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Biomedical subjects

R Heinrich

Publications and source records attributed to R Heinrich.

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

[The microbial colonization of the dentin close to the pulp in the permanent teeth following deep caries therapy].

In a clinical microbiological study the microflora of cavity floors in 41 permanent teeth was investigated after several month of caries excavation and with or without Calxyl application on hard dentine prior sealing with zincphosphatecementum and amalgam. The cavity floors were only lowly infected. Actinomycetes or acidogenic and aciduric streptococci and lactobacilli dominated in the CFU. After application of Calxyl actinomycetes (A. israelii) were found 3-fold more frequently in the remaining population than streptococci (S. mutans) and lactobacilli. Without application of Calxyl their ratio was 1:1. S. mutans seems to be important for the carious progression in dentin.

Actinomyces↗
PubMed1990

[Root caries--scanning electron microscopic observations].

Sound and carious root surfaces of 24 extracted human teeth with extensive periodontal attachment loss were examined by SEM. The microflora covering the radicular surfaces was a complex flora consisting of filamentous and fusiform bacteria, short and long rods. Cocci and coccoid bacteria were observed on root surfaces. Bacterial invasion in the exposed peripheral root dentin was delayed by sclerotic dentin.

Adult↗
PubMed1990

[Prevalence of root caries in a healthy adult population].

An epidemiological study involving 963 subjects aged 25 to 64 years revealed at least one carious and/or filled root surface in 40.2% of all females and in 42.7% of all males. The number of teeth and tooth surfaces affected by root caries increases continuously with age. In relation to the total number of teeth, males display a higher prevalence of root caries than females, with the exception of men aged between 55 and 64. High-risk susceptibility shows no correlation with age, although there are more surfaces at risk in males. Independent of the sex, root caries prevalence is highest in the molars and premolars of the mandible and in the canine of the maxilla; lower incisors are the teeth with the least caries involvement. Labial root surfaces are most frequently affected by caries in the mandible; the prevalence rate is twice as high in males than females. The lingual surfaces of maxillary molars of females and the proximal and buccal surfaces of incisors of males are the most frequently affected tooth surfaces.

Adult↗
PubMed1990

The structure of metabolic systems: a theoretical approach.

A theoretical approach is presented to predict the structural design of enzymatic reaction systems. It is based on the hypothesis that the kinetic properties of enzymes and of other functionally important proteins have been optimized during evolution so that the contemporary cellular metabolic systems are operating at an optimal state. As simple but instructive example we consider the optimization of the stationary flux rate of a single enzyme. In contrast to previous studies a more realistic enzymatic rate equation has been chosen according to HALDANE's reaction scheme.

Enzymes↗
PubMed1989

Influence of prostaglandin E1 on muscular tissue-PO2 in patients with diabetic gangrene.

Intraarterial infusions of short acting vasoactive drugs have been established in the treatment of peripheral occlusive disease. We studied the effect of prostaglandin E1 on the tissue pO2 of the tibialis ant. muscle. Using a fast responding polarographic pO2-probe of the hypodermic needle type, tip diameter 300 microns, we made tissue pO2 investigations in 9 patients with diabetic gangrene. pO2-measurements were done before, during and after administration of 0.2 microgram PGE1/min i.a.. PGE1 led to a slight decrease of the mean muscular pO2 during application followed by a reincrease after the end of infusion. It is known that intraarterial PGE1 infusion leads to an increase of transcutaneous pO2 of the forefoot. Our results show, that there is no increase of tissue pO2 of the tibialis ant. muscle. The reason might be a changed distribution of blood flow in favour of an increased oxygenation of the skin due to PGE1 administration.

Aged↗
PubMed1989

Development of muscular tissue PO2 after vascular reconstructive surgery.

Using a fast responding polarographic pO2-probe of the hypodermic needle type with a tip diameter of 300 microns we investigated the influence of vascular reconstructive surgery on the tissue pO2 of the tibialis ant. muscle. In 10 patients suffering from a peripheral occlusive disease state II-III according to FONTAINE measurements of tissue pO2, pain free walking distance and doppler-index were done preoperatively, 2 weeks and 6 weeks after surgery. The results show that reconstructive vascular surgery leads to an immediate improvement of the doppler-index. In contrast to that there is a time dependent increase of the mean tissue pO2 in the tibialis ant. muscle. This development of muscular oxygenation coincides with an increasing walking distance.

Female↗
PubMed1989

[How does the rate of participation in epidemiologic research affect oral health data?].

The question to which extent an unintended selection is linked with incorrect estimations of oral disease indicators by the readiness of subjects to participate is looked into within the framework of an epidemiological study. 896 primarily cooperative subjects and 70 originally noncooperative subjects aged from 25 to 64 years were examined. According to statistics, non-cooperative subjects were found to have more caries-infected teeth and less teeth filled. Generally, a smaller degree of dental care could be detected in these subjects, which should cause a critical discussion of the hitherto published parameters of oral diseases.

Adult↗
PubMed1989

[Is there a connection between coronal and root caries involvement?].

The relationship between coronal and root caries was analyzed in a sample of 963 people aged 25 to 64 years. Subjects with root caries had fewer teeth, more teeth with untreated coronal caries, and more teeth which need conservative treatments and extractions than did people with no root caries. In the age older than 55 years those with root caries had more teeth in the average of 2.5 teeth for both sexes. The other parameters of dental health showed the same differences compared with younger subjects.

