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Biomedical subjects

M Roland

Publications and source records attributed to M Roland.

At least 91 records · Page 5Linked to original sources
PubMed1990

Tissue distribution of doxorubicin associated with polyisohexylcyanoacrylate nanoparticles.

The body distribution of i.v. doxorubicin depends mainly on the physicochemical characteristics of the molecule. However, entrapment of that cytostatic drug inside polyalkylcyanoacrylate nanoparticles has been shown to modify its distribution profoundly in the mouse. Polysiohexylcyanoacrylate nanoparticles loaded with [14C]-doxorubicin were studied in comparison with free drug, with emphasis on their distribution pattern in mouse tissue after i.v. administration. An autoradiographic study showed that most of the radioactivity was found in the reticuloendothelial system as soon as a few minutes after i.v. administration of the doxorubicin-loaded nanoparticles. Quantitative determinations by liquid scintillation counting in fresh tissue (spleen, heart, kidneys, liver, lungs, bone marrow) and blood samples confirmed these observations. When the drug was linked to nanoparticles, doxorubicin blood clearance was reduced during the first few minutes after administration, whereas heart and kidney concentrations were substantially decreased. Assays of doxorubicin and doxorubicinol by a specific HPLC analytical method gave results very similar to those obtained by scintillation counting.

Animals↗
PubMed1990

Antimicrobial prophylaxis in elective colorectal surgery and appendicitis.

The purpose of this presentation is to evaluate the role of anaerobic and aerobic microorganisms in postoperative infections after colorectal surgery and appendicitis, and to evaluate when antimicrobial agents should be administered prophylactically in conjunction with these operations. In one multicenter study, prophylactic regimens against anaerobic and aerobic microorganisms were compared for durations of one and three days after colorectal surgery. In another multicenter study, the effect of a regimen against anaerobes used alone or in combination with an agent against aerobes in one preoperative dose were compared. The different types of operations had different potential for postoperative infections. An antimicrobial agent against anaerobic microorganisms given as one preoperative dose may suffice in surgery on the upper part of the colon, but a combination with an agent against aerobic bacteria is recommended in rectal surgery. The effectiveness of agents against anaerobic and aerobic bacteria in preventing postoperative infections after appendectomy in cases of gangrenous or perforated appendicitis without general peritonitis were compared in another study. This concluded that an agent against anaerobes is recommended when the appendix is gangrenous or perforated.

Anti-Bacterial Agents↗
PubMed1989

Randomized controlled trial of an educational booklet for patients presenting with back pain in general practice.

A randomized controlled trial was used to evaluate an educational booklet on back pain for patients presenting to five group practices during one calendar year. The booklet had no immediate effect on consultations for back pain, but in the period from two weeks to one year after presentation significantly fewer patients in the group receiving the booklet consulted with back pain (35.6%) than in the control group (42.2%) (P less than 0.05). There were no significant differences between the booklet and control groups in certified absence from work owing to back pain. Referral to hospital, referral to physiotherapy, admissions to hospital and laminectomies were all less common in the booklet group. The reduction in the combined referral rate to physiotherapy and hospital, and the reduction in laminectomy rate almost reached statistical significance at the 5% level. In replying to a questionnaire sent one year after entry to the study 94.1% of respondents in the booklet group said that they had read the book, 84.0% said that they found it useful, and 68.0% said that they still had a copy. Scores on a 15-item test of knowledge about back pain were significantly higher in the group of patients who had received the booklet than in the control group. The results suggest that the booklet had some effect in altering both the knowledge and behaviour of patients with back pain. The provision of an educational booklet was a method of giving information which was appreciated by both patients and doctors.

Adult↗
PubMed1989

[Primary health services, financing and research].

The capitation method of payment is presently used in five health centres in Belgium, in accordance with the 1963 health insurance law. The position of this experience in the field of primary health care, with its direct impact on concrete and subjective dimensions, implies that its evaluation, even quantitative, should rely on action research methodology. Action-research includes concern for change and involvement of concerned actors with the objectives and the field of the research. The study protocol developed by the Federation of Health Centres is presented. It proposes the parameter "mean total cost by insured person". Presently the study does not progress; reason for this are examined.

Capitation Fee↗
PubMed1988

Are referrals by general practitioners influenced by the availability of consultants?

