Leukocyte density and volume in normal subjects and in patients with acute lymphoblastic leukemia.

A method is described for the separation of blood and bone marrow leukocytes on the basis of buoyant density, using a discontinuous Ficoll-Hypaque density gradient. The median cell densities of monocytes and lymphocytes were found to be 1.067-1.077 and 1.073-1.077 g/ml, respectively. The cells of the myeloid series were shown to increase in density with maturation; the myeloblasts had the lowest density (1.064-1.065 g/ml) and the neutrophils the highest (greater than 1.080 g/ml). Cell volumes have been determined on isolated cell populations. The findings were: monocytes, 534 +/- 47 cu mu; lymphocytes, 247 +/- 18 cu mu; and neutrophils, 468 +/- 24 cu mu. Fourteen patients with acute lymphoblastic leukemia were studied. In four patients, the lymphoblasts were of low density (less than 1.068 g/ml), whereas the remaining patients had high density (greater than 1.068 g/ml) lymphoblasts. These four patients had large numbers of lymphoblasts in the peripheral blood and a poor prognosis. Lymphoblast volumes were not different in these two groups and were unrelated to prognosis.


Regulation of bone marrow cell growth in diffusion chambers: the effect of adding normal and leukemic (CML) polymorphonuclear granulocytes.

Inhibition of granulopoiesis was studied using the diffusion chamber (DC) technique. When mature granulocytes from human blood or syngeneic mouse peritoneal fluid were added to mouse bone marrow cells cultured in DC, a significant depression of granulopoiesis took place, and a stimulation of macrophage formation was observed in 7-day cultures. Human granulocytes had a stronger inhinitory capacity than mouse granulocytes. The inhibition appeared to be tissue-specific and caused by a diffusible factor. A time study showed that the added granulocytes had no observable effect on the growth of proliferative granulocytes and CFU-C during the first days of culture. A rapid decrease of proliferative granulocytes after day 5 was preceded by a similar reduction of CFU-C 1 day earlier. The effect of CFU-S was more variable. In one strain of mice, there was a consistent increase in the granulocyte co-culture group, whereas in another strain a significant increase was observed only on day 2. Hislotologic examination showed that mature granulocytes changed the colony distribution, so that a significant relative decrease of granuloid colonies occurred. The nature of this delayed suppression of granulopoiesis is not evident from these data. A possible explanation is that factors released by mature granulocytes prevent recruitment of CFU-C and granulocyte precursors from the CFU-S compartment by blocking the granulopoietic pathway. Leukemic (CML) granulocytes isolated from blood were less able to inhibit granulopoiesis than normal granulocytes with mouse bone marrow as well as human bone marrow as target cells.


Hodgkin's disease and myelomonocytic leukemia: an ultrastructural and immunocytochemical study.

The ultrastructual and immunologic features of the initial Reed-Sternberg and Hodgkin cells are compared with the ultimate leukemic cell type in a child with Hodgkin's disease who subsequently developed acute myelomonocytic leukemia (AMML) following 29 months of chemotherapy. Hodgkin tumor cells contained cytoplasmic IgG and ultrastructurally resembled large immunoblasts, containing one or two round nuclei with large bizarre nucleoli, many polyribosomes, sparase endoplasmic reticulum, underdeveloped Golgi lamellae, and few cytoplasmic granules. The Hodgkin tumor cells displayed no evidence of phagocytosis. The leukemic monocytic cells did not contain cytoplasmic IgG and, ultrastrucally, exhibited and indented and irregular nuclear profile with less prominent nucleoli, numerous pleomorphic granules, a moderate number of free ribosomes, short segments of endoplasmic reticulum, and stacked Golgi lamellae. The cell surface was irregular and occasionally appeared involved in endocytic activity. These results indicate that the Hodgkin tumor cells originated from B lymphocytes rather than tissue macrophages, whereas the leukemic monocytes arose from the bone marrow-derived monocyte-macrophage series. The findings suggest further that AMML developing after Hodgkin's disease consitutes a second neoplasm rather than a leukemic transformation of Hodgkin tumor cells.


Thymoma and chronic myelogenous leukemia: a case report.

A case of epithelial thymoma occurring synchronously with Philadelphia chromosome-positive chronic myelogenous leukemia and urinary bladder carcinoma in a 76-year-old man is described. Thymomas have been associated with numberous hematologic, collagen-vascular and autoimmune disease states, as well as with an increased incidence of nonthymic malignancy. Human thymoma-associated leukemia is, however, extremely unusual, despite the well-documented role of the thymus in leukemogenesis in experimental animals. No previous literature reports of thymoma associated with chronic myelogeneous leukemia were found. A review of long-term followup data of surviving thymoma patients is necessary to determine if an increased propensity to develop leukemia is present in present in patients with thymoma.


Enhancement of drug cytotoxicity by recruitment of leukemic myeloblasts with humoral stimulation.

