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Biomedical subjects

M Snir

Publications and source records attributed to M Snir.

At least 19 recordsLinked to original sources
PubMed2006

Combined propofol sedation with sub-Tenon's lidocaine/mercaine infusion for strabismus surgery in adults.

AIMS: To evaluate the safety and efficacy of propofol sedation combined with sub-Tenon's anaesthesia for strabismus surgery in adults. METHODS: Thirty-two consecutive patients aged 31-85 years underwent strabismus surgery under general (n=16) or local (n=16) anaesthesia. In the local anaesthesia (study) group, sedation was induced with a loading dose of midazolam, fentanyl, and propofol, followed by continuous infusion of propofol, 3-6 mg/k/h to deep sedation. A nasal tube was inserted to prevent airway obstruction. Sub-Tenon's anaesthesia included infusion of a 3-4 ml mixture (50 : 50) of lidocaine 2%/mercaine 0.5%. General anaesthesia consisted of premedication with midazolam, followed by fentanyl, esmeron-bromate, propofol, and tracheal intubation. Duration of surgery and anaesthesia, intraoperative oculocardiac reflex and arrhythmias, time to discharge, postoperative pain, nausea and vomiting, and patient and surgeon satisfaction were evaluated. RESULTS: The local anaesthesia group had a significantly shorter operative and anaesthesia time, fewer episodes of oculocardiac reflex or arrythmia/bradycardia requiring treatment, fewer early or late episodes of nausea and vomiting, and less pain. The patients and surgeon in this group reported higher satisfaction. CONCLUSION: Propofol sedation with local sub-Tenon's injection of lidocaine/mercaine is recommended for the induction and maintenance of anaesthesia during unilateral or bilateral strabismus surgery in adults. The method is quick and effective, without systemic or ocular side effects.

Adult↗
PubMed2006

Effect of peripheral retinal ablation with cryotherapy versus diode laser photocoagulation on axial length in the growing rabbit eye.

AIMS: To evaluate and compare the effects of peripheral retinal cryotherapy and diode laser photocoagulation on axial length, anterior chamber depth, and lens thickness in developing rabbit eyes. METHODS: 26 eyes of 6 week old Abbit rabbits were randomly assigned to undergo laser photocoagulation or cryotherapy of the peripheral retina. Eight eyes of four untreated rabbits served as controls. Biometric and intraocular pressure measurements were performed at 0, 5, and 10 weeks after treatment. RESULTS: Five rabbits died, leaving 10 rabbits (20 eyes) in the study group and two (four eyes) in the control group. Average axial lengths for the control, laser treated, and cryo treated eyes were 15.72 mm, 16.08 mm, and 16.11 mm, respectively, at baseline and 17.48 mm, 18.09 mm, and 19.4 mm, respectively, at 10 weeks after treatment (p = 0.028, paired Wilcoxon test). Anterior chamber depth increased from 2.2 mm to 2.5 mm in both treatment groups, and from 2.14 mm to 2.28 mm in the control group. Lens thickness averaged 5.11 mm in the control group and 5.38 mm in the treatment groups before treatment, and 6.34 mm, 6.31 mm, and 6.38 mm, respectively, 10 weeks after treatment. CONCLUSIONS: Peripheral retinal cryotherapy causes a significantly greater elongation of the eye compared to diode laser photocoagulation in a rabbit model.

Animals↗
PubMed2005

Establishing a master's degree programme in bioinformatics: challenges and opportunities.

The development of the Bioinformatics MS degree program at the University of Illinois, the challenges and opportunities associated with such a process, and the current structure of the program is described. This program has departed from earlier University practice in significant ways. Despite the existence of several interdisciplinary programs at the University, a few of which grant degrees, this is the first interdisciplinary program that grants degrees and formally recognises departmental specialisation areas. The program, which is not owned by any particular department but by the Graduate College itself, is operated in a franchise-like fashion via several departmental concentrations. With four different colleges and many more departments involved in establishing and operating the program, the logistics of the operation are of considerable complexity but result in significant interactions across the entire campus.

Biomedical Engineering↗
PubMed2005

Augmented trabeculectomy in paediatric glaucoma.

