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Biomedical subjects

J Colin

Publications and source records attributed to J Colin.

At least 19 recordsLinked to original sources
PubMed2001

Evidence for spinodal decomposition in nuclear multifragmentation.

Multifragmentation of a "fused system" was observed for central collisions between 32 MeV/nucleon 129Xe and (nat)Sn. Most of the resulting charged products were well identified due to the high performances of the INDRA 4pi array. Experimental higher-order charge correlations for fragments show a weak but nonambiguous enhancement of events with nearly equal-sized fragments. Supported by dynamical calculations in which spinodal decomposition is simulated, this observed enhancement is interpreted as a "fossil" signal of spinodal instabilities in finite nuclear systems.

Journal Article↗
PubMed2001

[Bilateral emphysematous pyelonephritis].

Based on a case report and a review of the literature, the authors describe the features of bilateral emphysematous pyelonephritis. This rare disease with a poor prognosis constitutes a difficult clinical diagnosis. The positive diagnosis is based on urgent computed tomography. The reference treatment is emergency nephrectomy in an intensive care context.

Aged↗
PubMed2001

INTACS inserts for treating keratoconus: one-year results.

OBJECTIVE: To evaluate the use of INTACS micro-thin prescription inserts (Kera Vision, Inc., Fremont, CA) for the treatment of keratoconus. DESIGN: Prospective, nonrandomized (self-controlled) comparative trial. PARTICIPANTS/INTERVENTION: Ten patients from our prospective clinical study who had completed 12 months of follow-up were evaluated. All patients had keratoconus with clear central corneas and were contact lens intolerant. After reviewing corneal pachymetry and topography of individual patients, INTACS inserts of 0.45-mm thickness were placed in the inferior cornea to lift the cone and INTACS of 0.25-mm thickness were inserted superiorly to counterbalance and flatten the overall anterior corneal surface. MAIN OUTCOME MEASURES: Differences between preoperative and postoperative uncorrected visual acuity, best spectacle-corrected visual acuity, manifest refraction, and keratometry values were statistically assessed. Changes in corneal ectasia were evaluated by reviewing corneotopographic maps. RESULTS: No intraoperative complications occurred in this series of patients. Spherical equivalent error and refractive astigmatism were reduced with INTACS inserts treatment. Postoperative month 12 uncorrected visual acuity (logarithm of the minimum angle of resolution [logMAR] mean, 0.35, standard deviation [SD], 0.16 [approximately 20/50, approximately 2 lines]) was significantly better than preoperative (logMAR mean, 1.05; SD, 0.33 [approximately 20/200, approximately 3 lines]; P <or=0.05). Average best spectacle-corrected visual acuity at postoperative month 12 was improved by approximately two lines compared with baseline (logMAR mean, 0.22; SD, 0.12 [approximately 20/32, approximately 1 line]; logMAR mean, 0.38; SD, 0.13 [approximately 20/50, approximately 1 line], respectively). Topographic corneal shape (size and height of the cone) was improved for all subjects after insert placement. CONCLUSIONS: INTACS micro-thin prescription inserts seem to provide a viable method for treating clear corneal keratoconus for patients who are contact lens intolerant. The corneal steepening and astigmatism associated with keratoconus were reduced, and visual acuity was improved with treatment in almost all eyes.

Adult↗
PubMed2001

Ocular surface changes induced by contact lens wear.