To demonstrate that the effect of 1-beta-D-arabinofuranosylcytosine can be increased when the leukemic cell growth fraction is augmented by induced humoral factors, bone marrow cells from 14 patients with acute myeloblastic leukemia were studied in vitro. Cells were cultured in either pooled stimulatory serum, obtained from leukemic patients undergoing chemotherapy, or autologous leukemic pre-treatment serum. After 2 days in culture, serum containing 1-beta-D-arabinofuranosylcytosine was added. Cells cultured in stimulatory serum proliferated markedly when compared with cells cultured in pretreatment serum, as measured by tritiated thymidine incorporation into an acid-insoluble precipitate, tritiated thymidine labeling indices, and viable tumor cell counts. The cytotoxic effect of 1-beta-D-arabinofuranosylcytosine was enhanced in those cells initially cultured in stimulatory serum relative to cells initially cultured in pretreatment serum. These studies are consistent with the hypothesis that induced humoral stimulation of acute myeloblastic leukemic cells in vitro recruits a greater tumor growth fraction and thereby increases the cytotoxicity of cycle-dependent drugs.


Radiation-induced murine leukemia ERLD in cell culture.

The lymphoblastic leukemia ERLD, induced by radiation in a C57BL/6 mouse, was established in culture. Three cell lines, ERLD/Y3, ERLD/T ERLD/Two, have been in culture for nearly three years. Their isolation and growth depended upon the presence of 2-mercaptoethanol, glutamine, and asparagine in the medium. The cell lines, except ERLD/T, possess the TL antigen, a characteristic of ERLD and of other murine leukemia cells in vivo and of normal thymus cells of certain mouse strains, but not of C57BL/6. A distinctive submetacentric marker chromosome is also common to ERLD and the derived cell lines. The successful establishment of ERLD in culture provides a malignant thymocyte-related cell system for studies in nutrition and immunobiology.


A survey of the dental needs of hospital inpatients in Scotland.

Eight hundred and ninety-four inpatients in four hospitals in Edinburgh were assta were used to estimate future inpatients' dental requirements and the hospital dental services which would be necessary to meet these needs. Seventeen percent of the sample was found to be suffering from pain or discomfort of dental origin and over 30% were considered to require some form of dental treatment before their expected date of inpatient discharge.


Plaque-removing effect of dental floss and toothpicks in children 12-13 years of age.

The aim of the present study was to assess the cleaning effect of dental floss and toothpicks on interproximal surfaces. The plaque situation was assessed in a group of children 12-13 years of age by the Patient Hygiene Performance Index (PHPI). It was found that dental floss has a greater plaque-removing effect of the interproximal areas than toothpicks, predominantly on the mesial surfaces of the teeth.


A comparison between the release of fluoride from sodium fluoride lozenges and bone meal tablets.

The release of fluoride from a fluoride-containing bone meal tablet and a chewable sodium fluoride lozenge to 0.5 M perchloric acid, deionized water, and saliva was compared. In acid, all the fluoride was released from the bone meal tablet (0.25 mg F), while there was a poor release in water and saliva (2-10 %). The release from the sodium fluoride lozenge (0.25 mg F) was essentially complete in water and saliva as well as in acid. Following sucking and chewing on a sodium fluoride lozenge, the mean salivary fluoride concentration increased from 0.04 to 36 parts/10(6) 5 min after intake. Concentrations exceeding the preintake level were still recorded after 20 min. With the bone meal tablet, only a slight increase (to 0.2 parts/10(6)) in the salivary fluoride level was obtained.


Effect on caries of self-application of a zirconium silicate paste containing 9% stannous fluoride.

A 2-year clinical trial was conducted using an adolescent population from a low-fluoride area to evaluate the anticaries effect of self-applications of zirconium silicate paste containing 9% stannous fluoride. tthree study groups totaling 464 children, with an initial average of 12.8 years, completed the study. The control group brushed with a non-fluoride zirconium silicate paste (tzircate Prophylaxis Paste) once each year: the first experimental group brushed with zirconium silicate paste containing 9% stannous fluoride (Zircate Treatment Paste) once each year; and the second experimental group brushed every 6 months with Zircate Treatment Paste. After 2 year, the DMFT and DMFS increments were virtually identical for the control group and the group that received one application of fluoride paste per year. The group that received two applications of fluoride paste per year had a DMTF increment that was about 24% less than that of the control group; however, the DMFS increment was only 5% less. These differences were not statistically significant at the P=.05 level.


A survey of traumatized primary anterior teeth in Jerusalem preschool children.

The prevalence of traumatized primary anterior teeth was studied in 965 5-year-olds attending compulsory kindergartens in West Jerusalem in 1971. The prevalence of children with traumatized teeth was 11.1%. No difference between males and females was found. In most cases only one tooth was affected. The tooth most frequently affected was the maxillary central incisor. The most common type of fracture was that of enamel with or without dentin.


Patterns of occlusion in 3-year-old Danish children.

Occlusion and spacing patterns are described for 1,624 3-year-old children living in Gladsaxe, a suburb of Copenhagen. Normal transversal relations were found in 1,396 children, while 214 had crossbite, and 14 had scissors-bite. The sagittal and vertical occlusion were significantly different in the three groups. The sagittal occlusion characters were to a large extent identical in the second primary molar, the canine and the incisor regions in the individual child. Open bite was much more frequent in children with maxillary overjet greater than 4 mm than in children with maxillary overjet greater than or equal to 4 mm. Definite mandibular overjet was diagnosed in three children but 19 had a tendency towards mandibular overjet. The number of dummy suckers was very high and significantly higher among children with crossbite than amoung children with normal transversal relations. Crowding was found in the incisor regions, but very seldom, while total spacing existed in 34.5% of the maxillary and 24.3% of the mandibular arches.


