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Biomedical subjects

I Magnusson

Publications and source records attributed to I Magnusson.

At least 91 records · Page 5Linked to original sources
PubMed1989

Pathways of hepatic glycogen formation in humans following ingestion of a glucose load in the fed state.

The relative contributions of the direct and the indirect pathways to hepatic glycogen formation following a glucose load given to humans four hours after a substantial breakfast have been examined. Glucose loads labeled with [6-(14)C]glucose were given to six healthy volunteers along with diflunisal (1 g) or acetaminophen (1.5 g), drugs excreted in urine as glucuronides. Distribution of 14C in the glucose unit of the glucuronide was taken as a measure of the extent to which glucose was deposited directly in liver glycogen (ie, glucose----glucose-6-phosphate----glycogen) rather than indirectly (ie, glucose----C3-compound----glucose-6-phosphate----glycogen). The maximum contribution to glycogen formation by the direct pathway was estimated to be 77% +/- 4%, which is somewhat higher than previous estimates in humans fasted overnight (65% +/- 1%, P less than 0.05). Thus, the indirect pathway of liver glycogen formation following a glucose load is operative in both the overnight fasted and the fed state, although its contribution may be somewhat less in the fed state.

Acetaminophen↗
PubMed1989

Efficacy of Perimed antibacterial system on established gingivitis. (I). Clinical results.

A 6-month, double-blind controlled study was conducted on 101 subjects to determine the effect of Perimed antibacterial system, containing povidone-iodine (PVP-I) and hydrogen peroxide (H2O2), on established gingivitis. Subjects were randomly assigned to one of 4 treatment groups: PVP-I/H2O2, PVP-I/H2O, H2O2/H2O or H2O. Gingivitis was assessed by the papillary bleeding score (PBS) and plaque by a modified Quigley-Hein plaque index (PI) at baseline, 3, 12 and 24 weeks. The average baseline PBS and PI for the 4 groups ranged from 2.16-2.31 and 2.87-2.90, respectively. After baseline evaluation, subjects received a supra-gingival scaling and a subgingival irrigation with their respective rinse. Daily rinses were supervised and subgingival irrigation was repeated every 3 weeks. Duncan's multiple range test determined which groups differed from each other. The mean PI at 24 weeks was lower than at baseline in all groups. PVP-I had the lowest PI at all time points. The mean PBS at 24 weeks was 1.48 for PVP-I, 1.62 for H2O2, 1.88 for H2O and 1.34 for PVP-I/H2O2, a reduction from baseline of 31%, 27%, 18%, and 38% respectively. The difference between the PBS for PVP-I/H2O2 and H2O control was significant at each evaluation. There was a 70% reduction in sites with PBS greater than or equal to 3 for PVP-I/H2O2 between baseline and 24 weeks compared to a 34% decrease in the H2O group. It was concluded that the use of Perimed could be a beneficial adjunctive treatment for the prevention and control of gingivitis when used with routine oral hygiene procedures.

Adolescent↗
PubMed1989

Effect of non-surgical periodontal therapy combined with adjunctive antibiotics in subjects with "refractory" periodontal disease. (I). Clinical results.

The aim of the present study was to evaluate the clinical effect of non-surgical periodontal therapy with the adjunct of a selected antibiotic in subjects with refractory periodontitis. 10 subjects were selected for the study; all had a history of periodontal surgery, tetracycline therapy, and regular maintenance by a periodontist. Clinical registrations including gingival index, plaque index, presence of bleeding and suppuration, pocket depth, and duplicate measurements of attachment level were performed at baseline and at monthly intervals. When disease activity was detected based on the tolerance method, a bacterial sample was taken from the active site and its susceptibilities to a number of antibiotics were determined. For the selected 10 subjects, Augmentin was the antibiotic of choice. Each subject received 750 mg/day for 2 weeks, during which time a full-month scaling and root planing was performed under local anesthesia. Clinical re-evaluation was performed after 3, 6, 9 and 12 months. At the time disease activity was detected, the average loss of attachment at all active sites was 2.2 mm, and the increase in pocket depth 1.5 mm. At 3 months post-therapy, these sites had regained 2 mm of attachment which remained stable through the 12-month examination. Pocket depths decreased 2.5 mm over the first 6 months and then stabilized. The frequency of all sites that gained 1 mm or more of attachment increased by approximately 10% over the first 9 months following therapy. The frequency of all sites that decreased 1 mm or more in pocket depth increased approximately 15% over the same period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Modulation of colonization by black-pigmented Bacteroides species in squirrel monkeys by immunization with Bacteroides gingivalis.

