Showing papers by "University of Gothenburg published in 1977"

Susceptibility of various microorganisms to chlorhexidine.

Abstract: The susceptibility to chlorhexidine of bacteria in aerobic, facultatively anaerobic and anaerobic isolates from clinical specimens of wounds, urine, saliva, and dental plaque was studied. Agar diffusion tests using 50 microng chlorhexidine discs and agar dilution tests were performed and the MIC values correlated with inhibition zone diameters. Anaerobic plaque strains were isolated and tested by the agar dilution method in an anaerobic glove box. Regression lines obtained for five agar media demonstrated a good correlation between zone diameters and MIC values. There was a broad range of susceptibility to chlorhexidine among both Gram-positive and Gram-negative strains. Low MIC values were noted for staphylococci, S. mutans, S. salivarius and E. coli, while strains of Proteus, Pseudomonas and Klebsiella were less susceptible. S. sanguis showed intermediate susceptibility with both low and high MIC values. Among the anaerobic isolates tested, the strains most susceptible to chlorhexidine were Propionibacterium and Selenomonas, While the least susceptible strains were Gram-negative cocci resembling Veillonella.

Periodontal surgery in plaque‐infected dentitions

Abstract: A clinical trial was performed to study the result of periodontal treatment following different modes of periodontal surgery in patients not recalled for maintenance care. The material consisted of 25 patients distributed into 5 groups. Following an initial examination, all patients underwent presurgical treatment including case presentation and instruction in oral hygiene measures. This instruction was given once. The various patient groups were then subjected to one of the following surgical procedures: 1) the apically repositioned flap operation including elimination of bony defects 2) the apically repositioned flap operation including curettage of bony defects but without removal of bone 3) the "Widman flap" technique including elimination of bony defects 4) the "Widman flap" technique including curettage of bony defects but without removal of bone 5) gingivectomy including curettage of bony defects but without removal of bone. Six, 12 and 24 months after completion of the treatment, the patients were recalled for assessment of their oral hygiene standard and periodontal conditions. The results showed that case presentation and oral hygiene instruction given once, only temporarily improved the patient's oral hygiene habits. Renewed accumulation of plaque in the operated areas resulted in recurrence of periodontal disease including a significant further loss of attachment. All five different techniques for surgical pocket elimination were equally ineffective in preventing recurrence of destructive periodontitis.

Determination of a new rapid plasmin inhibitor in human blood by means of a plasmin specific tripeptide substrate

Abstract: A method for determination of antiplasmin activity is presented. Plasmin and plasma are incubated, and the remaining plasmin activity is measured spectrophotometrically by means of the plasmin specific tripeptide substrate H-d-Val-l-Leu-l-Lys-p-nitroanilide. The method is simple, rapid and easily automatized. By the immunoadsorption technique, and with the aid of purified substances it is shown that the measured activity is mainly due to a new antiplasmin [2,4] and possibly to some extent to alpha1-antitrypsin and C1-esterase inhibitor have no antiplasmin activity in the method. Heparin and epsilonaminocaproic acid interfered with the assay.

The effect of orthodontic tilting movements on the periodontal tissues of infected and non‐infected dentitions in dogs

Abstract: The aim of the present investigation was to study (1) whether it was possible, by orthodontic tooth movement, to shift a supragingivally located plaque into a subgingival position, and (2) periodontal tissue reactions around tilted and intruded plaque-infected teeth. The experiments were performed on five dogs which were fed a diet that allowed dental plaque accumulation. The lower third premolars (3P and P3) were extracted and a phase of experimental periodontal breakdown was initiated on day 0. The periodontal pockets around the lower fourth premolars (4P and P4) were eliminated on day 210. During surgery, a notch was prepared in the root at the level of the marginal alveolar bone in order to facilitate measurements in radiographs and histological sections. After 60 days of healing with plaque control, i.e. on day 270, orthodontic appliances producing tipping forces on 4p and P4 were inserted. From day 270 to day 450, plaque was allowed to accumulate on 4P (test = T) while P4 (control = C) was brushed twice daily. The dogs were sacrificed on day 450. Following sacrifice, tissue sections comprising 4P, 1M and P4, M1 were produced and subjected to microscopic analysis. The present investigation showed that it was possible by orthodontic tooth movement to shift a supragingivally located plaque into a subgingival position. The mesial-apical movement of the plaque-infected teeth resulted in the formation of infrabony pockets. In four out of five dogs the displacement of the plaque-infected tooth resulted in an apical shift of the connective tissue attachment. When similar orthodontic forces were acting on plaque-free teeth, the tilting movement did not result in the formation of infrabony pockets. In only two dogs did the treatment result in loss of connective tissue attachment.

