball pits and therefore outside the reported settings. Emergency health care workers should be aware of this kind of risk. A latex-reduced environment might prevent potentially severe reactions in young customers of fast-food outlets.

[Rapid-detection GBM-ANCA ELISA. An emergency tool for the early diagnosis of type I and II rapidly progressive glomerulonephritis]

Rapidly progressive glomerulonephritides (RPGN) are forms of necrotizing glomerulonephritis associated with anti-glomerular basement membrane (anti-GBM) and anti-neutrophil cytoplasmic antibodies (ANCA) against the antigens proteinase-3 (anti-PR3) and myeloperoxidase (anti-MPO). RPGN have a course of rapid progression to renal failure. We compared the results from the semiquantitative ELISAs for anti-GMB antibodies, PR3-ANCA and MPO-ANCA and the indirect immunofluorescence technique (IIF) against a new rapid assay (30 minutes) for the same antibodies in patients with clinically suspected RPGN. The semiquantitative ELISAs for anti-GBM antibodies and PR3-ANCA and MPO-ANCA have a proven diagnostic significance in patients with RPGN I and III. There were no significant differences between the ANCA-GBM screening test and the results from the semiquantitative ELISAs (p > 0.05). We did not find significant differences between the results for PR3-ANCA and MPO-ANCA from the ANCA-GBM screening test with C-ANCA and P-ANCA IIF values (p > 0.05). We also corroborated that the ANCA-GBM screening test is a diagnostic tool for RPGN I and III as useful as the semiquantitative ELISAs and the IFF technique. The ANCA-GBM ELISA screening test is a tool as useful as the semiquantitative ELISA against anti-GBM antibodies for diagnosis of RPGN I. The comparison of the screening ELISA with the IIF technique and the semiquantitative ELISAs against PR3-ANCA and MPO-ANCA showed similar utility for diagnosis of RPGN III. The advantages of the new screening assay are that three antibodies are tested at the same time, yielding results in only 30 minutes.

Cerebral cortical blood flow during loss of consciousness induced by gravitational stress in rhesus monkeys

We investigated the influence of +Gz acceleration (head-to-foot inertial forces) onset on cerebral cortical blood flow (CBF) of rhesus monkeys to study the mechanisms underlying +Gz-induced loss of consciousness (G-LOC). CBF was measured through a chronic cranial window by laser-Doppler flowmetry and electrodes in contact with the dura mater were used to detect G-LOC (suppression of the cortical electrical activity). The animals were centrifuged up to +12 Gz with different G-onset rate until G-LOC occurred. G-LOC was preceded by a 2-5 s decrease in CBF. At G-LOC detection, CBF was not related to G-onset rate (mean CBF change: -76 +/- 9% of control value). We conclude that G-LOC results from cerebral ischemia rather than from mechanical stresses applied to the brain.

Suicide probability and psychological morbidity secondary to HIV infection: a control study of HIV-seropositive, hepatitis C virus (HCV)-seropositive and HIV/HCV-seronegative injecting drug users

BACKGROUND

Suicide ideation and psychological morbidity among HIV-positive patients has been the object of intense research. No study has investigated this area among injecting drug users (IDUs) infected with HIV and those infected with the hepatitis C virus (HCV), which has the same patterns of transmission of the HIV and may favour HIV replication and, possibly, HIV disease progression.

METHODS

In order to examine the prevalence and characteristics of suicide ideation and psychological morbidity associated with HIV and HCV infection in IDUs, a sample of HIV+ (n=81), HIV-/HCV+ (n=62) and HIV-/HCV- (n=152) subjects completed the Suicide Probability Scale (SPS), The Brief Symptom Inventory (BSI) and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

No difference was found between the groups as far as the mean scores on SPS and the risk of suicide (no-low risk category: 70.7% HIV+, 56.09% HCV+, 65.6% HIV-/HCV-). Estimated psychological morbidity (BSI) (26.9% HIV+, 27.1% HCV+, 25.4% of HIV-/HCV-) and BSI and HADS scores were comparable across the groups.

CONCLUSIONS

Suicide ideation, psychological morbidity and anxiety and depression symptoms seemed not to be directly influenced by HIV-serostatus. Careful assessment of psychological symptoms and suicide ideas among IDUs, as a vulnerable segment of population at risk of HIV and HCV infections, needs to be routinely carried out in clinical settings.

Psychological factors and visual fatigue in working with video display terminals

OBJECTIVES

To examine the part played by psychological factors in complaints about visual health reported by banking officers who work at video display terminals (VDTs).

