PubMed Health⌕ Search

Biomedical subjects

A Gilbert

Publications and source records attributed to A Gilbert.

At least 19 recordsLinked to original sources
PubMed2006

Review of solutions for 3D hydrodynamic modeling applied to aquaculture in South Pacific atoll lagoons.

A workshop organized in French Polynesia in November 2004 allowed reviewing the current methods to model the three-dimensional hydrodynamic circulation in semi-enclosed atoll lagoons for aquaculture applications. Mollusk (e.g. pearl oyster, clam) aquaculture is a major source of income for South Pacific countries such as French Polynesia or Cook Islands. This aquaculture now requires a better understanding of circulation patterns to improve the spatial use of the lagoons, especially to define the best area to set larvae collectors. The pelagic larval duration of the relevant species (<20 days) and the size of the semi-closed lagoons (few hundreds of km2) drive the specifications of the model in terms of the spatial and temporal scale. It is considered that, in contrast with fish, mollusk larvae movements are limited and that their cycle occurs completely in the lagoon, without an oceanic stage. Atolls where aquaculture is productive are generally well-bounded, or semi-closed, without significant large and deep openings to the ocean. Nevertheless part of the lagoon circulation is driven by oceanic water inputs through the rim, ocean swells, tides and winds. Therefore, boundary conditions of the lagoon system are defined by the spatial structure of a very shallow rim (exposition and number of hoas), the deep ocean swell climate, tides and wind regimes. To obtain a realistic 3D numerical model of lagoon circulation with adequate forcing, it is thus necessary to connect in an interdisciplinary way a variety of methods (models, remote sensing and in situ data collection) to accurately represent the different components of the lagoon system and its specific boundary conditions. We review here the current methods and tools used to address these different components for a hypothetical atoll of the Tuamotu Archipelago (French Polynesia), representative of the semi-closed lagoons of the South Pacific Ocean. We hope this paper will serve as a guide for similar studies elsewhere and we provide guidelines in terms of costs for all the different stages involved.

Animals↗
PubMed2006

Cost-effectiveness of pharmacotherapies for nicotine dependence in primary care settings: a multinational comparison.

OBJECTIVE: To estimate the incremental cost-effectiveness of the first-line pharmacotherapies (nicotine gum, patch, spray, inhaler, and bupropion) for smoking cessation across six Western countries-Canada, France, Spain, Switzerland, the United States, and the United Kingdom. DESIGN AND STUDY POPULATION: A Markov-chain cohort model to simulate two cohorts of smokers: (1) a reference cohort given brief cessation counselling by a general practitioner (GP); (2) a treatment cohort given counselling plus pharmacotherapy. Effectiveness expressed as odds ratios for quitting associated with pharmacotherapies. Costs based on the additional physician time required and retail prices of the medications. INTERVENTIONS: Addition of each first-line pharmacotherapy to GP cessation counselling. MAIN OUTCOME MEASURES: Cost per life-year saved associated with pharmacotherapies. RESULTS: The cost per life-year saved for counselling only ranged from US190 dollars in Spain to 773 dollars in the UK for men, and from 288 dollars in Spain to 1168 dollars in the UK for women. The incremental cost per life-year saved for gum ranged from 2230 dollars for men in Spain to 7643 dollars for women in the US; for patch from 1758 dollars for men in Spain to 5131 dollars for women in the UK; for spray from 1935 dollars for men in Spain to 7969 dollars for women in the US; for inhaler from 3480 dollars for men in Switzerland to 8700 dollars for women in France; and for bupropion from 792 dollars for men in Canada to 2922 dollars for women in the US. In sensitivity analysis, changes in discount rate, treatment effectiveness, and natural quit rate had the strongest influences on cost-effectiveness. CONCLUSIONS: The cost-effectiveness of the pharmacotherapies varied significantly across the six study countries, however, in each case, the results would be considered favourable as compared to other common preventive pharmacotherapies.

Adult↗
PubMed2004

Long-term results on abduction and external rotation of the shoulder after latissimus dorsi transfer for sequelae of obstetric palsy.

Transfer of the latissimus dorsi to the rotator cuff is widely used for restoring shoulder abduction and external rotation in sequelae of brachial plexus palsy; however, its long-term results are not well known. Because persistence of clinical benefits is crucial for children with brachial plexus palsy, the aim of our study was to evaluate retrospectively the long-term results of this transfer in 203 children. Patients were classified according to type of paralysis (C5-C6, C5-C6-C7, and complete), degree of preoperative shoulder function according to Gilbert, and age at surgery. Active abduction and external rotation were measured at 1, 3, 6, 10, and 15 years and the results were analyzed statistically. Children with sequelae of C5-C6 palsy gained in abduction and external rotation more than children with C5-C6-C7 or complete palsy. Patients with mild preoperative shoulder dysfunction achieved the best results. The data showed the clinical results were related to the type of paralysis and to preoperative shoulder function, but not to age at surgery. They also showed progressive deterioration of abduction began at 6 years despite preserved active external rotation.