Effect of bacterial products on inflammatory reactions in the dental pulp.

Abstract: – Culture filtrates (extracellular components) and material obtained from disintegrated cells (intracellular components) of cultured plaque bacteria were studied for their capacity to induce inflammatory reactions in the dental pulp. Class V cavities were prepared on the buccal surface of 94 teeth: 42 test and 52 control teeth in six adult monkeys. Lyophillzed bacterial components were sealed into the test cavities either alone or following an 8-h topical application of a solution of the same components in phosphate-buffered saline (PBS). Culture medium and PBS were applied in two sets of control cavities. A third set was restored with zinc oxide-eugenol cement. The animals were killed 32 h after the initiation of the experiment and the pulps were examined histologically. Teeth treated with extra- and intracellular components from bacteria elicited marked infiltration of neutrophil leukocytes in the area of the pulp subjacent to the cut dentin tubules. Abscess formation was frequently found. The severe reactions which developed were independent of differences between individual animals and differences in thickness of the remaining dentin. The controls showed damage to the odontoblasts but little or no neutrophil infiltration. The findings confirm that products of bacteria applied to exposed dentin initiate inflammatory reactions in the dental pulp.

Imipramine: clinical effects and pharmacokinetic variability.

Abstract: Sixty-six hospitalized depressed patients were treated for 4 weeks with imipramine (Tofranil®) 225 mg/day. Blood samples were drawn twice weekly 15 h after the last drug intake, and IP and DMI concentrations in plasma were assayed by quantitative in situ thin-layer chromatography. Clinical rating was carried out once weekly by Hamilton's Rating Scale (HRS), Beck's Depression Inventory, WHO Depression Scale (Quantitative Part), and a side-effect scale. The patients were classified on the basis of the WHO Depression Scale (Qualitative Part) as ‘endogenous’ (N=37) or ‘non-endogenous’ depressions (N=29). Antidepressive effect was evaluated on the basis of the posttreatment rating scores. In patients classified as ‘endogenous’ depressions all 12 responding patients (HRS≦7) had plasma levels of IP>45 μg/l and DMI>75 μg/l, whereas 11 out of 14 nonresponding patients (HRS≧16) had plasma levels of one or both compounds below these limits. Ten out of 12 responders had levels of IP+DMI above 240 μg/l, and all nonresponders had levels of IP+DMI below this limit. Patients with partial response (HRS: 8–15) formed an overlapping group. There was no sign of an upper plasma level limit for the antidepressive effect of imipramine. The plasma level/effect relationship was less clear in patients with ‘non-endogenous’ depressions, since several of them responded at low plasma levels. Some relationship between effect on blood pressure (orthostatic effect) and high plasma levels of IP and DMI was found. Using a plasma level limit of IP≷45 μg/l and DMI≷75 μg/l, it was possible to predict the response of the ‘endogenous’ depression group for 10 out of 12 responders and 10 out of 14 nonresponders on the basis of plasma level measurements obtained after 1 week of treatment.

Body fat and adipose tissue cellularity in infants: A longitudinal study☆

Abstract: Body fat, fat cell size, and fat cell number were determined in a longitudinal study on 16 normal-weight infants during the age period 1-18 mo. The methods used included whole-body counting of 40K for determination of body fat and adipose tissue biopsies. A new method of calculation of body fat in infants is presented. No sex differences were found. Body fat expressed as per cent of body weight increased from 16.2% to 28.1%. From 1 to 12 mo of age the expansion of body fat was explained by and increase in fat cell size, while in the age period 12-18 mo it was mainly due to an increase in fat cell number. At 18 mo lthe fat cell size was the same as in 8-yr-old girls and 22-yr-old women (normal-weight females previously studied). The fat cell number at 18 mo, however, was far below the number at 8 yr of age, as well as the still higher number of the 22-yr-old women.