Recurrent aphthous ulcerations in a mixed Arab community.

Twenty thousand Arabs of various nationalities living in Kuwait have been investigated over the past 5 years; 5,470 (27%) manifested recurrent aphthous ulcerations (RAU). Non-Kuwaiti Arabs were affected more the Kuwaitis and the prevalence of the disease was respectively 35% and 18%. Among Kuwaitis, only 5% of the Bedouins manifested the diseases whereas 22% of urbanized Arabs were affected. The ratio of the affected females to males in this study was 6:5. The clinical course of RAU in Arabs was similar to that reported in other populations. Various environmental factors such as stressful conditions, social tradition and obligations, and the allergenic Arabic food seemed to affect the prevalence of RAU in different Arab communities.


Occurrence of oral sebaceous glands in 43,654 industrial workers of Gujarat, India.

In 10 cancer patients platelet concentration, platelet consumption, platelet half-life time and plasma concentration of platelet factor 4 were determined. A high frequency of thrombocytosis and increased platelet consumption were observed, and the plasma concentration of platelet factor 4 was increased. However, no significant correlation was found between platelet consumption and the result of a single determination of platelet factor 4 concentrations in plasma.


A study of endogenous dopamine metabolism in Gilles de la Tourette's disease.

This longitudinal, blind study of Gilles de la Tourette's disease in a 44 year old male patient who was nonresponsive to Haloperidol therapy indicates that dopamine excretion is related to clinical response. An increased urinary excretion of dopamine and some of its metabolites was associated with the failure of Haloperidol therapy. Imipramine, administered to treat the patients' depressive mood that emerged in the course of treatment, decreased the urinary excretion of dopamine and moderately alleviated the symptoms of Tourette's syndrome. The results suggest that monitering urinary dopamine and 3-methoxytyramine excretion in Tourette's disease may predict the clinical response to pharmacotherapy, and that a dopaminergic mechanism may be associated with this type of motor hyperkinesia.


[Hygiene in dental practice-- wish and reality].

Theoretical findings on sterilization and disinfection measures are useless for the dental practice if their efficiency is put into question due to insufficient consideration of the special conditions of dental treatment. By data collected in dental offices of various structures, an attempt is made to draw conclusions regarding the methods usually applied. The findings facilitate the search of methods for rationalizing hygienic measures and the organization of such measures.


[Foundations of the neurophysiology of the masticatory organ].

The most important research findings in the field of neuro-physiology of the masticatory system are described, e.g. the clinico-neurological aspects of the swallowing reflex, cortical and subcortical control systems interfering with mastication and especially the two masticatory reflexes taking place at the level of the brain stem, the jaw-opening reflex and the jaw-jerk reflex. A short neuro-anatomic and electrophysiological description of the nucl. tractus mesencephalici, the nucl. supratrigeminalis and the dental pressosensors completes this survey. It concludes with a discussion of possible pathological reflex circles in the pathogenesis of myorthropathies.


[The retention of plastic filling materials with various lining materials and technics].

In "tensile strength" tests an attempt was made to find out whether a material and/or the type of preparation of the cement base and/or a specific filling technique have any influence on the retention of a permanent filling in a cavity prepared according to Black's principles of preparation. The following was found: 1. Amalgam fillings placed on hardened cement bases did not show any differences in their retention behavior. The type of the protective base material was of no importance. 2. Fillings rapidly inserted according to Robiczek's method showed considerably higher retention values. 3. The filling material combines with the cement base only in rapidly inserted fillings which considerably contributes to increased retention.


[Comparative cinematographic studies of the mandibular movements normal subjects and patients with dysgnatias].

Mandibular movements of test persons with eugnathic and dysgnathic dentitions were compared with each other by kinematographic tests and evaluation of single photographs. No essential differences in coarse movements are discernible.  Neither form nor extent of the masticatory movements are significantly influenced by any dysgnathia or the type of food chewed. The testing method applied does not furnish any information on movements in the occlusion phase.


[Diagnostic and therapeutic aspects of myeloma from the point of view of the dentist and the oral surgeon].

Data on 10 patients with myelomatosis from three different maxillo-facial surgery departments are compiled and case histories, clinical courses, radiographs and therapies are studied. The data are compared with 51 cases reported in the literature. The main emphasis of the studies was on: 1. Diagnosis on the basis of the first symptoms in the maxillary region. 2. Prophylaxis and therapy of oral complications.


[Studies on the pharmacodynamics and compatibility of the local anesthetic carticain].

Two local anesthetics were compared with a placebo with regard to subjective tolerance and influence on driving capacity in a double blind test in eight male probands. Neither performance, the ability to respond, reactivity, nor fine motor coordination were reduced or impaired five to sixty minutes after a submucous injection of 3.6 ml of the local anesthetics tested. There were no changes of self-evaluation in the sense of a changed active-passive polarity.