PURPOSE: To evaluate subclinical inflammation and mucus production of the conjunctiva in asymptomatic contact lens (CL) wearers, and to obtain an estimation of the chronologic variations in each group. METHODS: Eighteen eyes fitted with rigid CL (RCL) and 28 eyes with soft CL (SCL) worn daily were compared with 10 eyes from five healthy non-CL wearers. Impression cytology (IC) specimens were collected after clinical examination and were analyzed by flow cytometry using antibodies directed to HLA DR and intercellular adhesion molecule type 1 (ICAM-1) (CD 54), as inflammatory markers, and to the peptidic core of the conjunctival mucin (M1/MUC5AC) for mucus and goblet cell detection. The percentage of positive cells was calculated, and levels of fluorescence expression were quantified and compared between each group. RESULTS: A significant increase of HLA DR and ICAM-1 was observed in the SCL group in comparison with the control group. The two inflammatory markers were highly positively correlated with each other. Mucin detection with M1/MUC5AC did not find a significant difference between each group in terms of percentage of positive cells, but analyses of mean levels of fluorescence showed a significant decrease in the two CL groups. Evolution in time was different for each group, with a regular low level of inflammation in the RCL group in the first 10 years in comparison with the SCL group. In the SCL group, inflammation seemed to be higher before 2 years and after 10 years of wear. Mucin expression was variable in time, but without significant difference at any time. CONCLUSION: This study confirms difference in expression of subclinical conjunctival inflammation in asymptomatic CL wearers, with lower levels for RCL than SCL wearers with daily or extended wear. The mucin system is also modified by this low but chronic aggression of the ocular surface, with a tendency to decrease with time in the RCL and SCL groups.

Adult↗
PubMed2001

[Potential association of pseudoexfoliation syndrome (PEX) with age-related macular degeneration (ARMD)].

PURPOSE: Authors report an unexpected association between PEX and ARMD. It was an additional result of a study, that analysed possible systemic symptoms of pseudoexfoliation material in visceral organs. They reviewed literature data for both, concerning epidemiology and physiopathogeny. MATERIAL AND METHODS: We conducted an age-and sex matched study of 142 patients in Brittany, 71 PEX and 71 controls, 31 men and 40 women in the 2 groups. The statistical study was performed with Epi Info 6.0 software using the X2 of Mantel-Haenszel Test. RESULTS: Statistical positive relation was found between PEX and ARMD (p=0.02), both increasing with age. DISCUSSION AND CONCLUSION: Part of epidemiology seems to be similar in PEX and ARMD, especially environment role (particularly solar radiations), individual factors, and genetic predisposition. For the first time, in may 1999, a genetic localization of PEX was discovered on the chromosome II, and nearly of one loci of ARMD multiple localizations.

Age Distribution↗
PubMed2001

[Motivation of candidates for refractive surgery].

PURPOSE: To determine the profile and motivations of patients who are candidates for refractive surgery. MATERIAL: and METHODS: We studied 102 patients with low myopia (less than 6 diopters) in a single-center investigation. RESULTS: Among the total population studied, the motivation for refractive surgery was essentially comfort and appearance. Fewer men wore contact lenses than women and had worn them for a shorter period of time. Those involved in sports were more often in individual sports. Contact-lens wearers were most often students or in the paramedical professions. DISCUSSION: The population interested in refractive surgery was very young. The proportion of candidates who had never worn contact lenses was surprisingly high. CONCLUSION: This analysis suggests that patients too often consider refractive surgery as an easy option.

Adolescent↗
PubMed2001

[Excimer surface photoablation versus Lasik for correction of mild myopia].

INTRODUCTION: Above -6 diopters, Lasik procedure has shown its superiority in term of predictibility, efficacy and stability. In the adverse, in the field of low myopia, Lasik and surface excimer photoablation (PRK) are very controversial. We compare quantitative and qualitative outcome achieved in series of 25 PRK operated patients and 25 Lasik. MATERIAL AND METHOD: 2 homogeneous groups were constituted: group A for Excimer patients and group B for Lasik. Initial ametropia had to be ranged between -2 and -6 diopters (D), eventually associated to a myopic astigmatism that needed to be under -1,75 D. Excimer laser model was a Visx (Visx 20/20 or Star S2). In case of Lasik, flap was performed with an Automated corneal shaper microkératom (Baush & Lomb) or with a Flap Maker (Ioltech). Evaluation of refraction and visual results was associated to measurements of contrast and glare sensitivities and collection of functional complaints. RESULTS: A retrospective analysis is performed with a 2 years follow-up. At that term, rate of eyes, that achieved 20/20 or better is comparable in the two groups (62% in group A and 64% in group B). However, profile of visual recovery goes faster after Lasik. Best corrected visual acuity is favorably preserved in two groups, but is altered with glare in Lasik group. Cycloplegic refraction shows a tendency to regression more important in case of surface ablation (10% versus 4%), especially above -4 D (28%). No significant difference is noted concerning contrast sensitivity, correctly unchanged in the two groups. No case of severe complication is mentioned after both surgical methods. DISCUSSION-CONCLUSION: In the field of low myopia, PRK and Lasik appear to guarantee same predictibility and safety, in conditions of preliminary learning curve. Stability and visual recovery are earlier achieved after Lasik, in addition to postoperative indolence. However, application of this technique to all degrees of myopia requires its perfect control and an adjustment of ablation nomograms.