Periodontal diseases are inflammatory responses thought to be triggered by specific microorganisms colonizing in the gingival crevice. Theoretically, periodontal diseases could be prevented if the etiologic organisms were not allowed to colonize the subgingival area. The humoral immune response is one mechanism which may modulate bacterial colonization in the gingival crevice. To test the effect of systemic humoral immunity on subgingival colonization by bacteria, squirrel monkeys (Saimiri sciureus) were immunized with Bacteroides gingivalis, a black-pigmented Bacteroides sp. and putative periodontal pathogen. Immunized and sham-immunized monkeys were orally inoculated with 10(10) viable B. gingivalis during ligation of five teeth in one quadrant with bacterium-soaked suture material and distribution over the entire dentogingival margin. Immunization resulted in an increased level of immunoglobulin G anti-B. gingivalis in serum and was associated with a strong trend toward a statistically significant reduction in colonization of the gingival crevice by black-pigmented bacteroides.

Animals↗
PubMed1988

Pentose pathway in human liver.

[1-14C]Ribose and [2-14C]glucose were given to normal subjects along with glucose loads (1 g per kg of body weight) after administration of diflunisal and acetaminophen, drugs that are excreted in urine as glucuronides. Distributions of 14C were determined in the carbons of the excreted glucuronides and in the glucose from blood samples drawn from hepatic veins before and after glucagon administration. Eighty percent or more of the 14C from [1-14C]ribose incorporated into the glucuronic acid moiety of the glucuronides was in carbons 1 and 3, with less than 8% in carbon 2. In glucuronic acid from glucuronide excreted when [2-14C]glucose was given, 3.5-8.1% of the 14C was in carbon 1, 2.5-4.3% in carbon 3, and more than 70% in carbon 2. These distributions are in accord with the glucuronides sampling the glucose unit of the glucose 6-phosphate pool that is a component of the pentose pathway and is intermediate in glycogen formation. It is concluded that the glucuronic acid conjugates of the drugs can serve as a noninvasive means of sampling hepatic glucose 6-phosphate. In human liver, as in animal liver, the classical pentose pathway functions, not the L-type pathway, and only a small percentage of the glucose is metabolized via the pathway.

Acetaminophen↗
PubMed1988

Description and clinical evaluation of a new computerized periodontal probe--the Florida probe.

A new periodontal probing system has been developed which incorporates the advantages of constant probing force, precise electronic measurement to 0.1 mm and computer storage of the data. The system includes a probe handpiece, displacement transducer with digital readout, foot switch, computer interface and personal computer. A unique movable arm design enables the probe handpiece to maintain smooth operation and makes it easy to clean and sterilize. Electronic recording of the data (actuated by pressing a foot switch) eliminates errors which occur when probe tip markings are read visually and the data are called to an assistant. Computer storage and analysis of the data facilitates detecting changes in pocket depth and attachment level by rapidly comparing data recorded at different visits. The system was evaluated in 3 experiments using a 0.4 mm diameter tip and a 25 g probing force. The standard deviation of repeated pocket depth measurement was less (0.58 mm versus 0.82 mm) than that of a common probe. With paired readings referenced to an occlusal stent, the standard deviation of repeated attachment level measurements was 0.28 mm. A loss of attachment level was detected to a certainty of 99% with less than a 1 mm change. This is a significant improvement over common probes, which require a 2-3 mm change for equivalent positive identification of change in attachment level.