Bite force and oral function in patients with osseointegrated oral implants.

Abstract: The function of the masticatory system was analyzed in 19 patients (13 women and 6 men), aged 39 to 68, randomly selected from a group of 165 patients who had been treated with osseointegrated oral implants within the last 7 years (average 3.5 years). The patients were well satisfied with the functional capacity of their implant reconstructions, especially compared with the poor function before treatment. According to the clinical examination, all but one patient had no or only mild symptoms of dysfunction of the masticatory system. Three bite-force levels were recorded. The mean value for gentle biting was 15.7 N, for biting as when chewing 50.1 N, AND FOR MAXIMAL BITING 144.4 N. The patients could thus well discriminate between the different bite-force levels, and the maximal values are much higher than those in persons with removable dentures.

Frequency selectivity of single auditory‐nerve fibers in response to broadband noise stimuli

Abstract: The tuning of single auditory nerve fibers in the rat in response to broadband noise was studied in a large sound intensity range. Pseudorandom noise was used as stimuli and the cross spectrum between a period histogram of the noise and a period of the noise was used as an approximation of the transfer function from sound to the modulation of the neural discharge rate. In units with a CF higher than 1000 Hz, the width of the cross spectra (at 10‐dB points) invariably increased as the stimulus intensity increased and the center frequency decreased. The few units studied with CF below 1000 Hz seemed to undergo somewhat less of a change in width. The cross correlograms of all fibers with a characteristic frequency (CF) below 5 kHz showed a damped oscillation the duration of which decreased as stimulus intensity was increased. The similarity between the nonlinearity shown here and that shown in measurements of basilar membrane motion using the Mossbauer effect is discussed.

Microbial and salivary conditions in 9- to 12-year-old children.

Abstract: – The prevalence of S. mutans and lactobacilli, the salivary secretion rate, and salivary pH and buffer capacity were examined in 655 children 9–12 years old. Some of these factors were correlated with the frequency of caries. Positive correlations were ob served between for example S. mutans and lactobacilli, between S. mutans and incipient smooth surface caries, and between lactobacilli and open carious lesion. A high proportion of the children showed large numbers of S. mutans and lactobacilli

Airborne micro-organisirns and prevalence of byssinotic symptoms in cotton mills

Abstract: The concentration of airborne microbes, their endotoxins and the prevalence of byssinotic symptoms among workers were measured in the cardrooms of seven cotton spinning, a wool spinning and two cotton waste mills and in a dusty workroom of a group of five willowing mills, a tea-packing plant and a pipe tobacco factory. The concentration of microbes cultured on endoagar plates were found to correlate with byssinosis prevalence (r>0.95, P 0.77, P<0.01) and that of fungi and endotoxins not at all.

Lack of effect of trauma from occlusion on the recurrence of experimental periodontitis.

Abstract: The experiments were performed in 15 dogs fed a diet which allowed dental plaque accumulation. A phase of experimental periodontal breakdown was initiated on day 0. After 210 days five dogs were sacrificed. In the remaining 10 dogs the periodontal pockets around the fourth lower premolars (4P and P4) were eliminated. During surgery a notch was prepared in the root at the level of the marginal termination of the alveolar bone in order to facilitate measurements in histological sections. From day 210 to day 450 the teeth of the animals were brushed twice daily. After 60 days of healing, i.e. on day 270, five of the dogs were sacrificed. Trauma from occlusion of the jiggling type was on day 270 produced in the P4 region of the remaining dogs by the installation of a cap splint and a bar device. The final five dogs were sacrificed on day 450. Following sacrifice, tissue sections comprising 3P, 4P, 1M and P3, P4, M1 were produced and subjected to microscopic analysis. The experiments revealed that, in the dog, forces produced by occlusal trauma are unable to induce a phase of progressive destruction of the periodontal tissues in tooth regions where the supporting tissues are markedly reduced but non-inflammatory.