Adult↗
PubMed2001

[Pharmacologic stimulation of ejaculation with midodrine hydrochloride (Gutron) for medically assisted reproduction in spinal injury].

INTRODUCTION: Midodrine hydrochloride (Gutron) is proposed to induce ejaculation in spinal injury patients desiring paternity as an alternative to vibromassage, electrostimulated ejaculation and surgical collection of spermatozoa. The authors report their experience in 10 spinal injury patients. PATIENTS AND METHODS: 14 trials of pharmacologically-induced ejaculation were performed in a context of medically assisted reproduction (MAR) in 10 spinal injury patients (7 with paraplegia > T11; 1 with paraplegia < or = T11; 2 with quadriplegia) an average of 4.5 years after the injury. Patients had a mean age of 28.5 years (range: 18 to 36 years). Nine had persistent reflex erections. After IC injection of prostglandin E, 10 to 30 mg of Gutron was administered by slow i.v. infusion. Spermatozoa were collected during antegrade ejaculation and/or in previously alkalinised urine. RESULT: Ejaculation was obtained in 10 cases (71.4%), either antegrade (7 cases), or retrograde (3 cases). The 4 failures corresponded to ejaculation failure in 3 cases and adverse effects of Gutron (hypertension) in 1 case. However, storage of spermatozoa could be performed in only 4 cases (40%), as pyospermia or severe necrospermia were observed in 6 cases. CONCLUSIONS: Midodrine hydrochloride gives good results in terms of ejaculation in spinal injury patients. However, the quality of semen collected is often poor due to the long interval since the initial trauma. Midodrine hydrochloride, ideally used after antibiotic treatment, can nevertheless constitute an alternative to other techniques.

Adolescent↗
PubMed2000

Comparison of the efficacy and safety of valaciclovir and acyclovir for the treatment of herpes zoster ophthalmicus.

OBJECTIVE: To compare the efficacy and safety of valaciclovir and acyclovir in immunocompetent patients with herpes zoster ophthalmicus. DESIGN: A multicenter, randomized, double-masked study. PARTICIPANTS: One hundred ten immunocompetent patients with herpes zoster ophthalmicus diagnosed within 72 hours of skin eruption were treated; 56 were allocated to the valaciclovir group and 54 to the acyclovir group. METHODS: Patients randomized to the valaciclovir group received two 500-mg tablets of valaciclovir three times daily and one tablet of placebo twice daily. Patients in the acyclovir group received one 800-mg tablet of acyclovir five times daily and one tablet of placebo three times daily for 7 days. MAIN OUTCOME MEASURES: Main outcome measures included the frequency, severity, and duration of ocular complications, patient reports of zoster-associated pain, and the outcome of skin lesions. Tolerance was also assessed on the incidence and types of adverse effects and changes in laboratory parameters. The analysis was mainly descriptive and performed on an intent-to-treat basis. RESULTS: Ocular complications of herpes zoster ophthalmicus were similar in the valaciclovir and acyclovir treatment groups. The main complications were conjunctivitis (54% and 52%, respectively), superficial keratitis (39% and 48%, respectively for punctate keratitis; 11% in each group for dendritic keratitis), stromal keratitis (13% in each group), and uveitis (13% and 17%, respectively). The long-term outcomes of these ocular complications were favorable and similar in both treatment groups. Pain duration and severity and outcome of skin lesions were similar between groups. Most patients reported prodromal pain. After 1 month, 25% of patients in the valaciclovir group and 31% in the acyclovir group still reported pain. The percentage of patients experiencing postherpetic neuralgia decreased during follow-up. The tolerance to acyclovir and valaciclovir was comparable and considered good. The most frequent adverse events were vomiting and edema of the eyelids or face (3%-5%). Three serious adverse events not linked to the study drugs occurred. CONCLUSIONS: Valaciclovir is as effective as acyclovir in preventing ocular complications of herpes zoster ophthalmicus, including conjunctivitis, superficial and stromal keratitis, and pain. Tolerability of the two drugs is similar, but the dosing schedule of valaciclovir is simpler.