Computers↗
PubMed1988

Correlation between electronic and visual readings of pocket depths with a newly developed constant force probe.

The purpose of this study was to compare probing measurements obtained using a newly developed constant force electronic probe, which eliminates errors of visual reading and variable force, to those obtained using a standard periodontal probe. The probe was connected to a digital readout through a linear variable differential transformer; the digital readout was connected to a printer and a foot switch. When the probe was in position and the foot switch depressed, the pocket depth was printed to the nearest 0.1 mm. 12 subjects with minimal to early periodontitis were selected for the study. The pocket depths of each patient were recorded electronically utilizing a constant force of 25 g, and conventionally using the same instrument in a "locked" position and visual reading. Probings were performed on each subject by 3 different examiners, on 3 separate occasions 2-3 days apart. The results showed a high correlation between manual and electronic probing. The average correlations for the 3 investigators between examinations were consistently higher for the electronic probings. In comparing the 3 examiners to each other, consistently higher correlations were found for the electronic pocket readings. Correlations for single-rooted teeth were lower for all 3 examiners. The pocket depth measurements recorded when using the manual probe with visual readings were consistently deeper than those obtained using the electronic probe with computer readings. It was concluded that the reproducibility of measurements obtained with the electronic probe was significantly superior to that obtained with a manual probe.

Adult↗
PubMed1988

Attachment level measurements with a constant force electronic probe.

The purpose of the present investigation was to evaluate the reproducibility of probing attachment level measurements using a newly developed constant force electronic probe. The probing force was preset at 25 g (probe diameter 0.4 mm) and was connected to a computer through a variable differential transformer. The measurements were performed on 10 patients with minimal signs of periodontal disease, using individually made acrylic stents. When the probe was in place and a foot switch depressed, the measurement was stored on the computer to the nearest 0.1 mm. The measurements were performed by one periodontist and one hygienist during one visit, and were then repeated by the same periodontist and another hygienist during a second visit. The results showed high correlations between the periodontist and the hygienist during one visit, between the two visits for the periodontist, and between the two hygienists at two different visits. The subject threshold for attachment loss was calculated according to Haffajee and co-workers, and was found to average 0.84 mm for the measurements performed by the periodontist and the hygienist during the same visit. For the periodontist during two separate visits and for the two different hygienists, the average threshold was 0.99 and 1.02 mm, respectively. Duplicate measurements were also performed by one periodontist at one visit on 10 patients with advanced periodontal disease. The average subject threshold for these patients was 0.60 mm. It may be concluded that with the constant force electronic probe, loss of attachment can be detected earlier than when conventional instruments are used.

Dental Hygienists↗
PubMed1988

Natural occurrence of black-pigmented Bacteroides species in the gingival crevice of the squirrel monkey.

The objective of this study was to determine whether the squirrel monkey (Saimiri scuireus) is indigenously colonized with black-pigmented bacteroides (BPB) resembling human Bacteroides gingivalis and Bacteroides intermedius (suspected periodontal pathogens) and to determine the usefulness of the squirrel monkey as an in vivo model for studying colonization by putative pathogens. We assayed the subgingival plaques of 138 monkeys of various ages and in four different colonies for the presence of anaerobic BPB microorganisms. We also tested half the animals for the presence of Actinobacillus actinomycetemcomitans. Clinical indices and levels of serum antibody to B. gingivalis were recorded. We detected BPB in 50% of the animals and A. actinomycetemcomitans in 69% of the animals. The presence of BPB was generally associated with increased age, increased gingival index, presence of calculus, and increased levels of serum antibody. These data indicate that the squirrel monkey may be a good model for studying the parameters of natural infection of the gingival crevice with suspected periodontopathogenic BPB microorganisms.

Age Factors↗
PubMed1988

New attachment formation following controlled tissue regeneration using biodegradable membranes.