AIMS: To report the experience with trabeculectomy augmented with mitomycin C and 5-fluorouracil for the treatment of paediatric glaucoma. METHODS: Retrospective, interventional case series design was used. The sample included 17 children (29 eyes) with primary (19 eyes) or secondary (10 eyes) glaucoma who were treated with augmented trabeculectomy as the primary procedure between 1990 and 2002. Data were collected on age and family history, preoperative and end of follow up intraocular pressure, cup/disc ratio (evaluated by drawing), visual acuity, complications, and post-surgery treatment. RESULTS: Patient age at surgery ranged from 1 month to 8 years; most patients (n = 14, 82.3%) were aged less than 1 year (range 1 month-8 months, mean 3.95 (SD 2.56) months); three patients (17.7%) were aged 3, 5, and 8 years. The duration of follow up was 3-120 months (mean 46 months). Intraocular pressure significantly improved from 21 mm Hg to 60 mm Hg (mean 33.1 (10) mm Hg) before surgery to 6-26 mm Hg (mean 17.1 (6) mm Hg) after, (p <0.0001). There was no significant change in cup/disc ratio: 0.1-0.8 (mean 0.42 (0.26)) before and 0.1-1.0 (mean 0.511 (0.27)) after (p = 0.45). In 22 eyes (75.8%), intraocular pressure was controlled at less than 20 mm Hg and the cup/disc ratio remained stable or improved. The life table success rate for intraocular pressure control remained stable at 86% at the 12, 24, and 36 months and after 48 months decreased to 53%. There was no significant difference in the life table results between primary and secondary glaucoma. 14 eyes (48.2%) had a visual acuity better than 20/120 by the end of follow up. Repeated surgery was necessary in eight eyes (27.5%), and additional antiglaucoma treatment in 13 (44.8%). Complications included retinal detachment 1 year after surgery, choroidal detachment, and blebitis (one eye each). CONCLUSIONS: Augmented trabeculectomy with mitomycin C and 5-fluorouracil may serve as the primary procedure in a selected group of paediatric patients with glaucoma.

Antimetabolites↗
PubMed2004

Refraction and keratometry in 40 week old premature (corrected age) and term infants.

AIM: To compare refraction and keratometry readings between premature and term babies at 40 weeks' postconceptional age (PCA), and the possible effect of birth weight (BW) and gestational age (GA) on ocular parameters. METHODS: 33 preterm babies hospitalised in the neonatal unit between January and March 2002 were matched with 33 term babies born within the same period and hospitalised in the same unit. The preterm group underwent funduscopy at 4-5 weeks after delivery. Ophthalmic examination at 40 weeks' PCA included cycloplegic retinoscopy, funduscopy, and keratometric measurements. Mean and standard deviation of refraction, astigmatic power (plus cylinder), axis of astigmatism, and keratometric reading were calculated and compared between groups and correlated with BW and GA in the premature babies. RESULTS: Retinopathy of prematurity (ROP) stage 1 or 2 was noted in 88% of the premature babies on the first funduscopy examination, but only in 36% by the corrected age of 40 weeks. Statistically significant between groups differences were found for cycloplegic refraction (p = 0.02 for both eyes) and keratometry (p = 0.001 for both eyes). GA and BW had no impact on the refractive and keratometric findings in the preterm babies. CONCLUSIONS: Babies with mild ROP at the corrected age of 40 weeks have mild hypermetropia compared to the moderate hypermetropia found in term babies (a difference of 50%), and they have higher and steeper keratometric values. The greater corneal curvature may contribute to the development of myopia. Ophthalmologists and parents need to be aware of the possibility of visual dysfunction already very early in life even in relatively older premature infants.

Astigmatism↗
PubMed2004

Keratometry measurements in preterm and full term newborn infants.