Acyclovir↗
PubMed2000

Correcting keratoconus with intracorneal rings.

PURPOSE: To evaluate the potential of intrastromal corneal ring technology (Intacs, KeraVision) to correct keratoconus without central corneal scarring. SETTING: Department of Ophthalmology, Brest University Hospital, Brest, France. METHODS: In this prospective, noncomparative, interventional case series, Intacs segments were implanted in 10 keratoconic eyes with clear central corneas and contact lens intolerance after corneal pachymetry was checked. Segment thicknesses varied based on corneal topography analysis. RESULTS: No intraoperative complications occurred. The mean follow-up was 10.6 months. Postoperative results revealed a reduction in astigmatism and spherical correction and an increase in topographical regularity and increased uncorrected visual acuity. CONCLUSION: Intacs technology can reduce the corneal steepening and astigmatism associated with keratoconus.

Adult↗
PubMed2000

Effect of intrastromal corneal ring segment shift on clinical outcome: one year results for low myopia.

PURPOSE: To evaluate the effect of intrastromal corneal ring segment (ICRS) shift on clinical outcome. SETTING: Chu Morvan Ophthalmology Service, Brest, France. METHODS: Forty-seven eyes with myopia from -1.0 to -5.0 diopters (D) had ICRS surgery according to United States Food and Drug Administration protocol using a 2-segment implant design. Visual acuity, refractive, videotopographic, and biomicroscopic results in eyes that did not have contact between segments (Group A, n = 26) and in eyes that did have contact (Group B, n = 21) were compared. RESULTS: Soon after surgery, migration of and subsequent contact between the implant segments occurred in 21 eyes (45%). Contact between the inferior ends was most common, occurring in 19 eyes; in the remaining 2 eyes, the superior ends of the implant touched. Superior contact was associated with superficial channels, wound-healing problems, and ICRS explantation. No segment shift was observed after the first postoperative week. No significant differences in visual acuity, qualitative vision, or density of intrastromal deposits were noted between the 2 groups. However, at 6 months there was more induced with-the-rule cylinder in Group B (mean +1.3 D +/- 0.7 [SD]) than in Group A (mean +0.7 +/- 0.5 D). Astigmatism was clinically significant in only 3 cases at 3 months. CONCLUSIONS: Induced cylinder remains a limitation of the ICRS procedure, and segment contact appears to influence the rate of induced cylinder. Overall, however, the ICRS procedure produces promising results. Research efforts are underway to address induced cylinder and channel deposits associated with ICRS surgery.

Adult↗
PubMed2000

Levels of collagen degradation products (telopeptides) in the tear film of patients with keratoconus.

PURPOSE: Levels of collagen degradation products (telopeptides) in the tear film of patients with keratoconus were measured to study the release of telopeptides in the tears. METHODS: Tear samples were collected from 26 keratoconus patients and 36 age-similar human control subjects. Levels of telopeptides were quantified and compared between the two groups. RESULTS: The telopeptide level in tears from keratoconus patients was 2.5-fold higher than in tears from the control group. The telopeptide concentration was age-dependent in both groups. In tears from young people, telopeptide level was 2-fold higher than in tears from the older people. CONCLUSION: The tear film of patients with keratoconus contains higher levels of telopeptides than those of control subjects. Determination of telopeptide levels in tears could be useful for the follow-up of keratoconus development in patients.

Adolescent↗
PubMed2000

A strategy for vascular services--testing the 600,000 population model.