The effect of a plaque control program on gingivitis and dental caries in schoolchildren.

Abstract: It is well recognized that dental plaque is the main etiologic factor in gingivitis and that carious lesions do not develop in the absence of microbial colonization on tooth surfaces.4 11,12 The preventive effect of successful plaque control programs on gingivitis and periodontitis is generally accepted but it has been questioned whether the development of caries can be avoided or reduced by improved oral hygiene.2 16 Some years ago, a clinical trial was initiated in Swedish school children to study if it was possible to eliminate gingivitis and caries by utilizing a meticulous plaque control program. The trial was carried out in children aged 7 to 14 years. Once every second week during a two-year period, they were recalled to a dental nurse for oral hygiene instructions and professional tooth cleaning with mechanical instruments. During cleaning, a prophylaxis paste was used which contained sodium monofluorophosphate. The clinical reexaminations after one and two years of such preventive care revealed that the children had dramatically improved their oral hygiene, had excellent gingival conditions, and had practically no new caries lesions. The effective plaque control exercised by the children prompted the authors to prolong the interval between the professional prophylaxis. Hence, during the third and fourth years of trial, the same preventive treatment was delivered but less frequently. The present paper reports the effect of the prophylactic program from the entire fouryear period.

A clinical study of the relationship between crowding of teeth, plaque and gingival condition

Abstract: A clinical trial was undertaken to assess whether crowded teeth were more likely to accumulate plaque and develop gingivitis than non-crowded teeth. A tooth was considered crowded if it was displaced by 2 mm and/or rotated 15 degrees or more from the normal position in the arch. The material consisted of 50 dental students aged 21 to 32 years. An initial examination comprised assessment of Plaque Index, Gingival Index and pocket depths. After this examination the subjects refrained from using interdental cleaning aids but continued with their normal toothbrushing for 40 days. After re-examination they were instructed in the effective use of dental floss. A final examination was carried out after 140 days. At the start of the trial no difference was found in regard to the Plaque Index between crowded and non-crowded teeth. The Gingival Index for growded front teeth, but not for crowded premolars, was somewhat higher than for the corresponding controls. The cessation of interdental cleaning resulted in a similar increase in plaque accumulation and gingival inflammation in both non-crowded and crowded teeth. The use of dental floss for approximal tooth cleaning resulted in a similar decrease in the Plaque- and Gingival Indices for both types of teeth. The results demonstrate that in a group of young adults, crowding of teeth (1) did not favour plaque accumulation on approximal tooth surfaces and (2) influenced the degree of gingival inflammation only to a minor extent.

A theoretical framework for the description of estuaries

Abstract: A theoretical framework for the description of an estuarine system is outlined, with particular reference to the Baltic. This description, in terms of continuous functions of salinity and time, may be considered as an improvement of existing “box models”, which are inherently incapable of making efficient use of hydrographic data. Relations between deep water supply and internal mixing properties, as well as the equations controlling diffusion of substances in general, are derived and their applicability discussed. DOI: 10.1111/j.2153-3490.1977.tb00716.x

Constancy of clinical signs in patients with mandibular dysfunction.

Abstract: Repeated clinical examinations were performed 6 weeks apart on 34 patients with mandibular dysfunction to estimate the consistancy of clinical signs. The clinical examination of the patients included the masticatory muscles, the temporomandibular joint (TMJ) and the mandibular movement capacity. The clinical dysfunction index (Di) was calculated as a measure of the degree of mandibular dysfunction. The highest agreement between examinations was found for maximal mouth opening and protrusion. The agreement for palpation tenderness of the masticatory muscles and TMJ, limited movement of the TMJ, TMJ sounds, and pain during movement was considerably lower. The lowest agreement within 6 weeks was found for the clinical dysfunction index. No statistically significant difference could be detected between the two examinations for any of the clinical signs, as a result of given information and counseling before the 6-week period. It was concluded that all clinical signs, except maximal mouth opening and maximal protrusion, showed low consistancy.