AIM: To evaluate the relation between postconceptional age and birth weight with keratometric values in preterm and full term infants. METHODS: A prospective cross sectional study was performed. The cohort included 99 infants (198 eyes) admitted to the Neonatal and Neonatal Intensive Care Units at Schneider Children's Medical Center of Israel from February to September 2002. Keratometry in the horizontal and vertical meridians was performed in both eyes of each infant by two ophthalmologists using an autokeratometer. The results were evaluated according to: postconceptual age (<32 weeks, 32-36 weeks, >36 weeks) and birth weight (<1500 g, 1501-2500 g, >2501 g). RESULTS: Corneal curvature measurements decreased progressively with both postconceptual age and birth weight. At <32 weeks, mean (standard deviation) readings were 63.3 (3.2) diopters (D) for the horizontal meridian and 57.3 (2.6) D for the vertical meridian; corresponding values at >36 weeks were 54.0 (3.0) D and 50.7 (2.4) D. In the <1500 g group, mean (SD) readings were 61.3 (3.9) D for the horizontal meridian and 56.0 (2.9) D for the vertical meridian; corresponding values in the >2501 g group were 51.3 (2.1) D and 48.6 (1.8) D. CONCLUSIONS: There is an inverse relation of horizontal and vertical keratometric values with both postconceptional age and birth weight. Highest readings were noted in the babies with the lowest birth weight and youngest postconceptional age. The decrease in corneal dioptric power to normal values is linear and is apparently part of the normal ocular maturation.

Birth Weight↗
PubMed2001

Human embryonic stem cells can differentiate into myocytes with structural and functional properties of cardiomyocytes.

The study of human cardiac tissue development is hampered by the lack of a suitable in vitro model. We describe the phenotypic properties of cardiomyocytes derived from human embryonic stem (ES) cells. Human ES cells were cultivated in suspension and plated to form aggregates termed embryoid bodies (EBs). Spontaneously contracting areas appeared in 8.1% of the EBs. Cells from the spontaneously contracting areas within EBs were stained positively with anti-cardiac myosin heavy chain, anti--alpha-actinin, anti-desmin, anti--cardiac troponin I (anti-cTnI), and anti-ANP antibodies. Electron microscopy revealed varying degrees of myofibrillar organization, consistent with early-stage cardiomyocytes. RT-PCR studies demonstrated the expression of several cardiac-specific genes and transcription factors. Extracellular electrograms were characterized by a sharp component lasting 30 +/- 25 milliseconds, followed by a slow component of 347 +/- 120 milliseconds. Intracellular Ca(2+) transients displayed a sharp rise lasting 130 +/- 27 milliseconds and a relaxation component lasting 200--300 milliseconds. Positive and negative chronotropic effects were induced by application of isoproterenol and carbamylcholine, respectively. In conclusion, the human ES cell--derived cardiomyocytes displayed structural and functional properties of early-stage cardiomyocytes. Establishment of this unique differentiation system may have significant impact on the study of early human cardiac differentiation, functional genomics, pharmacological testing, cell therapy, and tissue engineering.

Actinin↗
PubMed2000

Efficacy of diclofenac versus dexamethasone for treatment after strabismus surgery.

OBJECTIVE: To compare the efficacy of topical diclofenac sodium 0.1% versus dexamethasone 0.1% on the conjunctival healing process and on intraocular pressure (IOP) after strabismus surgery. DESIGN: A randomized clinical trial. PARTICIPANTS: Forty consecutive pediatric patients who underwent strabismus surgery. INTERVENTION: The patients were assigned before surgery to receive topical diclofenac 0.1% (study group, 20 patients) or dexamethasone 0.1% (control group, 20 patients) from immediately after surgery to up to 4 weeks after surgery (both combined with chloramphenicol 0.2%, polymyxin B sulfate 2500 U). MAIN OUTCOME MEASURES: Between-group comparison of five parameters: patient discomfort, conjunctival chemosis, inflammation, gap, and intraocular pressure (IOP) at 1, 2, and 4 weeks after surgery. RESULTS: At postoperative week 2, the diclofenac-treated group showed significantly less patient discomfort and less conjunctival inflammation, edema, and gap than the dexamethasone group (P: = 0.003, P: = 0.04, P: = 0.02, P: = 0. 001, respectively). At week 4, the study patients continued to show less discomfort and conjunctival gap (P: = 0.02). The dexamethasone group showed a significant change in IOP between the preoperative and the fourth postoperative week (P: = 0.001 in the right eye, P: = 0.0005 in the left eye) and an increased prevalence of higher IOP during the fourth postoperative week (P: = 0.01 in the right eye, P: = 0.02 in the left eye). Thirty-eight percent of the dexamethasone group showed an increase in IOP to more than 21 mmHg during the four postoperative weeks. No increase in IOP was noted in the diclofenac group. CONCLUSIONS: Topical diclofenac is superior to dexamethasone for each of the five postoperative parameters examined. Its maximal effect occurred at 2 weeks after surgery, without an increase in IOP or in local subconjunctival hemorrhage.