[Fluoridation measures].

Dental caries has become an ever-increasing, important socio-medical and economic problem over the past few years and decades. It is the most widespread of all diseases. If we really want to cope with it and effectively reduce the incidence of this disease, dentists and the authorities bearing the cost of dental therapy must change their attitudes, for it is absolutely necessary that the main emphasis of dentistry be shifted from the still prevailing attitude of simple treatment to a program of prevention. The various methods of fluoride application provide safe, effective, and practical methods of caries prevention.


[Tooth exfoliation in the supporting area, a critical phase in the development of the dentition].

The lateral supporting area should measure at least 22 mm on the average. This value should be corroborated by the use of any available radiographs and consideration of the width of permanent teeth that have already erupted, and sex-specific differences. All means for retaining teeth should be used to prevent a premature collapse of the supporting area.


[Conservative treatment of deciduous teeth--a review].

In all countries with a lack of manpower in dentistry, there is an unfortunate tendency to leave the primary teeth without proper conservative treatment. In addition to toothaches and poor esthetics, a neglected care of the primary dentition may result in several other untoward effects. Decayed deciduous teeth may cause such a discomfort during tooth-brushing that the child is prevented from learning good oral hygiene habits. With bad primary molars the child cannot chew properly, and may have to choose soft and often cariogenic food. When the permanent teeth erupt among the decayed deciduous teeth, there will be a greater chance for them to have carious attacks as well. Premature loss of primary molars may lead to malocclusion. It must also be kept in mind that the treatment of badly decayed teeth, including necessary extractions, may be difficult. This may cause fear of dental treatment. On the basis of current Swedish philosophies of treatment the author surveys various conservative procedures for deciduous teeth-amalgam therapy, stainless steel crowns, composites and disking.


[Restoration of deciduous teeth].

Efficient filling techniques using composite resins, adhesive composite resins after acid etching, and amalgam are discussed especially in view of the expedient use of auxiliary means and pulp-protecting measures.


[Light microscopic presentation of the morphological behavior of the nerves of deciduous teeth during tooth exfoliation deciduous and after loss of the dentition].

Structural changes in the nerve can hardly be demonstrated in nerve sections located intradentally, i.e. away from the area of tooth resorption. pseudohypersegmentation, however, is found intradentally in nerve sections of the radical pulp close to the resorption area. Serious lesions of the nervous substance are found extradentally, in the direct neighborhood of the erupting permanent tooth. If the deciduous tooth was lost more than 12 months ago, intraosseously the final stage of physiological degeneration is reached.


[Special technics for the enlargement of the vestibulum].

From a technical viewpoint, vestibuloplasty is the easiest method to deepen the vestibulum and is mostly preceded by gingivectomy or a flap operation. Grafting of free mucosa is the method of choice in cases of small regions of operation, prominent alveolar ridges, where open vestibuloplasty has already been performed and serious coronal shifting the scar has occurred, and where a coronal sliding of flap was planned as a second operation to cover a gingival recession. In cases of gingival recessions and areas with narrow, less than 3 mm broad gingiva propria having no obvious pathologically altered gingival sulcus, the method according to Edlan and Mejchar is offering the best results.


Human granulocyte phosphoglycerate kinase. Purification by double affinity elution and immunological study.

Human phosphoglycerate kinase has been totally purified from leukemic granulocytes by double 'affinity elution' with ATP and 3-phosphoglycerate. This purification procedure allowed to obtain 19 mg of protein, specific activity of which was 400 IU/mg i.e. a 105-fold purification and an overall yield of 47%. Purified enzyme was homogenous when tested by acrylamide sodium dodecyl sulfate electrophoresis and immunodiffusion. Specific antibodies raised in rabbits totally inactivated phosphoglycerate kinase of crude extracts as well as of the purified preparation. The molecular specific activity (i.e. the ratio enzyme activity/immunological reactivity) was identical in leukocytes, platelets, erythrocytes and was identical in these cells to the value found for the totally purified phosphoglycerate kinase.


The effect of an anabolic agent on N deposition, growth, and slaughter quality in growing castrated male pigs.