METHODS

Out of a population of 385 bank workers, a group of 212 subjects without organic visual disturbances (as determined by ophthalmological examination) who share a work environment and job duties was selected. Three questionnaires were administered to these subjects: (a) the NIOSH job stress questionnaire; (b) a questionnaire investigating subjective discomfort related to environmental and lighting conditions of the workplace; (c) a questionnaire on the existence of oculovisual disturbances. Correlation and multiple regression analyses were performed to examine for the presence of predictors of asthenopia.

RESULTS

Social support, group conflict, self esteem, work satisfaction, and underuse of skills were found to be predictors of visual complaints; social support played a part also as a moderating factor in the stress and strain model; this model accounted for 30% of the variance. Subjective environmental factors, although in some cases significantly correlated with asthenopia, were not found to be strong predictors of the symptoms.

CONCLUSIONS

Some part of the complaints about visual health reported by VDT workers are likely indirect expressions of psychological discomfort related to working conditions.

Effect of bioactive aldehydes on cell proliferation and c-myc expression in HL-60 human leukemic cells

Lipid peroxidation produces several toxic carbonyls, including biologically active aldehydes. In previous studies, we demonstrated that 4-hydroxynonenal (HNE), one of the major products of lipoperoxidation, inhibited growth and c-myc expression in K562 and HL-60 human leukemic cells. In this study, we compared the HNE effects with those of 4-hydroxyoctenal (HOE), 4-hydroxyundecenal (HUE; different lengths of the lipophilic tail), and the analogous aldehydes 2-trans-nonanal (lacking the OH group) and nonenal (lacking the OH group and the trans CC double bond), on HL-60 cell proliferation and c-myc expression. HUE and HOE inhibited growth and c-myc expression in a dose-dependent fashion, with an effectiveness comparable with that of HNE, whereas 2-nonenal and nonanal did not affect these parameters. Our results showed that different aldehydes produced from lipid peroxidation may contribute to growth inhibition by c-myc downregulation and that the molecular features involved seem to be the hydroxy group and the trans CC double bond.

Antibodies elicited by naked DNA vaccination against the complementary-determining region 3 hypervariable region of immunoglobulin heavy chain idiotypic determinants of B-lymphoproliferative disorders specifically react with patients' tumor cells

Several reports have suggested that the mechanism of protection induced by antiidiotypic vaccination against low-grade lymphoproliferative disorders is likely to be antibody mediated. Here we test the hypothesis that DNA vaccination with the short peptide encompassing the complementary-determining region 3 hypervariable region of immunoglobulin heavy chain (VH-CDR3) may elicit a specific antibody immune response able to recognize the native antigens in the form required for therapy. As a test system, we used the VH-CDR3 sequences derived from two patients with non-Hodgkin's B lymphomas (PA, AS) and one patient with hairy cell leukemia (BA) to immunize outbred Swiss mice. This experimental model could mimic a clinical setting in which different patients present distinct HLA haplotypes. Individual tumor-specific VH-CDR3 sequences were amplified by a two-step procedure and directly cloned into multigenic plasmid vectors (pRC100 and derived) with and without mouse interleukin 2 (mIL-2). Each tumor-specific sequence was characterized by sequencing. Female Swiss mice were vaccinated i.m. with plasmids expressing the tumor-specific VH-CDR3 sequence alone (pRC101-PA), mIL-2 plus the VH-CDR3 sequence (pRC111-PA), or a different unrelated antigen (NS3 of hepatitis C virus; pRC112), the sole mIL-2 (pRC110), and the empty plasmid (pRC100). Boost injections were performed at 3 and 16 weeks from the first vaccination, and sera were drawn before each vaccination and at 6, 9, and 19 weeks. Induction of anti-VH-CDR3s antibodies in the sera and their ability to recognize native antigens on patients' tumor cells were evaluated by FACS analysis. Up to 56% (n = 25) of mice vaccinated with pRC111-PA plasmid and 20% (n = 15) of mice vaccinated with pRC101-PA developed a specific immune response that was maintained throughout 19 weeks of observation in 40% of pRC111-PA-vaccinated mice. No response was detected in sera obtained from mice vaccinated with the other plasmids (n = 45). pRC111-PA injection s.c. was less effective (13%, n = 15) than i.m. injection (53%, n = 15). Indeed, we demonstrated that antibodies elicited by naked DNA vaccination against three different patient-derived VH-CDR3 peptides (pRC111-PA or BA or AS) readily reacted with binding epitopes on the idiotypic proteins expressed on the surface of tumor cells derived from each patient; 60, 40, and 40% of, respectively, PA-, BA-, and AS-vaccinated mice developed specific antibodies. No cross-reactivity was detected among the three different CDR3s against tumor cells derived from the other two patients. The outbred mouse strategy confirmed the significant matching potential of three different VH-CDR3 peptides to be efficaciously presented through different MHCs. We conclude that individual VH-CDR3 DNA vaccination can result in a potentially effective specific immune response against non-Hodgkin's B lymphoma cells by a rapid and low-cost therapeutic approach.