Physical training in human hyperplastic obesity. IV. Effects on the hormonal status

Abstract: Severely obese subjects and sex- and age-matched controls underwent physical training during a 6-wk period. Evidence of training was shown in all subjects by increased aerobic power. Before training the obese subjects were characterized by the following abberations: decreased glucose tolerance, hyperinsulinemia, elevated blood glycerol and plasma free fatty acids, and a blunted plasma growth hormone response during glucose tolerance. Noradrenaline output was elevated, a finding of potential interest for the explanation of increased lipolysis, blood pressure, and heart size in obesity. With training the following changes were found: In the controls there was evidence for the beginning of a decrease of adipose tissue mass. In the obese, however, body weight, body fat, or fat cell size did not decrease during training. Plasma insulin decreased, and a corresponding increase of plasma glycerol was seen. Glucose tolerance was not changed, and this, together with decreased plasma insulin, indicated an increase insulin sensitivity of the periphery. Changes in noradrenaline or growth hormone during training could not explain this increased sensitivity. Urinary cortisol output was found to decrease after training in the obese; this might be interpreted as a decrease in cortisol secretion allowing a more effective insulin action on the periphery.

Steady-state kinetics of imipramine in patients.

Abstract: Steady-state plasma level kinetics were studied in 76 patients given imipramine (IP) 150 to 225 mg/day for 2–5 weeks. IP was given in three divided doses at 8.00 a.m., 1.00 p.m. and 5.00 p.m. Plasma concentrations of IP and its active metabolite desipramine (DMI) were determined by quantitative in situ thin-layer chromatography. The plasma levels of IP and DMI showed pronounced flucutations throughout the day with a ratio of about 2 between highest and lowest level. Patients with steady-state levels of IP and/or DMI below 50 μg/l reached this within 1 week of treatment. Patients with higher steady-state levels reached steady-state concentrations within 2–3 weeks. There were some intraindividual fluctuations in plasma levels from week to week after steady state had been reached (coefficient of variation: 10–20%). Interindividually, the steady-state levels corrected to a dose of 3.5 mg/kg per day varied considerably: IP: 6–356 μg/l, DMI: 24–659 μg/l and IP+DMI: 58–809 μg/l. The steady-state plasma levels showed a skew distribution that became normal by logarithmic transformation. The IP/DMI ratio ranged from 0.07 to 5.5 with a median value of 0.47. Compared to data from amitriptyline treated patients the IP/DMI ratios had significantly lower median value and larger variation than the corresponding plasma level ratios of amitriptyline/nortriptyline. Several statistically significant differences in steady-state levels between age groups were found. For IP: Women aged 30–39 had lower levels than women aged 20–29, 40–49, and 50–59, and men aged 50–59 and 60–65; men aged 30–39 had lower levels than men aged 60–65. For DMI: Women aged 30–39 had lower levels than women aged 50–59.

Biofeedback in the treatment of long-term temporomandibular joint pain: an outcome study.

Abstract: Eleven patients with long-term pain related to the temporomandibular joint (TMJ) were trained in tension awareness and relaxation using feedback of muscle tension level in the masseter through a digital display. At a follow-up examination 4–15 months after the termination of treatment, 8 of the 11 patients were totally symptom-free or significantly better; 1 patient was slightly better, and there was no effect for 2 patients. Possible reasons for failure and sex differences are discussed.

Cleptoparasitism and odor mimetism in bees: do nomada males imitate the odor of andrena females?

Abstract: Identical chemical compounds are present in the Dufour gland secretion of female Andrena bees and in the cephalic secretion of many male Nomada bees. Females of Nomada parasitize the nests of Andrena. Many Nomada species confine their attacks to a single host species. In two such host-parasite pairs, Andrena haemorrhoa-Nomada bifida and Andrena carantonica-Nomada marshamella, all-trans farnesyl hexanoate was found to be the totally dominant component in respective secretions. In two other pairs, Andrena helvola-Nomada panzeri and Andrena clarkella-Nomada leucophthalma, geranyl octanoate is the major component. This pairwise odor correspondence is discussed in relation to critical points of contact in the life cycles of host and parasite, male and female.