The conversion of feed protein into body protein in growing pigs is rather unfavourable. With Dutch Landrace pigs only 30--40 percent of the digestible crude protein is converted into body protein. To study the influence of implanting 20 mg 17beta-estradiol + 140 mg trenbolone acetate per animal on this conversion ratio, three nitrogen-balance experiments were performed with castrated male pigs of 55--75 kg liveweight. In experiment 3 the energy balance was also measured. N-retention was significantly improved by the treatment. In none of the experiments the digestibility of the ration was influenced. With the pigs implanted at around 55 kg live weight, N-deposition during the period from 6--9 till 26--32 days after treatment was increased by on an average respectively of 24 percent (experiment 1), 60 percent (experiment 2) and 56 percent (experiment 3) as compared with a placebo. Where pigs of 75 kg were implanted, N-deposition was increased over the period from 2 till 28 days after implantation by 39 percent as compared with a placebo. In experiment 3 it was shown that the conversion of the metabolizable energy of the ration into energy deposited in the body (= protein + fat) was not considerably altered at 13--17 days after the treatment of pigs (weighing 55 kg) with anabolic agents. As compared with the placebo, N-deposition was increased by 40 percent and fat deposition was descreased by 15--20 percent. So the implantation with the anabolic agents has resulted in shift to a higher protein deposition and a lower fat deposition. The results of the balance determinations were confirmed in a comparative growth experiment, in which 14 castrated male Large Wht& x Landrace pigs of 56 kg weight (i.e. 69 days before slaughter at 90 kg live weight) were implanted with the aforementioned combination; 14 animals served as control. In the period from treatment till slaughter live weight gain was significantly improved by 6.5 kg; feed conversion was 0.3 units significantly lower than the control. Carcass weight was significantly higher for the treated group (difference compared with control 4.5 kg). Carcass quality was also improved; the carcasses of the treated pigs were longer and the thickness of the backfat was less. In a second comparative experiment on growth of castrated male pigs from 66 to 100 kg, the effect of the oral application of the combination ethinylestradiol (0.6 ppm, 1.2 ppm, and 2 ppm respectively in the feed) and trenbolone acetate (2 ppm in the feed) was studied. The three experimental groups and the control group consisted of 15 animals each. Live weight gain was significantly improved in the two groups with the higher levels of ethinyl estradiol (i.e. 4.4 kg and 6.9 kg respectively), feed conversion was significantly lower in all three anabolic agroups (i.e. 0.2, 0.3 and 0.4 respectively). Backfat thickness was less in all three anabolic groups and the carcasses were longer in the two higher dosage groups compared with the control group...


Quality of the meat after the application of anabolic agents in young calves.

Experiments were carried out to test the effect of implantation of Implix¿ (20 mg estradiol + 200 mg testosterone) or Revalor¿ (140 mg trienbolone acetate + 20 mg estradiol) on growth, feed conversion, slaughter quality, and residue levels in black Friesian bull calves at 4, 8, or 4 and 8 weeks before slaughtering. Weighings and calculations of feed conversion were carried out weekly. The control group of weight gain and feed conversion consisted of 22 calves; the chemical analyses of the control group was restricted to 8 animals. Implantation of the hormones at 4 or 8 weeks before slaughtering resulted in a significant beneficial effect on weight gain, feed conversion and carcass index over the control. This effect was improved (up to 15%) by implanting the hormones at 8 and 4 weeks before slaughter. The effects obtained with Revalor seemed to be superior to those obtained with Implix. In 75% of the treated animals, some remainder of implants was found. No effect was found on water binding capacity and colour of raw meat. Carcass quality was not significantly improved as judged from water, fat, ash, and protein content of the M. Longissimus Dorsi. The collagen content of the animals treated with Revalor was slightly, though not significantly, increased. There is a slight decrease in the relative bone content of the treated animals over the control resulting in higher meat percentages. Residues were determined in meat obtained from rib and neck by biological and chemical methods. Oestrogenic activity was found in only 7 samples from the neck; all samples from the rib were negative. Chemical examination indicates the presence of oestradiol in these samples. No residues of trienbolone could be detected in the meat samples. The Pars Dissiminata of the prostate was examined histologically on frozen and paraffin sections. Although the latter permitted a sharper interpretation, both methods indicated an increased activity of the prostates induced by hormone treatment. Compared to Implix, Revalor treatment provoked a more pronounced mucous activity. In recent years, the administration of estrogens in combination with testosterone or with trenbolone acetate (androst-4,9[10]-11-trien-3-one 17-acetate)2,3,4,17 has been shown to improve the growth rate and feed conversion5,14,17 in farm animals. However, there is a lack of information on carcass quality, which is of interest to the producer as well as to the consumer. Moreover, there are sample data14 about the residue levels remaining in the carcass following hormone implantation. These experiments were carried out to test the effect of the implantation of Implix¿ (20 mg estradiol + 200 mg testosterone) or Revalor¿ (140 mg trienbolone acetate + 20 mg estradiol) on growth, feed conversion, slaughter quality, and residue levels in black Friesian bull calves.


[Influence of anabolic agents on behavior].