To investigate variations in the number of outpatients seen in different NHS regions of Great Britain data on numbers of outpatients, number of consultants per 100,000 population, mortality, and prescribing rates were analysed for four specialties: medicine, thoracic medicine, psychiatry, and dermatology. The number of outpatients seen was strongly associated with the provision of consultants in all four specialties and only weakly associated with need for outpatient services as measured by standardised mortality ratios and mean numbers of prescriptions per patient issued by general practitioners. Interpretations of differences in referral rates need to take into account variations in the supply of specialists as a factor that may influence the referral behaviour of general practitioners.

Catchment Area, Health↗
PubMed1986

Factors associated with achieving continuity of care in general practice.

The continuity of care received by 128 patients in four Bristol group practices over a two-year period was measured. A high standard of continuity of care was found for many patients, even though they were registered with large training practices. Patients registered with practices operating personal lists received much better continuity of care than those registered with practices operating combined lists.Patients in the study regarded continuity of care as important, especially if they were registered with practices operating personal lists.All the doctors in the study appeared to regard continuity of care as important, although those operating personal lists were more positive in this view.

Adolescent↗
PubMed1985

Stereological analysis of human parietal cells before and 6 months after vagotomy.

Gastric biopsies from 10 patients were studied before proximal gastric vagotomy (PGV) and 6 months after the operation. The parietal cells were studied light microscopically and electron microscopically, using point-counting stereology. The volume fraction of the mucosa made up of parietal cells was significantly reduced (p less than 0.01) from 13.9% before PGV to 10.6% 6 months after PGV (median values). This reduction corresponded with a decrease of the median cell volume from 4698 microns3 before PGV to 3737 microns3 after the operation (p = 0.01). The ultrastructural composition of the parietal cells was virtually unchanged after the vagotomy, with the exception of a slight but significant reduction of the cell fraction occupied by mitochondria. The fractions of the parietal cell volume occupied by microvilli and tubulovesicular structures were significantly altered during stimulation with pentagastrin. These relative alterations were of the same magnitude before and after PGV.

Adult↗
PubMed1985

Long-term results after excision of fixed subaortic stenosis.

Forty-nine patients underwent surgical excision of fixed subaortic stenosis (discrete fibrous ring and tunnel) between 1968 and 1984 and were followed up for 1 to 16 years (5.8 +/- 4). Twenty-six patients (Group I) had isolated subaortic stenosis and 23 (Group II) had subaortic stenosis and associated cardiac defects. Discrete fibrous ring was present in 46 and tunnel type of obstruction in three patients. For the discrete ring, excision alone was done in 32 patients (four recurrences) and excision with myotomy in 17 (three recurrences). In Group I, there were no operative deaths and one late death from a noncardiac cause. In Group II, one early and two late deaths occurred. The actuarial survival rate for 10 years is 88%. Reoperations were performed in 10 patients, seven for recurrence and three for aortic valve replacement for preexisting aortic regurgitation that had progressed since the primary operation. Cardioplegia was used in 28 patients (one recurrence) and was not used in 21 patients (six recurrences). An operative residual gradient of less than 15 mm Hg was achieved in 25 of 28 patients in whom cardioplegia was used compared to 12 of 21 patients in whom cardioplegia was not used (p = 0.017). These results indicate that complete excision of the ring with the aid of cardioplegia has significantly reduced the recurrence rate of subaortic stenosis (p = 0.033), elimination of the residual gradient at the initial operation has been a significant factor in reducing the recurrence rate (p = 0.017), and addition of myotomy in this series has not altered the outcome.

Adolescent↗
PubMed1984

In vivo uptake of polyisobutyl cyanoacrylate nanoparticles by rat liver Kupffer, endothelial, and parenchymal cells.

Polyalkyl cyanoacrylate nanoparticles were previously developed as a biodegradable, ultrafine, solid drug carrier. Distribution studies in the rat showed an intense and rapid hepatic uptake. This liver accumulation appears to represent, to a certain extent, extracellularly bound nanoparticles. During liver perfusion, 15-20% of the liver-associated nanoparticles were washed out. The cellular distribution of strongly cell-associated nanoparticles was determined. At different intervals after injection of radioactive nanoparticles to rats, the cells were isolated according to a recently developed, low-temperature procedure during which processing of the carrier was inhibited. At all tested times, a relatively intense capture by Kupffer cells in comparison with endothelial and especially parenchymal cells was observed. This distribution pattern was not influenced by the size of the nanoparticles (0.08-0.215-micron diameter). This specific interaction of nanoparticles with Kupffer cells opens possibilities for the treatment of some parasitic diseases involving this cell type.

Animals↗