Adolescent↗
PubMed2003

Duration judgements in patients with schizophrenia.

BACKGROUND: The ability to encode time cues underlies many cognitive processes. In the light of schizophrenic patients' compromised cognitive abilities in a variety of domains, it is noteworthy that there are numerous reports of these patients displaying impaired timing abilities. However, the timing intervals that patients have been evaluated on in prior studies vary considerably in magnitude (e.g. 1 s, 1 min, 1 h etc.). METHOD: In order to obviate differences in abilities in chronometric counting and place minimal demands on cognitive processing, we chose tasks that involve making judgements about brief durations of time (< 1 s). RESULTS: On a temporal generalization task, patients were less accurate than controls at recognizing a standard duration. The performance of patients was also significantly different from controls on a temporal bisection task, in which participants categorized durations as short or long. Although time estimation may be closely intertwined with working memory, patients' working memory as measured by the digit span task did not correlate significantly with their performance on the duration judgement tasks. Moreover, lowered intelligence scores could not completely account for the findings. CONCLUSIONS: We take these results to suggest that patients with schizophrenia are less accurate at estimating brief time periods. These deficits may reflect dysfunction of biopsychological timing processes.

Adolescent↗
PubMed2002

Purification of human immunoglobulin G: a new approach to plasma fractionation.

BACKGROUND AND OBJECTIVES: Currently, plasma fractionation involves multiple processing steps using established methods such as ethanol precipitation and column chromatography. The known limitations associated with conventional purification techniques, combined with strict regulations on safety and high demand for particular plasma proteins, have resulted in a shortage of plasma-derived therapeutics such as intravenous immunoglobulin G (IgG). MATERIALS AND METHODS: In this study, IgG was purified from human plasma using Gradiflow technology, an electrophoresis-based separation technology. RESULTS: IgG was isolated from plasma to high purity, with 94 +/- 5% recovery in a short processing time. CONCLUSIONS: The technology has been shown to be linearly scalable and has the capacity to contribute to increased production of important plasma fraction therapeutics.

Chemical Fractionation↗
PubMed2002

Surgical correction of supination deformity in children with obstetric brachial plexus palsy.

We present a series of 40 children who were operated on for supination contracture following severe obstetric brachial plexus palsy. Surgery was done at an average age of 7 years and the mean postoperative follow-up was 4 years. In the 23 cases treated by an open or closed radial osteotomy, the mean intraoperative derotation was 78 degrees, the immediate postoperative position was 29 degrees pronation and it stabilized at follow-up at 17 degrees pronation. Biceps rerouting was performed in 17 cases without any recurrence of supination deformity and the final position was 22 degrees pronation. Some active forearm rotation was obtained in a few cases. These surgical corrections are part of an overall treatment plan and allow the "begging hand" to be corrected to a more functional and less noticeable position.

Adolescent↗
PubMed2001

Surgical anatomy of spinal accessory nerve: is trapezius functional deficit inevitable after division of the nerve?

The course of spinal accessory nerve in the posterior triangle, the innervation of the sternocleidomastoid and trapezius muscles and the contributions from the cervical plexus were studied in 20 cadaveric dissections. The nerve was most vulnerable to iatrogenic injuries after leaving the sternocleidomastoid. Direct innervation of trapezius by cervical plexus branches was noted in five dissections, whereas connections between the cervical plexus and the spinal accessory nerve were observed in 19 dissections. These were usually under the sternocleidomastoid (proximal to the level of division of the nerve in nerve transfer procedures). Although the contribution from the cervical plexus to trapezius innervation is considered minimal, trapezius function can be protected in neurotization procedures by transecting the spinal accessory nerve distal to its branches to the upper position of trapezius.

Accessory Nerve↗
PubMed2001

The posterior interosseous reverse flap: experience with 113 flaps.

The authors have used a posterior interosseous flap for resurfacing in 113 cases of hand injury during the past 13 years. Its main indications were complex hand trauma or burn injuries with large skin loss, either acute or postprimary. Flaps survived completely in 98 patients. Twelve patients had superficial necrosis of the distal part of the flap, which did not require additional surgical procedures. Three flaps were lost and alternative coverage was used. Six patients demonstrated paralysis of the motor branch to the extensor muscles of the wrist or fingers (generally to the extensor carpi ulnaris, the extensor digiti quinti, or the extensor pollicis longus). All recovered completely within 6 months. The donor area was closed directly in 3 to 4-cm-wide flaps, leaving an inconspicuous scar. Larger flaps required skin grafting. Donor site morbidity was minimal. Major anatomic variations precluding the use of the flap were encountered twice in this series.