BACKGROUND: Vascular services' delivery has been criticised, and re-organisation based on a 600,000 population model suggested. We assessed the feasibility of this model in three geographically disparate English regions. METHODS: Surgical arterial activity by Trust was analyzed using 1994/95 data from Hospital Episode Statistics. A postal survey of acute Trusts was used to assess vascular facilities and personnel. Distances between hospitals and enumeration districts were mapped using a Geographical Information System. MAIN OUTCOME MEASURES: Number (proportion) of Trusts performing over 100 arterial procedures a year. Number (proportion) of Trusts with a vascular on-call rota. Proportion of population likely to live more than 40 km away (equivalent to 1 h blue-light ambulance travel time) from a vascular unit under the proposed model. RESULTS: Twelve of the 32 Trusts (38%) performed over 100 arterial procedures annually; 23 Trusts completed the survey. Of these, five (22%) had a vascular on-call rota. Under the 600,000 model, in East Anglia a further 16.5% of the population would live > 40 km from a vascular unit. In Wessex, a further 0.4% of the population would live > 40 km from a vascular unit. Impact on access in North West Thames was negligible. CONCLUSIONS: A 600,000 population model could be feasible in urbanized regions, but not in geographically remote ones.

Delivery of Health Care↗
PubMed2000

[Indomethacin (indocollyre) versus diclofenac (voltarene) for the control of pain following excimer photoablation].

PURPOSE: To compare effect of two topical non steroidal anti-inflammatory (NSAI) drugs: Indomethacin (Indocollyre)0.1 %, Chauvin Inc.) and Diclofenac (Voltaren 0.1%, Cibavision) on postoperative pain and epithelial regrowth following surface excimer photoablation. MATERIAL AND METHOD: Eighty-six excimer operated patients, were divided in two similar groups depending on the NSAI instilled postoperatively and for 3 days (4 drops daily). No patient was informed of any other available drug. Pain intensity was quantified between 1 and 10 according to an analog scale (reported from 1 to 10 hours, then 4 times a day during 7 days). Complementary medications and functional symptoms were also notified. Biomicroscopic evaluation using fluorescein test was performed to assess reepithelialization. RESULTS: In term of pain, no significative difference was observed between the two groups concerning intensity, associated medications, or numbers of days of discomfort. Controversially, retreated eyes might induce more pain than initial treatments. No delay in epithelial regrowth was noted and the difference between the two groups in functional complaints was no statistically significant. Pain appears to be not related to ablation depth. DISCUSSION- CONCLUSION: Our results are correlated to literature reported data. Introduction of NSAI constitutes a real advent in the care of excimer postoperative pain. Effect of indomethacin seems comparable to diclofenac effect, but might be of interest because of no anesthetic property that might guarantee of no delay in wound healing response.

Adult↗
PubMed2000

[Excimer photorefractive keratectomy (PRK) versus intrastromal corneal ring segments (ICRS) for correction of low myopia].

PURPOSE: Theoretical differences between ablative and additive surgeries are obvious, but what about final outcome? We decide to compare surface excimer photorefractive ablation (PRK) with Intracorneal segments (Intacs or ICRS) for correction of low myopia. MATERIAL: and METHOD: Two homogeneous groups of 25 low pure myopic patients were considered: group A including patients operated with Excimer and group B corresponding to Intacs implanted eyes. Retrospective analysis was performed and compared data achieved at two years follow-up, in term of refractive results and qualitative vision. RESULTS: Considering non corrected visual acuity, percentages of eyes who achieved 20/40 or better are comparable in the two series (respectively 97% in group A and 99% in group B). In the adverse, proportion of patients achieving 20/20 or more is superior in Intacs group (77%) versus 62% in PRK group. In all cases, quality of vision is altered in early postoperative period, then returns to normal between 1 and 3 months. Functional complaints appear more frequent and persisting in intrastromal segments group. Based on videotopography and cycloplegic refraction, it seems that risk of induced astigmatism occurrence is significantly increased in case of Intacs. No severe complication is mentioned in both groups. DISCUSSION CONCLUSION: Final outcome are in favor of the efficacy, safety and predictability of the two methods for correction of low myopia. Concept of Intacs presents the interest of potential adjustability and respect of central corneal area; however it appears to be limited by the occurrence of an induced astigmatism.

Adult↗