Comparison of MRI, EEG, EPs and ECD-SPECT in Wilson's disease

OBJECTIVES

The purpose of this study is to evaluate the efficiency of a few methodologies in detecting anatomo-functional brain abnormalities in patients with Wilson's disease.

MATERIALS AND METHODS

Twenty-three patients with Wilson's disease underwent almost simultaneously brain magnetic resonance imaging (MRI), computerized electroencephalography (EEG), multimodal evoked potentials (EPs) and ECD single photon computerized tomography (SPECT) evaluation. The clinical picture was of the neurologic type in 8 patients and of the hepatic type in 15.

RESULTS

MRI was abnormal in 7 patients with neurological manifestations. The EPs proved pathologic in 7 neurologically symptomatic patients and in 4 cases with hepatic form. These results agree with those reported in other case studies. The EEG records were abnormal only in 3 cases. Nevertheless, the most interesting finding of this study is the particular frequency (86%) of diffuse or focal decrease of ECD uptake shown by brain SPECT.

CONCLUSION

We highlight the use of this interesting procedure in the therapeutic monitoring of this disease.

Non-confluent pulmonary arteries in a patient with pulmonary atresia and intact ventricular septum: ? A 5th aortic arch with a systemic-to-pulmonary arterial connection

Major abnormalities of pulmonary circulation are uncommon in the patient with pulmonary atresia and intact ventricular septum. Non-confluent pulmonary arteries have only rarely been described in this setting. In this case report, we describe a patient in whom the pulmonary arteries are non-confluent, with the right pulmonary artery supplied through a right-sided arterial duct, and the left pulmonary artery most likely through a fifth aortic arch, thus providing a systemic-to-pulmonary arterial connection. We discuss the various forms of non-confluent pulmonary arteries in the setting of pulmonary atresia and intact ventricular septum.

Maternity advice survey: sleeping position in Eastern Europe. MAS Study Group for WHO EURO region

AIM

To identify hospitals in Eastern Europe promoting front infant sleeping position.

METHODS

Questionnaires were distributed to maternity units in 22 countries during July to November 1999.

RESULTS

A total of 489 hospitals in 20 countries responded. Preferred position in normal care units was back (26.6%), front (1. 8%), side (65%), or combination/none (6.6%). Corresponding recommendations at discharge were 17.4%, 3.5%, 73%, and 6.1%.

[Permanent central venous catheters for dialysis. The situation in Piedmont-Aosta Valley]

BACKGROUND

Permanent central venous catheters for hemodialysis have become increasingly important as vascular accesses for extracorporeal dialysis. The aim of this study was to evaluate the prevalence and various aspects of these catheters in the chronic dialysis population in Piedmont and Aosta Valley on 30-6-1998 using a multiple-choice questionnaire.

METHODS

A total of 2389 patients were receiving chronic hemodialysis. Permanent central venous catheters were present in 6.2% of the population (149 patients), arteriovenous fistulas in 83.1%, vascular prostheses in 9.3% and temporary catheters in 1.4%. The site chosen for permanent catheters was the internal jugular vein in 88.6% of cases, the subclavian vein in 8.7% of cases and the femoral vein in 2.7% of cases. The double catheter is the most frequently used. In 76% of centres catheters are positioned by nephrologists. Thrombosis prophylaxis is performed in 98% of cases with heparin and the most frequently used disinfectant to dress the cutaneous exit is iodopovidone.

RESULTS

This study highlights the important role played by permanent catheters. The double catheter was used in 64.4% of the entire population, confirming the greater efficiency of these catheters as reported in the literature. Operating autonomy is relative in 76.2% of centres where catheters are positioned by nephrologists who often use the collaboration of other specialists.

CONCLUSIONS

The authors stress the need to reflect on the use of iodopovidone is to dress the cutaneous exit of catheters since this disinfectant is contraindicated by one of the largest manufacturers of silicone catheters owing to its harmful medium long-term effects.