Adolescent↗
PubMed2000

Diode laser treatment of posterior retinopathy of prematurity.

AIMS: To study the efficacy of infrared diode laser for the treatment of posterior retinopathy of prematurity (ROP). METHODS: 48 eyes of 25 premature babies (mean birth weight 779 (SD 127.7) g; mean gestational age 25.5 (SD 1.47) weeks) with threshold ROP in zone I and posterior zone II were treated by the indirect infrared (810 nm) diode laser. Confluent burns were applied to the avascular retina. In 18 eyes, an additional row of laser burns was added posterior to the ridge. RESULTS: Favourable anatomical results were noted in 41 eyes (85.4%). ROP stage 5 developed in two eyes, ROP stage 4A developed in four eyes, and ROP stage 4B in one eye. Three of the eyes with stage 4A eyes were successfully buckled; the fourth was not operated on and remained demarcated by laser scars. No complications were noted. CONCLUSION: In this series, the diode laser was found to be a safe and effective treatment for posterior ROP.

Female↗
PubMed1999

Slanted lateral rectus recession for exotropia with convergence weakness.

OBJECTIVE: To evaluate the efficacy of slanted recession of the lateral rectus (LR) muscle for exotropia (XT) with convergence weakness. DESIGN: Predesigned, nonrandomized, comparative trial. PARTICIPANTS: Twelve study patients and six control subjects with XT greater at near than at distance by > or =10 prism diopters (PD). INTERVENTION: Twelve consecutive patients underwent slanted LR recession, and six consecutive control subjects underwent standard LR recession. MAIN OUTCOME MEASURES: Between-groups comparison of the postoperative ocular alignment at distance and near, and the difference between them, as well as the stereopsis. RESULTS: Slanted LR recession reduced the XT to <8 PD in all patients at distance and in 11/12 patients at near. Additionally, the mean difference between the distance and near exodeviation was reduced from 14+/-4.5 PD preoperatively to 2.9+/-2.4 PD postoperatively. All patients in the control group demonstrated postoperative deviations of <8 PD at distance, but all had residual exodeviations >8 PD at near. Three of the study patients gained gross stereopsis postoperatively. CONCLUSIONS: Slanted recession of the LR is superior to standard recession in reducing both distance and near XT and in collapsing the difference between them. This technique may also have a positive impact on gross stereopsis.

Accommodation, Ocular↗
PubMed1999

Combined resection and anterior transposition of the inferior oblique muscle for asymmetric double dissociated vertical deviation.

OBJECTIVE: To evaluate the efficacy of combined monocular resection and bilateral anterior transposition of the inferior oblique (IO) muscle for asymmetric double dissociated vertical deviation (DVD). DESIGN: Nonrandomized, comparative clinical trial. PARTICIPANTS: Twelve patients with asymmetric DVD and coexisting unequal IO overaction (IOOA). INTERVENTION: Six consecutive patients underwent combined graded monocular resection and bilateral anterior transposition of the IO muscle and six consecutive historical control patients underwent equal anteriorization of the IO muscle. MAIN OUTCOME MEASURES: Between-group comparison of the postoperative vertical deviation and reduction in IOOA. RESULTS: The mean difference of the asymmetric DVD in the primary position was reduced from 13.3 +/- 4.8 prism diopters (PD) to 2.2 +/- 1.8 PD in the study group (P = 0.001) and from 13.3 +/- 4.0 PD to 10.2 +/- 3.1 PD in the control group (P = 0.003). The difference in improvement between the groups was statistically significant (P = 0.004). The IOOA was significantly reduced in both groups. CONCLUSIONS: Bilateral IO anteriorization with monocular-graded IO resection should be considered as the treatment of choice in patients with asymmetric DVD with IOOA.

Adolescent↗
PubMed1999

Intraocular pressure fluctuations during strabismus operations and the postoperative period.