Adolescent↗
PubMed2001

Long-term results of free vascularized fibular grafting for femoral head necrosis.

The current authors report on the long-term results of free vascularized fibula transplantation for the treatment of idiopathic femoral head necrosis. Briefly, the technique introduced by the authors in 1978 involves the excision of the necrosed bone and its replacement by autologous cancellous bone taken from the iliac crest. The contralateral fibula with its nutrient vessels is introduced through the head and neck of the femur and the vessels are anastomosed microsurgically to the anterior circumflex artery and vein. The current study assesses 60 patients (68 hips) operated on from 1978 to 1985 with an average followup of 18 years (range, 15-22 years). The overall results were good in 52% of the patients. In relation to the stage of necrosis according to the classification system of Marcus et al, good results were achieved in 80% of the patients with Stages II and III disease. In relation to patient age, good results were obtained in 80% of the patients operated on before the age of 40 years. The long-term results indicate that the method of free vascularized fibula transplantation used by the authors is a valuable method for the treatment of idiopathic osteonecrosis of the femoral head for patients younger than 40 years of age with Stage II or III necrosis.

Adult↗
PubMed2001

A randomised trial of oral versus vaginal administration of misoprostol for the purpose of mid-trimester termination of pregnancy.

A prospective randomised controlled trial was undertaken to compare the efficacy of two routes of administration, oral versus vaginal, of the prostaglandin E1 analogue misoprostol (Cytotec) to effect termination of pregnancy in the mid-trimester. Fifty-five women were recruited into the trial; 26 to receive all doses orally and 29 via the vaginal route. The dosing regimen was 400 microg as the initial dose followed by a second dose of 200 microg two hours later and then four-hourly 200 microg doses until delivery or 32 hours from commencement of treatment. If delivery had not been effected by the last dose of misoprostol, a Syntocinon infusion was started synchronously Misoprostol administered vaginally was significantly more effective than when administered orally as judged by induction-to-delivery interval and also the need or otherwise to augment therapy with a Syntocinon infusion. The average induction-to-delivery interval was 17.5 hours in the vaginal group compared to 33 hours in the oral group (p = 0.0003). The percentages of women who delivered at 24 and 48 hours were 93% and 100% in the vaginal administration group and 19% and 70% in the oral administration group (p < 0.05). No significant differences in complication rates or side effects were noted between the two groups

Abortifacient Agents↗
PubMed2001

Purification of fibrinogen and virus removal using preparative electrophoresis.

The Gradiflow is a novel, scalable preparative electrophoresis technique that uses the dual characteristics of size and charge to isolate target macro- and micromolecules from complex biological solutions. It does this with high resolution and in rapid time. The mild buffers are used to assist in retaining biological activity of the isolated protein. Gradiflow technology employs a sandwich of three polyacrylamide membranes configured to allow passage of macromolecules ranging in size from 10 kDa to 1,500 kDa. Fibrinogen was isolated from cryoprecipitate 1 using a single phase process. This separation was achieved within three hours with yields of 85%. Purified fibrinogen was then characterized using biophysical characterization of fibrin clot structure and compared with clots derived from a commercially available product and human plasma. Significantly, clots developed from Gradiflow fibrinogen had characteristics closer to human plasma. Viral removal characteristics of the Gradiflow were investigated by spiking the source material (cryoprecipitate 1) with canine parvovirus and testing for its presence in the isolated fibrinogen using PCR. Parvo removal was found to be greater than 4 logs and was achieved during the purification process. The Gradiflow offers the advantage of large-scale separation of macromolecules and provides a new approach to fibrinogen separation that is quite distinct from other present-day technologies. The technology is capable of isolating protein with high purity, recovery, and functionality in combination with the removal of viruses during the purification. Furthermore, it is capable of integrating into present production systems, significantly improving yield and functionality of target molecules.

Base Sequence↗
PubMed2001

Vascularization of the thumb. Anatomy and surgical applications.

Microsurgical procedures require rapid and atraumatic dissection of vessels. The authors have tried to schematize the most common variations of the palmar arteries, dividing the thumb into three segments, delimited from the MCP and interphalangeal flexion crease. If a vascular anastomosis has to be carried out in the first segment, the arteries that intersect the palmar surface of such a region do not generally hold much interest for the surgeon as far as size and constancy are concerned. One therefore can avoid frustration while searching in vain for such an artery by starting dissection in the dorsal compartment, where there is a much better chance of finding an artery suitable in every aspect. In replanting a thumb in the second segment, the ulnar collateral artery should be the artery that is looked for first, because it is usually the biggest, the most superficial, and nearly always is composed of a single trunk (Fig. [figure: see text] 18). Let us not forget, however, that the contralateral artery can frequently have all the necessary requirements for an adequate anastomosis. In the third segment, the layout of the vessels is rather difficult to schematize; if it is true that the inverted Y or H shape can make a microanastomosis easier in cases of distal reimplantation (Fig. 19), it is also true that such a pattern is impossible to foresee, and, therefore, the interest of such classification is more academic than practical. Skin loss coverage at the thumb level greatly differs from the that of fingers. In the past few years, a multitude of useful new flaps has been presented by different authors. Their accomplishment (especially those of the last generation, who base their survival on extremely fine vascular axes) presupposes an adequate knowledge of surgical and microsurgical anatomy. Surgeons dealing with this type of pathology should be capable of performing all of the possible flaps because each may be indicated in specific situations.

