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Biomedical subjects

M Roland

Publications and source records attributed to M Roland.

At least 109 records · Page 6Linked to original sources
PubMed1984

Degradation of poly (isobutyl cyanoacrylate) nanoparticles.

Poly(isobutyl cyanoacrylate) nanoparticles were prepared. They were degraded in two enzyme-free media at pH 7 and 12 in the presence of rat liver microsomes. The conventional formaldehyde-producing degradation route was studied, and showed a very low efficiency. Another pathway, consisting of ester hydrolysis, was identified and studied. In contrast to the formaldehyde pathway, ester hydrolysis was shown to be catalysed by enzymes. Finally, the release rate of adsorbed actinomycin from nanoparticles was proved to correlate exactly with the degradation rate of the polymer.

Animals↗
PubMed1984

Short-term use of a medicated douche preparation in the symptomatic treatment of minor vaginal irritation, in some cases associated with infertility.

Fifty-six women with minor vaginal irritation, some associated with infertility, and with negative wet mount examination for common vaginal pathogens, used a disposable povidone-iodine-containing preparation (Betadine Medicated Douche) in a one-week trial. Of the 185 patient complaints, which included discharge, odor, pruritus, erythema, burning, and discomfort, 94 percent cleared completely and 4 percent were partially relieved. Odor cleared completely in 97 percent of affected cases and pruritus, discharge and chafing in 96, 91, and 100 percent, respectively. In all, 98 percent of the patients responded favorably. Those who became asymptomatic included women with past histories of repeated vaginal infections or on oral contraceptives, as well as a diabetic and patients with intrauterine devices. The douche caused no adverse effects and was well accepted by the patients. The present results favor short-term trial of the povidone-iodine douche in minor vaginal irritation of unknown etiology, before full laboratory investigation is undertaken.

Adult↗
PubMed1984

Morphometric studies of human parietal cells before and 7 days after proximal gastric vagotomy.

In nine patients, acid titration tests and gastric biopsy specimens were studied before proximal gastric vagotomy (PGV) and 1 week after the operation. When postoperative biopsy specimens were compared with the preoperative ones, no change was found in the thickness of the mucosa. The volume fraction of the mucosa made up of parietal cells was significantly reduced (p less than 0.01) from 13.8% before PGV to 11.2% after PGV (median values). Both before and after the operation, stimulation with pentagastrin was followed by a significant increase in the relative volume of microvilli in parietal cells and a significant reduction of the relative volume of tubulovesicular structures. The magnitude of this ultrastructural response to pentagastrin was similar before and after PGV. The relative volume of lysosome-like structures was significantly increased in parietal cells postoperatively. With this exception, no significant alteration was found when comparing the ultrastructure before and 7 days after PGV.

Adult↗
PubMed1984

[Odontogenesis in the human fetus: an echographic study].

During real-time ultrasound observation of swallowing movements in the human fetus, changes in the echostructure of the jaws were detected. Dense linear echoes (2-6 mm) arose symmetrically in the superior and inferior jaws from the median to the distal level with increasing gestational age. Their localisation and onset suggested they might represent tooth germs. The comparison between radiography after birth and pre- and postnatal echography confirmed that these particular echoes were indeed calcified tooth germs. The implications of this observation will be discussed in terms of fetal growth maturation and gestational age.

Deglutition↗
PubMed1984

Prophylactic regimens in colorectal surgery. Comparison between metronidazole used alone or in combination with either ampicillin or doxycycline.