The demethylation of imipramine and clomipramine as apparent from their plasma kinetics

Abstract: The demetylation of imipramine and clomipramine was studied after administration by different routes of single doses of clomipramine hydrochloride and multiple doses of clomipramine as well as imipramine hydrochloride. Five healthy volunteers received 1 mg of clomipramine hydrochloride/kg body weight as single oral and intramuscular doses on different occasions for the purpose of studying the plasma levels of clomipramine and the desmethylclomipramine formed. Desmethyl-clomipramine was found in the plasma in four of the subjects after oral intake but only in one subject after intramuscular injection. The peak levles of clomipramine were considerably higher after intramuscular than after oral administration. The half-lives of clomipramine after oral administration ranged from 11.6–35.8 h $$\bar M = 20.8 \pm 4.0$$ and after intramuscular administration from 20.1–39.6 h $$\bar M = 24.7 \pm 3.7$$ . Twenty subjects received either imipramine or clomipramine both orally and intramuscularly during a period of 3 weeks in a crossover design. The plasma levels of imipramine and clomipramine and their demethylated metabolites desipramine and desmethyl-clomipramine were determined during the treatment. The ratio between the plasma level of the parent drug and its demethylated metabolite was on average twice as high during intramuscular as during oral treatment.

Volatile marking secretions from the labial gland of north European pyrobombus D. T. males (Hymenoptera, Apidae)

Abstract: The volatile secretions produced by the labial gland in male bumble-bees,Bombus Latr., belonging to the subgenusPyrobombus D. T., have been studied in six species:B. cingulatus Wahlb.,B. hypnorum L.,B. jonellus K.,B. pratorum L.,B. lapponicus Fabr. andB. scandinavicus Friese. Totally, 181 specimens have been analyzed. The secretions, which are used for marking different objects along the flight-route, have been analyzed by capillary gas chromatography and combined capillary gas chromatography/mass spectrometry. Isoprenoids and fatty acid derivates together make up the secretions. The former group of compounds dominates the marking secretions from the species studied, with the exception ofB. scandinavicus. The compositions of the secretions are characteristic for each species.

Clinical findings in temporomandibular joint osteoarthrosis

Abstract: – The clinical findings in 20 patients with TMJ-crepitation (E1-group) and 19 patients with TMJ palpatory tenderness (E2-group) have been compared with the findings in 29 other patients with mandibular dysfunction (R-group). The patients underwent a clinical examination of the masticator system and of the second distal interphalangeal joints (DIP II joints). No statistically significant differences could be found between groups with respect to clinical signs, occlusal interferences, or dental attrition. Loss of molar support was found to be significantly more frequent in the E1-group than in the R-group. The frequency of tenderness to palpation or pain on movement of DIP II joints was significantly higher in the E2-group than in the R-group. Periarticular bony swelling of DIP II joints was significantly correlated with TMJ-crepitation. The patients with TMJ-crepitation were considered to have TMJ-osteoarthrosis. The results of the present study indicate that patients with TMJ-OA have a similar clinical picture to other patients with mandibular dysfunction and that molar loss plays a role in the etiology of TMJ-OA.

Recording of mandibular movements by intraorally placed light emitting diodes.

Abstract: In order to evaluate an opto-electronic system for recording mandibular movement a simulator and clinical pilot study was performed. The method was based on light emitting diodes (LED) and a photodetector system. One LED was placed intraorally and one on the forehead, the latter acting as reference. When the light spot is focused on the detector surface a photo-current will occur. This current can be used to obtain two signals linearly related to the x and y coordinates of the LED. By using two detectors the three-dimensional coordinates of a movement can be calculated, consequently also the z-coordinate. In the simulator experiment the method was shown to have a satisfactory precision and good reproducibility. The results from the clinical test indicated that it is possible to measure and record mandibular movement with a minimum of external influence to the test person.