PURPOSE: To evaluate the intraocular pressure (IOP) variations which occur during and after strabismus surgery. METHOD: We measured the IOP in 34 eyes of 20 pediatric patients undergoing primary strabismus surgery under general anesthesia. Measurements were performed by the Tono-Pen (Mentor O&Q Inc. Norwell, MA) prior to surgery, immediately after suturing of the conjunctive, and 1 week and 4 weeks after surgery. All patients received the same local antibiotics and steroid solutions postoperatively. RESULTS: IOP decreased from baseline to the end of surgery by a mean of 8.26 +/- 1.8 mmHg and increased from baseline to 4 weeks after surgery by a mean of 3.6 +/- 1.8 mmHg. Thirty-eight percent of the eyes had an IOP of 21 mmHg or more during the postoperative period. CONCLUSION: IOP variations are prevalent during and after strabismus surgery. Careful postoperative measurements are recommended in order to identify individuals who may be prone to iatrogenically increased IOP.

Adolescent↗
PubMed1997

Ultrasonography of the optic nerves: clinical application in children with pseudotumor cerebri.

OBJECTIVE: Pseudotumor cerebri (PTC) in children has a wide spectrum of clinical presentations, from headache, which may be posterior and associated with nausea, vomiting or diplopia, to nonspecific headache, which may not be posterior and related or unrelated to other symptoms. In children with nonspecific headache, supportive evidence for diagnosis may be required before invasive procedures such as lumbar punctures are performed. Ultrasonography of the optic nerves (USON) is a noninvasive examination that can provide information about optic nerve changes, including those resulting from increased intracranial pressure. The applicability of USON in the diagnosis and follow-up of PTC was examined. STUDY DESIGN: Seventeen children were referred to our service because of a clinical suspicion of PTC, suggested by the presence of swollen optic nerve discs and/or headache, without clinical evidence of another cause. All had normal brain computed tomography and/or magnetic resonance imaging results before referral. Each child was examined with USON while in the supine position and with a 30-degree head tilt and underwent a lumbar puncture. USON was repeated on follow-up evaluation. RESULTS: The diagnosis of PTC was confirmed by lumbar puncture in 10 children and ruled out in 6 children. Overall, the USON results correlated with an increased opening pressure on lumbar puncture in 11 children. CONCLUSION: We noted an excellent correlation between the clinical results and the USON findings in PTC, and in many cases repeated lumbar punctures could be avoided. USON is more easily applied than a lumbar puncture, without the accompanying risks. It may be used as an indicator of increased intracranial pressure, as well as a follow-up tool. However, further studies are required before the accuracy of USON can be fully established.

Adolescent↗
PubMed1996

Bell's phenomenon in newborns and premature babies.

AIMS: To evaluate the development and course of Bell's phenomenon (BP) in premature and normal neonates. METHODS: Twenty seven preterm infants and 42 healthy full term infants were studied. Mean birth weight, gestational age, and head circumference were recorded. BP was graded from no response to full response. The premature group was examined in the first week of life, and then at 4 and 8 weeks after birth. The full term group was initially examined at the age of 3 days until a full response was observed. RESULTS: No preterm infants exhibited BP during the first week of life, while 8/28 (29.6%) exhibited a weak to full reflex at 8 weeks of age. In the full term group 15/42 neonates (35.7%) demonstrated a mature reflex at age of 3 days and 36/37 (97.3%) at age 16 weeks. A significant correlation was observed between BP, sex, and birth weight, as well as gestational age in the premature group. No such correlation was found in the full term infants. CONCLUSION: BP has a longitudinal course. It is an important clinical marker for evaluation and follow up of neuro-ophthalmic maturation in neonates.

Age Factors↗
PubMed1996

Ultrasonographic findings of the optic disc in congenital glaucoma.

A 2-month-old female infant with intractable congenital glaucoma and diffuse corneal opacification underwent trabeculectomy with 5-fluorouracil (5-FU) injection in both eyes followed by penetrating keratoplasty (PKP) combined with partial cyclocryotherapy in the right eye. The latter procedure was undertaken despite the B-scan ultrasonographic finding of extensive optic disc cupping in order to provide the infant with some degree of improved visual function. The anatomic and functional results are discussed.

Antimetabolites↗