Sexual steroids are involved not only in the triggering of sexual activity but also in sex-linked social behaviour (aggressiveness etc.) The use of anabolic agents (particularly steroids) raises the problem of their possible interference with these mechanisms. In the normal male, an injection of androgen does not alter the level of sexual activity, which seems to be determined by nervous mechanisms. On the contrary, by feed-back in the hypothalamo-hypophysial mechanisms it exerts a depressive effect on the endogenous secretion. Female hormones have an inhibiting effect which works both by reducing the actual secretion of androgen and by direct action at two levels: the nervous receptors and the target organs of the genital apparatus. In the female, injections of exogenous hormones may interfere with the mechanisms regulating the oestrous cycle, e.g. inhibition of oestrous and of ovulation by progestagens, and luteotrophic or luteolytic action in the case of the estrogens. In an ovariectomized female the injection of testosterone propionate causes the appearance of sexual receptivity. The behaviour induced in this way is completely normal and free from any abnormal male component. The importance of this action has led to the presumption of a role played by the androgens in the normal triggering off of female sexual behaviour. It therefore seems that the nervous system of the female, but not of the male, possesses a potential bisexuality. The rate at which the hormone passes into the circulation appears to be more important than the actual type of hormone (estrogen or androgen) in causing the appearance in the female of sexual behaviour of one or the other sex. It has been suggested that estrogens might be the active steroid form necessary at the nervous structure level for initiating sexual behaviour in the two sexes, while the androgens would have to undergo aromatization in order to acquire their effectiveness at that level. Aggressiveness depends on the sexual hormones; the androgens are normally responsible for the high level of aggressiveness in males. On the other hand, in some species the characteristic aggressiveness of the female is explained by the presence of progesterone (e.g. hamsters). The territorial marking typical of the male of, for example, the dog, cat and rabbit species etc. is also due to the androgens. The pheromones usually depend on the sexual hormones (pheromones of sexual attraction which promote or inhibit aggression, etc.) A "sexualization" of the nervous system exists---e.g. of the hypothalamus---which is refelcted not only in the modes of hypophysial secretion but also in the type of sexual behaviour. This sexualization occurs through the loss of the possibility of a female-type reaction that occurs in the male under the influence of the androgenic secretions of the foetal or neonatal testicle. Therefore this action appears at an early stage and is conclusive...


Occurrence of anabolic agents in plants and their importance.

More than 40 plant species have been shown to contain substances that are active in biological assays for estrogenic activity. Such substances may be constitutive metabolic products of a plant, or be formed adaptively in response to environmental factors, such as fungal attack (e.g. coumestrol synthesis in alfalfa infected with Pseudopeziza medicagensis); in other instances estrogens may arise from microbial attack on plant material during storage (e.g. zearalenone formation from corn by Fusarium spp.) Phyto-estrogens may reach man through direct consumption of fresh fruit, vegetables and processed plant products (e.g. administration of olive or cornoil can induce vaginal keratinization in post-menopausal women); or---more relevant to this Symposium---by consumption of carcasses and products from animals fed estrogen-containing forage. Important pasture and forage plants shown to contain phyto-oestrogens include Trifolium subterraneum L, notably the cultivars Dwalganup, Mt. Barker, Yarloop and Marrar, T. pratense (red clover), T. fragiferum L. (strawberry clover), T. alexandrinum (berseem clover), Medicago sativa (alfalfa or lucerne) and Soya hispida (soya beans). A beneficial anabolic action of the estrogens contained in these plants has been implied, but not unequivically established. More attention has been paid to their noxious effects on livestock. On affected T. subterraneum pasture, castrated male sheep showed lactation, squamous metaplasia of the bulbo-urethral glands and urethral stenosis; infertility, variously attributed to suppression of gonadotrophin release and ovulation; faulty ovum transport; premature regression of corpora lutea; irreversible cystic hyperplasia of endometrial glands on prolonged exposure; dystocia and prolapse of the uterus. Sporadic incidence of phyto-estrogen induced infertility in cattle has been reported, attended by ovarian cyst formation. Estrogenic activity in forage plants has been reported from Australia, New Zealand, India, Sweden, Great Britain, Germany, Denmark, Holland, Finland, Egypt and Israel. The clover constituents chiefly incriminated for these effects are glycosides of the isoflavone derivatives genistein and its 4'-methyl ether biochanin-A, daidzein and its 4'-methyl ether formononetin, and pratensein; coumestrol and its 3'- and 4'-methyl ethers account for the estrogenic activity of alfalfa. The isoflavone content of subterranean clover may reach 3 percent of its dry weight, and the coumestrol content of lucerne may exceed 100 mug/g. Coumestrol and genistein compete with 17beta-estradiol for binding sites on the uterine cytoplasmic receptor and induce macromolecular synthesis in the uterus, but fail to induce ovum implantation in ovariectomized, gestagen-maintained rats. Uterotrophic activity of coumestrol and genistein given parenterally to sheep is approximately 10(-3) and 10(-5) times that of stilboestrol, respectively. Biological activity of ingested phytoestrogens is modified by ruminal micro-organisms and hepatic metabolism...


Recycling and degradation of anabolic agents in animal excreta.

A variety of anabolic agents are currently added to animal feeds to increase growth rate and improve feed efficiency. These compounds and their metabolites are largely excreted. Prior to the use of anabolic agents as feed additives and the advent of confined livestock production, natural recycling occurred which generally resulted in benefit to the animal with no known adverse effects on consumer health. However, the current interest in the use of animal excreta in livestock feed and the possible presence of anabolic agents and their metabolites from this practice has created an additional need for information on the occurrence of anabolic agent residues in consumer products. This report will consider the definition of anabolic agents in its broadest sense and discuss the research on hormones used in animal feed that may be found in animal excreta. In addition to feed additive residues, endogenous compounds may also be found in animal excreta. Endogenous estrogens and androgens have been detected in excreta from domestic livestock and poultry. Research results suggest that substantial estrogenic and androgenic activity may be detected in fresh animal excreta. However, little is known about the effects of various processing methods of excreta such as heat drying and fermentation on its hormonal activity. The effects of feed additive residues and endogenous hormones in excreta used for feed will be discussed relative to their impact on animal health and occurrence in animal products.


