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Biomedical subjects

B Siegrist

Publications and source records attributed to B Siegrist.

10 recordsLinked to original sources
PubMed2001

Inhibition of human angiogenesis with heparin and hydrocortisone.

Angiogenesis is a critical determinant of tumor growth and the development of metastases. Heparin, steroids, and heparin/steroid combinations have been used in a variety of in vitro models and in vivo in animal models as effective inhibitors of angiogenesis. We tested heparin, steroid and heparin/steroid combinations at a variety of concentrations to determine their effect on the human 'angiogenic switch' from a resting to a proliferative endothelium in vessels from three placentas (initiation), and the effect of these compounds on the subsequent growth of a human angiogenic response (promotion). Using full-thickness human placental vein discs cultured in three-dimensional fibrin-thrombin clots, we demonstrated that heparin (300, 3000 micrograms/ml), steroid (350, 3500 micrograms/ml), and combinations of heparin/steroid at these doses effectively blocked both initiation and promotion of a human angiogenic response in a dose-dependent fashion. We also demonstrated that high-dose steroid or heparin/steroid treatment for 15 days resulted in disruption of vessel integrity, while treatment with heparin alone produced a suppressed growth rate but had intact vessel architecture. High-dose heparin/steroid treatment could also disrupt a developed angiogenic response and retard further development of an angiogenic response following the cessation of treatment.

Angiogenesis Inhibitors↗
PubMed2000

Infections within the peritoneal cavity: a historical perspective.

Physicians in antiquity dreaded abdominal infections. Despite the fact that peritonitis was extremely common, reports of successful surgical interventions were only anecdotal before the past century. Medicine's comprehension of the pathophysiology of the peritoneal cavity is still evolving. The history of our understanding of the process could be considered to be as recent as the current literature. Despite this, the mortality rates for patients with secondary peritonitis have fallen in the last century from almost 100 per cent to less than 10 per cent.

Egypt↗
PubMed2000

Penetrating neck injuries.

Penetrating neck trauma may be managed operatively or nonoperatively, depending on precise anatomic location. Conservative management of zone II injuries is currently an issue under debate. We present a brief case report followed by a description of the current strategies for operative exploration and diagnostic maneuvers in penetrating neck injuries. Support for both expectant and operative management of zone II injuries is given. We conclude that for zone II injuries, mandatory exploration by an experienced surgeon is a safe approach and that conservative management must be undertaken with extreme caution.

Adult↗
PubMed1992

Periodontal conditions in Swiss Army recruits.

The purpose of the present study was to assess the oral hygiene and periodontal conditions of a young male population representative for Switzerland. 757 Swiss Army recruits were examined for their oral health status including the assessment of Plaque Index (PlI), Retention Index (RI) and Sulcus Bleeding Index (SBI) as well as Probing Depth (PD) and Loss of Probing Attachment (LA). All the teeth of the right maxillary and mandibular dental arch were evaluated on four aspects. One recruit yielded a status of juvenile periodontitis and was excluded from further analysis. 2.3% of the teeth had been lost, mainly as a result of orthodontic therapy. Mean PlI and SBI for all 756 recruits approximated 0.6, while the mean RI was around 0.1. The mean PD was 2.3 mm, and the mean LA of 0.9 mm was measured. PD and LA were slightly higher on proximal than on buccal or oral aspects. Site specific analysis for all parameters are presented. Since only 0.4% of the recruits showed probing depths of greater than or equal to 5 mm and only 1% of the subjects showed LA greater than or equal to 4 mm on any surfaces it may be concluded that severe signs of chronic adult periodontitis are absent in 99% of young male Swiss citizens.

Adult↗
PubMed1986

Safety and antibacterial properties of controlled release SnF2.

Two clinical studies were performed to evaluate the safety and efficacy of an intracoronal device for the controlled release of SnF2. SnF2-polycarboxylate cement, containing approximately 72 mg F-, was placed in subjects' molars requiring two-surface restorations. In the trial for safety, eight subjects had the restoration in place for 34 days. The salivary fluoride levels were elevated to a mean of 0.3/10(6) over the experimental period. Urinary fluoride levels were only above baseline levels during the first few days. The restoration's physical properties were adequate; however, subjects experienced gingival irritation in areas where the restoration was contacted with gingiva. In the trial for efficacy, fourteen subjects had either a SnF2-polycarboxylate or a placebo restoration placed in a molar tooth during a 2 week period of no oral hygiene. During the experimental period, the control subjects had higher levels of salivary total CFU, Streptococcus sanguis and Streptococcus mutans: while the subjects with the SnF2 restoration had increased S. sanguis and decreased S. mutans levels. No differences in G.I. or PL 1 scores were noted between groups. Further development of this controlled release system should include using the SnF2-polycarboxylate restoration in more than one tooth per subject to increase the fluoride reservoir, and not allowing the restoration to contact gingival tissues.

Adult↗
PubMed1982

The effect of supragingival plaque control on the composition of the subgingival microbial flora in ligature-induced periodontitis in the monkey.

The influence of supragingival plaque control on the subgingival microflora and clinical parameters of ligature-induced periodontitis in the Cynomolgus monkey was investigated. No clinical changes were observed during the six-week experimental period. The total cultivable flora and the proportions of total black-pigmented Bacteroides (BPB) and asaccharolytic black-pigmented Bacteroides decreased significantly in the cleaned test sites as compared to those in the non-cleaned controls. The study suggests that six wk of supragingival plaque control in the presence of periodontal disease may alter the periodontitis-associated microflora in the monkey, but not sufficiently to alter clinical signs of disease in this time period.

Animals↗