The present study evaluated the potential for reestablishment of connective tissue attachment after exclusion of the gingival connective tissue and epithelium during healing after periodontal surgery in a dog model. Buccal mucoperiosteal flaps were elevated in all four premolar regions in two dogs. The buccal bone was reduced to approximately 25% of its original level on 24 roots. Before the elevated flaps were replaced and sutured, membranes were adjusted to cover the exposed root surfaces. On eight surfaces Millipore filters were used and on eight surfaces biodegradable polylactic acid membranes were used. No membranes were placed over the remaining eight root surfaces which served as controls. After two months of healing, the animals were sacrificed and all the roots were subjected to histological analysis. In all of the roots covered with the polylactic acid membrane, newly formed cementum with inserting collagen fibers was observed and covered on the average 46% of the initial defect. Newly formed bone covered 39% of the initial defect. The roots covered by Millipore filters were characterized by significantly less new attachment and bone. In the control roots only minor new attachment was found in the bottom of the defect in some roots. The results suggest that the establishment of a connective tissue attachment is clearly favored by the placement of a polylactic acid membrane to exclude the epithelium and gingival connective tissue during healing.

Alveolectomy↗
PubMed1987

Quantitation of the pathways of hepatic glycogen formation on ingesting a glucose load.

Diflunisal, 5-(2',4'-difluorophenyl)salicylic acid, excreted in urine as its glucuronide, was given to normal humans (n = 6) along with a glucose load specifically labeled with 14C. Glucuronide excreted by each subject was reduced to its glucoside and glucose from it degraded to yield the distribution of 14 C in its six carbons. Randomization of the 14C from the specifically labeled glucose was taken as a measure of the extent to which glucose was deposited indirectly (i.e., glucose----lactate----glucose----6-P----glycogen), rather than directly (i.e., glucose----glucose-6-P----glycogen). The maximum contribution to glycogen formation by the direct pathway was estimated to be 65 +/- 1%, on the assumption that glucuronide and glycogen are derived from the same hepatic pool of glucose-6-P in liver. Evidence that supports that assumption was obtained by comparing the randomization of 14C in the urinary glucuronide with that in glucose in blood from the hepatic vein of four of the subjects before and after they were given glucagon. Other evidence supporting the assumption was obtained by comparing in two subjects 3H/14C ratios in glucose from hepatic vein blood before and after glucagon administration with that in urinary glucuronide, having labeled the uridine diphosphate (UDP)-glucose in their livers with 14C by giving them 1-[14C]galactose and their circulating glucose with 3H by giving a 5-[3H]glucose-labeled load. It is concluded that glucuronide formation in humans can be used to trace glucose metabolism in the liver, and that in humans the indirect pathway of glucose metabolism is active.

Administration, Oral↗
PubMed1987

Secretin and somatostatin in the treatment of upper gastrointestinal haemorrhage.

Secretin inhibits gastric secretion of acid and gastrin in dog and a physiological role of secretin as an enterogastrone has been suggested in this species. In man there are diverging results concerning the effect of secretin on gastric secretion. Secretin has been used in patients with upper gastrointestinal bleeding and positive results have been reported, but the patients included in these studies cannot be considered as massive bleeders. Until now no double-blind study comparing secretin with placebo has been reported. Somatostatin decreases splanchnic blood flow and gastric secretion in man. Somatostatin seems to be effective in achieving initial haemostasis in patients with bleeding oesophageal varices. The peptide has also been shown to stop severe and persistent peptic ulcer haemorrhage and to stop bleeding in patients treated with steroidal and non-steroidal anti-inflammatory drugs. In one double-blind trial in patients with upper gastrointestinal bleeding, somatostatin had no effect on either the number of emergency operations or the number of rebleedings. In another double blind study, when somatostatin was compared with placebo in patients with massive upper gastrointestinal bleeding, the peptide reduced the number of emergency operations. In conclusion, most studies show positive effects of somatostatin on variceal and peptic ulcer haemorrhage.

Animals↗
PubMed1987

Massive hematemesis due to an aorto-oesophageal fistula. Case report.