Human safety considerations from the use of anabolic agents in foodproducing animals.

The various anabolic agents used in food-producing animals may differ in terms of toxicological considerations related to evaluating human safety. Aside from initial toxicological testing, after chemical characterization of the compound to be administered and its related metabolites expected to occur as residues in food, most synthetic anabolic agents are subjected to chronic/carcinogenicity testing because of usage pattern likely to lead to the occurrence of residues in derived edible products. Initial testing requirements include acute and subchronic studies in appropriate rodent species including a reproduction test with the first generation offspring tested for 90 days post-weaning. This subchronic study serves to indicate potential problems with reproductive performance, foetal toxicity, birth deformities, and other chronic or preneoplastic conditions. The Food and Drug Administration (FDA) may grant approval for certain usages of specific compounds using a 2.000-fold safety margin in relation to a "no deleterious effect" level from the subchronic studies, with upper residue limits of 0.1 ppm in tissue and 0.01 ppm in milk or eggs if there are no indications that further testing should be required. If higher residue limits are requested, the petitioner must perform lifetime testing in two rodent species including in utero exposure and a minimum of three dose levels. Other rodent offspring should be carried for a total of three generations. A six to twelve month study in a non-rodent population is required. Teratology studies might be rquired in at least two species. If no carcinogenic potential is observed, a 100-fold safety margin in relation to the no effect level is generally accepted as the safe exposure level for residues. Should a statistically significant increase in tumors be observed in the test animals as compared to controls, the compound will be classified as a carcinogen or a suspect carcinogen depending on histopathological observations...


[Specific toxicological considerations on anabolic agents; transmitted toxicity].

The growth of populations and the spread of urbanization, resulting in new agricultural structures, have entailed a concentration of livestock production and recourse to new techniques. Of some importance among these techniques is the enteric or parenteral administration of substances in very low doses. These substances include anabolic agents, some of which, like many natural feeds, exhibit hormonal activity. They may be divided into two classes: --those of the DES type, synthetic compounds non-existent in the natural state, --natural agents, which are normally distributed throughout the animal and human organism, and hence in food of animal origin---milk, meat, eggs. The compounds belonging to the second class may also be synthesized and the main toxicological consideration is that they then have to meet clear-cut standards of identity and purity. A compound belonging to the first class, diethylstilbestrol (DES), administered to rats in doses as small as 60 mug/kg of feed or even smaller, causes in general lower growth rates as well as alterations in the genital system and reproductive functions. In long-term experiments (12 months) using rats and mice and applying so-called toxicity "de relais" tests, developed and described by the authors, it also appeared that meat from calves in which DES pellets were implanted under normal rearing conditions, inhibits growth and reproduction in mice and rats fed a diet containing 20% of this meat. Studies in which the livers from treated calves constituted 6% of the diet of these two rodent species also led to the conclusion that fertility was impaired in the second reproduction test. The authors also recall cases of vaginal cancer observed in young girls whose mothers had been treated with DES during pregnancy. Compounds belonging to the second class (estradiol-progesterone and estradiol-testosterone) gave no evidence of harmful effects upon rats when mixed with their rations during short and medium-term trials. Similar results were obtained from studies with rats and mice fed a diet containing 20% veal or 6% liver of calves in which pellets of these natural hormones had been implanted. In these studies, which lasted 23--24 months with rats and 347 days with mice, the toxicity "de relais" test was applied under similar conditions to those undertaken using meat and livers of implanted calves. The report also refers to trenbolone and to "zéralénone" but no toxicity "de relais" tests were carried out with the meat and livers of animals treated with these substances. The authors reached the following conclusions: DES should not be used as an anabolic agent in livestock production. Natural hormones prepared through synthesis or otherwise could be used as anabolic agents in livestock production since no risk to the consumer has been witnessed when they were administered at doses similar to those used in the author's experiments. However, it is recommended that they should be applied under veterinary supervision...


Experimental observations on evaluation of products from anabolic agents-stimulated farm animals.

In the U.S.S.R. the research activities on the use of anabolic agents have been carried out only on an experimental basis by agricultural and human medicine research centres. The evaluation of the animal products from the biological point of view consisted of: 1. evaluation of the biological effect on the laboratory animals; 2. assessment of the breakdown and role of the anabolic agents in muscle tissue and the estimation of the residue amounts of the anabolic agents in meat after slaughter; 3. evaluation of the biological quality of meat obtained from treated animals. Taking into account the above-mentioned directions of the research activities, the influence of diethylstilbestrol was taken into consideration. It has been concluded that the use of diethylstilbestrol leads to detrimental results from the medical authorities' point of view.


Vermipodia - a new type of cell process.

A new kind of cell process is described in leukemic cells in two cases of histiocytic malignancies. They were evident both with light microscopy and scanning electron microscopy. As they have a tubular, worm like appearance, the name vermipodia has been given to them.


Realized and potential neutralization of mutant genes in man by nutritional selection.