Arteries↗
PubMed2000

The photodimerisation of trans-cinnamic acid and its derivatives: a study by vibrational microspectroscopy.

Infrared and Raman spectroscopies have been used to monitor the [2 + 2] photodimerisation reactions of alpha-trans-cinnamic acid and of a number of its derivatives. The principal changes observed in the spectra upon dimerisation are decay of a band around 1637 cm(-1), which is assigned to v(C=C) of the ethene bond of the monomer, and growth of bands just above 3000 cm(-1), which result from v(C-H) of saturated carbon atoms of the dimer. The use of microscope attachments has allowed us to follow the reactions of single crystals and we conclude that the reactions are topotactic in nature. We have carried out preliminary kinetic experiments in which spectra of one single crystal are recorded after sequential periods of photolysis. We find that the rates of dimerisation of differently substituted cinnamic acids are similar, with physical effects, such as the thickness of an individual crystal, outweighing any observed electronic effects (inductive or mesomeric).

Cinnamates↗
PubMed2000

Thalamic volume in pediatric obsessive-compulsive disorder patients before and after cognitive behavioral therapy.

BACKGROUND: Neurobiologic abnormalities in the thalamus have been implicated in the pathophysiology of obsessive-compulsive disorder. We recently reported increased thalamic volume in treatment-naive pediatric obsessive-compulsive disorder patients versus case-matched healthy comparison subjects that decreased to levels comparable to control subjects after effective paroxetine therapy. To our knowledge, no prior study has measured neuroanatomic changes in the thalamus of obsessive-compulsive disorder patients near illness onset before and after cognitive behavioral therapy. METHODS: Volumetric magnetic resonance imaging studies were conducted in 11 psychotropic drug-naive 8-17-year-old children with obsessive-compulsive disorder before and after 12 weeks of effective cognitive behavioral therapy monotherapy (> or =30% reduction in obsessive-compulsive disorder symptom severity). RESULTS: No significant change in thalamic volume was observed in obsessive-compulsive disorder patients before and after cognitive behavioral therapy. CONCLUSIONS: Our findings suggest that reduction in thalamic volume after paroxetine therapy may be specific to paroxetine treatment and not the result of a general treatment response or spontaneous improvement. These results are preliminary in view of the small sample studied.

Adolescent↗
PubMed2000

The extended latissimus dorsi muscle island flap for flexion or extension of the fingers.

We describe the technique of transferring the latissmus dorsi muscle as an island flap for the restoration of digital flexion or extension in 28 patients. The latissmus dorsi muscle is raised down to the posterior iliac crest and prolonged with the gluteal superficial facia. We believe that this method is particularly suitable for extensive and prolonged paralysis of the lower elements of brachial plexus. It can be used also for severe Volkmann's contracture or the loss of flexor or extensor muscles of the fingers due to extensive debridement. The technique does not require microsurgery and there is no delay in reinnervation of the muscle.

Adolescent↗
PubMed2000

[Vascularized bone grafts in children. Specifics and indications].

The authors report on the vascularized bone grafts used in children. Some of them are the same as those used in adults, like the fibula free flap. Others are growth plate transfers as the proximal fibular epiphysis, the iliac crest or the lateral scapular crest. Finally, other transfers are periosteal vascularized grafts. The indications and results are discussed concerning the congenital pseudarthrosis of the tibia (43 cases treated by the first author), the congenital pseudarthrosis of the forearm, the tumors of the limb and the post-traumatic defects. The specific indications in children are the microsurgical growth plate transfers, especially the epiphyseal growth fibula for the upper limb and the iliac crest for the lower limb.

Bone Transplantation↗
PubMed2000

Coverage of large skin defects of the pediatric upper extremity.

Reconstructive surgery of the locomotion apparatus in children has been built from several surgical advances. It is a specific activity that cannot be detached from all other orthopedic pediatric surgery. The care of problems in a child must be provided with a holistic point of view: It cannot be the addition of different techniques done by different surgeons. Bone morphology has a close relationship with the soft tissues; an injury of the envelope has consequences for growth harmony.

Arm Injuries↗