Sixteen hospitals are participating in this study, that started in October 1982 and will be concluded when 456 patients have been admitted. The study includes patients eligible for elective colorectal surgery. Inclusion criteria, surgical techniques, definition of recognizable infection, sampling of specimens for bacteriological investigations, bacteriologic techniques, and evaluation criteria were standardized. Patients were divided into 2 main groups. Patients in Group 1 received either a single intravenous dose of 1500 mg metronidazole or this dose was combined with a single, intravenous dose of 6 g ampicillin. Patients in group 2 received either a single intravenous dose of 1500 mg metronidazole or this dose combined with a single intravenous dose of 400 mg doxycycline. Dosage regimens were allocated randomly. The current results concern 136 patients. Postoperative infections were seen in 6.7% of the patients receiving metronidazole alone, and 2.9% of the patients receiving metronidazole + ampicillin (Group 1). In Group 2, postoperative infection occurred in 17.1% of the patients receiving metronidazole alone, and in 2.7% of those receiving metronidazole + doxycycline.

Adult↗
PubMed1983

Severe toxic reaction to tinidazole.

A physician aged 44 years participated as a volunteer in pharmacokinetic studies with tinidazole (FASIGYN, Pfizer). He received 1600 mg of the drug as an intravenous infusion over 80 min. Shortly afterwards, he fainted and was unconscious for about 10 s. The attack was followed by low blood pressure, nausea and tiredness for several h. The serum concentration of tinidazole was 35.4 mg/l when the attack started. Blood tests showed a normal immunoglobulin E level, and a transient fall in the concentration of complement factor C3 after the infusion. It is concluded that tinidazole caused an acute toxic reaction with subsequent activation of complement factors.

Adult↗
PubMed1983

A study of the natural history of low-back pain. Part II: development of guidelines for trials of treatment in primary care.

In a prospective study of 230 episodes of low-back pain presenting in primary care, the natural history of the symptom of low-back pain has been described. Clinical features predictive of outcome have been identified in order to define groups of patients who were relatively homogeneous with respect to the outcome of the episode. A Disability Questionnaire performed more satisfactorily as an outcome measure than either absence from work or a simple pain-rating scale. Guidelines for future trials of treatment of back pain in primary care are described.

Adolescent↗
PubMed1983

Morphometric studies of parietal cells during basal conditions and during stimulation with pentagastrin in healthy subjects.

A morphometric study was carried out of parietal cells from seven healthy volunteers. Under gastroscopical control, biopsies were taken with a hydraulic capsule before and 30 min after stimulation with pentagastrin. No significant change was found in the absolute volume of the parietal cells or their nuclei during stimulation. When median values for the ultrastructure were compared, microvilli constituted 4.6% of the parietal cell volume during basal conditions and 9.3% during stimulation with pentagastrin. Tubulovesicular structures constituted 10.9% of the cell volume during basal conditions and 1.9% during stimulation. These ultrastructural differences between basal and stimulated conditions were statistically significant, with P = 0.02 using Wilcoxon's test for paired data. Similarly significant changes were found in the membrane area of the secretory canaliculus and the tubulovesicular structures.

Adolescent↗
PubMed1982

Biliary excretion of bisacodyl and picosulphate in man: studies in gallstone patients after biliary tract surgery.

Bisacodyl (=BIS) and picosulphate (=PICO) have been given perorally to postoperative gallstone patients, who have undergone biliary tract surgery with the insertion of an indwelling T-tube. The doses corresponded to 7.7 mg of their common free diphenol desacetylbisacodyl (=DES). The bile was sampled in hourly fraction from the external limb of the T-tube; these fractions were analysed by a modification of the HPLC method previously used to study biliary excretion in the rat. In the BIS-patients (n=8), DES in conjugated form occurred in significant concentration already in the first fractions; peak excretion values equivalent to 4-8 microgram DES/ml bile were reached in 2-5 hours. Unchanged BIS could not be detected, and the concentration levels of unconjugated DES were insignificant. The PICO-patients (n=8) on the other hand showed low DES concentrations (conjugated + free less than or equal to 0.5 microgram DES/ml) in all fractions, or low initial concentrations followed by a more or less pronounced rise in the later fractions. These results are, qualitatively, as in the rat. However, the dose fractions excreted in bile (assuming a total hepatic output of 50ml/hours) seem smaller than those to be expected from rat experiments, at least as far as BIS is concerned.

Adult↗