A patient with massive hematemesis due to an aorto-oesophageal fistula is presented. An aorto-oesophageal fistula is mostly a fatal disease. In the literature it is pointed out that recognition of the clinical syndrome with midthoracic pain, massive arterial hemorrhage and exsanguination after a symptom-free interval might ameliorate the prognosis. In the reported patient the correct diagnosis was not immediately suspected. The patient, however, survived a long operation and exsanguination without any major postoperative complications or sequelae.

Aortic Diseases↗
PubMed1985

Sampling of subgingival microbiota for dark-field microscopy.

The aim of the present investigation was to study the validity of 2 different methods of sampling the subgingival microbiota. The composition of the flora was estimated using the dark-field microscope. Subgingival samples were obtained using either a curette or a Hamilton microsyringe for a subgingival washing. The method of determination of the composition of the subgingival microorganisms was found to be very reproducible when the same investigator performed the counting. Samples obtained by the washing technique had a slight but significantly higher proportion of coccoid cells when compared to samples obtained by curette. The calculation of the reproducibility of the washing technique as assessed in 6 immediately repeated samples from the same sites yielded a coefficient of variation of 40% for spirochetes and motile rods. When 9 repeated samples from each of 28 sites (14 with a curette, 14 with washing) were studied over a period of 32 days, no systemic alterations were observed in the % of spirochetes and motile rods. The variation within each individual site was high. For curette samples and washing samples, the coefficients of variation for spirochetes and motile rods were 85% and 63%, respectively. The present investigation clearly demonstrated that care should be taken in the interpretation of single samples of subgingival microbiota. A more relevant picture of the actual situation is achieved when trends of repeated samples over time are studied.

Bacteria↗
PubMed1985

Subgingival spirochete and leukocyte counts as indicators of response to therapy.

The aim of this study was to determine whether changes in probing attachment levels are related to subgingival spirochete or leukocyte counts in periodontal pockets. Following initial clinical recordings and therapy consisting of oral hygiene instruction and root debridement, the probing attachment levels of proximal sites of 120 single-rooted teeth in 7 patients were measured every 3 months for 12 months. The measurements of each site were subjected to regression analysis, which determined whether the site was deteriorating, improving, or non-changing. Subgingival washings were taken of 19 deteriorating, 22 improving, and 127 non-changing sites to determine the number and % of spirochetes and the number of leukocytes at each site. Improved probing attachment levels were associated with reduced numbers of spirochetes and leukocytes. However, the ranges of individual measurements of subgingival washing variables overlapped considerably between groups. Spirochete and leukocyte counts related better to the 12-month probing depths than to changes in probing attachment levels during the preceding 12 months. These findings suggest that none of the tested subgingival washing parameters are suitable indicators of changes in attachment levels on an individual site basis.

Gingiva↗
PubMed1985

Antimicrobial irrigation of deep pockets to supplement oral hygiene instruction and root debridement. I. Bi-weekly irrigation.

64 sites with probing pocket depth greater than or equal to 6 mm from 11 patients were treated with plaque control instruction and one episode of root planning. Subsequently, selected sites in each patient were irrigated with either chlorhexidine, tetracycline, saline or served as non-irrigated control sites. Irrigation immediately followed instrumentation, and was repeated every 2 weeks for 24 weeks. Healing was monitored at 8, 16, and 24 weeks clinically and at 7, 15, and 23 weeks with subgingival washings for determination of % as well as total number of spirochetes. The following changes were apparent from comparing pooled site means at 24 weeks with pretreatment data: (1) bleeding sites decreased from 62 of 64 sites initially to 22 of 64 at 24 weeks; (2) spirochetes decreased from 34% to 2%; (3) probing pocket depths decreased from 7.6 to 4.7 mm; (4) probing attachment levels showed a gain of 1.2 mm. The improvement of the chlorhexidine and tetracycline irrigated sites was similar to that of the saline irrigated and non-irrigated control sites. Thus, biweekly chlorhexidine, tetracycline or saline irrigation of deep pockets did not appear to augment the effects of non-surgical periodontal therapy.

Adult↗