Adult↗
PubMed1989

[Prevalence of root caries in women].

An epidemiological study involving 764 women aged from 25 to 64 years revealed at least one carious and/or filled root surface in 40% of all subjects. The number of teeth and tooth surfaces affected by root caries continuously increased with age. Prevalence has tripled after the age of 45. By contrast, the risk of caries shows no dependence on age. The highest root caries prevalence is found in the molars of the mandible and in the canines of the maxilla; the lowest attacked tooth type is in the lower incisors. Root caries is most frequently found on all buccal surfaces of molars in the mandible and on the oral surfaces of molars in the maxilla.

Adult↗
PubMed1989

[Cotton roll or rubber dam in endodontic treatment?].

In a clinical-microbiological study of the bacterial flora on deep areas of carious dentine in deciduous and permanent human teeth the aseptic rubber dam technique was given preference to remove successive samples of dentine from the cavity floors. The application of the rubber dam made it possible to establish and maintain a surgically clean field of operation and were an effective safeguard against contamination through seepage of saliva.

Dentistry, Operative↗
PubMed1989

[Microbial colonization of carious progression stages in the dentin of human teeth--a controlled therapeutic study].

In a controlled clinical trial the microflora of the cavity floor of 70 primary lower second molars with deep carious lesions were determined after caries excavation. The teeth were extracted and pulpal status was evaluated after 16 months of microbial control to determine the etiopathogenic role of germs for carious progression in dentine. 67% of the primary molars were free from pulpal inflammations. Soft carious dentine were significantly higher infected than the clinically acceptable hard dentine. Only in 40% of the cavity floors the microorganisms were eliminated. In the infected teeth basophilic microorganisms were found in causality to pulps without inflammations; acidogenic streptococci and lactobacilli were involved in pulpal inflammations. Results indicate that the latter genera of microorganisms are of etiological significance for carious progression in dentine.

Actinomycetales↗
PubMed1988

Muscle PO2 in the initial phase of increased local oxygen demand (rhythmical muscle contraction) in rats with portacaval shunt (PCA).

The influence of a hyperdynamic syndrome caused by PCA on PO2 distribution in skeletal muscle of rats during the initial phase of muscle activity was examined. Rhythmical muscle contraction of the m. biceps femoris was induced by direct electrical stimulation. Tissue PO2 of the contracting muscle was recorded continuously from the start of the 210 s-long activity period up to 140 s after the last contraction using a multiwire surface electrode. In comparison with controls no different behaviour of mean muscle PO2 in the initial phase of contraction was found. After muscle activity mean PO2 decreased to a lower level in rats with PCA than in controls. This might be a further indication of the disturbing influence of a hyperdynamic syndrome on the regulating mechanisms of the microcirculation.

Animals↗
PubMed1988

Circadian course of PO2-oscillations in skeletal muscle of intact and portacaval shunted (PCA) rats.

In rats several circadian rhythms such as heart rate, body temperature, and locomotor activity are known. Several authors found a loss of day-night-rhythm (locomotor activity, EEG) after portacaval shunting (PCA). The aim of this study was to evaluate whether muscle PO2 oscillations are circadian and whether they are altered after time-limited hypercirculation caused by PCA. 126 days after operation tissue PO2 of m. rectus abdominis of 9 rats with PCA and 10 controls was measured with a multi-wire surface electrode. All animals were kept under constant conditions and each animal was measured 6 times at intervals of 4 hours in order to get a circadian PO2 course. In controls the circadian course of mean muscle PO2 resembled a sine oscillation with high values at night and low values in the afternoon. In PCA-rats the time course of mean muscle PO2 showed 3 oscillations with different amplitudes, each with a period length of 24 hours. Our results indicate that oscillations of muscle PO2 are determined principal by circadian locomotor activity and that time-limited hypercirculation influences the circadian course of mean muscle PO2.

Animals↗
PubMed1988

Influence of normovolemic hemodilution with 10% HES 200 on tissue PO2 in the M. tibialis ant. of 7 male volunteers.

The aim of the present study was to investigate the effect of normovolemic hemodilution with a middle molecular HES solution on oxygen supply and PO2 pressure distribution in the extremity muscles of healthy male subjects. In addition to a significant reduction of the hematocrit (Hct) by hemodilution from about 44% to about 37% and unchanged arterial blood gas values, an increase of the mean muscle PO2 from about 16 mmHg (before hemodilution) to about 27 mmHg (30 minutes after having reached normovolemia) was observed. The increase of the mean tissue PO2 is demonstrable already 30 minutes after the start of infusion (t = 30) (see Table 2). The markedly raised level of the tissue PO2 in the M. tibialis anterior as compared with the initial value is demonstrable both during and after normovolemic hemodilution. In addition to this dilution-related increase of the mean tissue PO2, a marked change of configuration of the PO2 histograms is found. There is an increase filling of the PO2 classes in the pressure ranges above 40 mmHg. The conspicuous increase of the intra-individual dispersion of PO2 mean values during and after infusion of HES 200 cannot be interpreted for the moment. Similar observations were, for example, reported by Landgraf and Ehrly in 1985 when measuring the muscular tissue oxygen pressure in patients with intermittent claudication before, after and during infusion of 0.9% saline solution. This could be interpreted as an increased perfusion of certain areas of the muscular capillary system.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