Inborn errors of metabolism are examples of monogenic disease in man that, more often than not, impair adaptation. Appropriate modification of the nutritional environment has been used in several instances to offset the phenotypic effects of the mutant allele, with resultant relaxation of selection. Despite an impressive, if brief, record of its efficacy, nutritional treatment of inborn errors of metabolism remains suboptimal in the absence of relevant and superior food technology and well-established systems for its application to the patient. Some of the more commonly encountered multifactorial diseases are likely to yield in the future to the type of genetic analysis that has been effective for monogenic disease. Delineation of various monogenic subsets in a multifactorial disease profile may permit the application of specific treatment to persons in the universal population at particular risk with the disease. Coronary heart disease is an example of a major disease burden now undergoing such delineation, which may benefit from the assignment of specific nutritional and pharmacological treatment for particular forms of the disease.


Distribution of isoenzymes of the glycogenolytic cascade in different types of muscle fibre.

Distinct isoenzyme patterns of the glycogenolytic enzymes exist in different fibre types. Fast twitch glycolytic and slow twitch oxidative fibres differ in the proportion of the two isoenzymes of cyclic AMP dependent protein kinase and in the type of phosphorylase kinase that is present. Slow twitch oxidative fibres and cardiac fibres resemble one another in these two respects, but differ in that the type I phosphorylase of cardiac muscle is absent in slow twitch oxidative fibres. In all examples, the functional differences between the isoenzymes seem to be related to the regulatory rather than the catalytic behavior of the molecules. In the case of cyclic AMP dependent protein kinase and phosphorylase kinase, it is a regulatory subunit that appears to be affected [16,23], while in the case of phosphorylase, the type I isoenzyme is known to have a five to eight-fold Ka for the allosteric activator 5' AMP [6]. However, the precise physiological significance of these differences remains to be elucidated.


Hyperhistaminemia and hyperchlorhydria in basophilic granulocytic leukemia.

A patient with basophilic granulocytic leukemia had hyperhistaminemia, hyperchlorhydria and gastroduodenal ulceration. Because the patient's whole blood, plasma, and urinary histamine levels were increased and the serum gastrin was normal, it was concluded that endogenous hyperhistaminemia was responsible for an ulcerogenic diathesis clinically indistinguishable from that seen in the Zollinger-Ellison syndrome.


Heterogenous glycogen storage disease in one family.

Three brothers, aged 17, 14 and 4 ye presented. Deficiency of glucose-6-phosphatase was associated with deficiency of acid maltase in one and debranching enzyme in the other. Enzyme analyses could not be performed in the youngest sibling.


Leukocyte migration inhibition by cancer patients' sera.

Sera from 38 of 89 melanoma patients, 4 of 15 patients with other cancers and 3 of 43 control donors inhibited the migration of autologous leukocytes. Sera from patients with clinically detectable metastatic disease and from the recipients of BCG were most frequently inhibitory. Autologous sera from 31 of 71 melanoma patients and 3 of 31 control donors increased the leukocyte migration inhibition induced by formalinized melanoma cells. This activity occurred in sera from patients at all stages of malignancy, whether bearing detectable tumour or not and whether receiving BCG or not. Abrogation of tumour-cell-induced leukocyte migration inhibition by serum was less frequent, occurring with 8 of 71 melanoma patients (6 Stage III, 1 Stage I and 1 Stage II) and no control sera. Preincubation of formalinized tumour cells had no effect on their activity in the leukocyte migration assay but the preincubation of melanoma leukocytes with either autologous serum or foetal calf serum inhibited leukocyte reactivity in around 50% of tests. However, this was also seen with control leukocytes and the effect appears to be immunologically non-specific.


Search for anti-tumor response in a bone tumor patient with a long clinical history.

Immunological studies are presented on a patient with a long clinical history suggesting the existence of a tumor-specific immune response. His tumor, first considered benign, progressed to a highly malignant osteosarcoma. Cell-mediated immune reactivity against biopsy cells and against tumor extract was detected in vitro by the autologous tumor stimulation test (ATS) and in vivo by the skin test. In one ATS-test with tumor extract, blastogenesis of T-cells was demonstrated. The amount of Ig(s) in consecutive biopsies increased. Biopsies taken in the later period of the disease stimulated only after trypsin treatment. This stimulation was inhibited by autologous serum or acid eluate of the biopsy. The inhibitory factor in the serum was not intact immunoglobin. Blood lymphocytes did not show a discriminatory or disease-related cytotoxicity, either directly or after co-cultivation with the tumor material. Lymphocytes isolated from one biopsy were non-reactive in both the ATS and the cytotoxicity test.


Serum lipids, uric acid and glucose during chronic consumption of fructose and xylitol in healthy human subjects.

Rapid intravenous administration of fructose and xylitol to human subjects and experimental animals induces profound alterations in the intermediary metabolism. Similar, although less drastic changes are seen after peroral ingestion of large amounts of these sugars. On the other hand, metabolic studies carried out in connection of a 2-year clinical trial of the effects of xylitol and fructose on the development of dental caries (Turku Sugar Study) suggest that the chronic consumption of moderate amounts of these sugars is not accompanied by significant changes in blood chemistry. The lack of metabolic alterations in the long-term experiments is probably explained by slow absorption of fructose and xylitol from the intestine and/or the adaptation of the metabolic system during the chronic use of these sugars.


[Uric acid and phosphate metabolism of the splanchnic region during equimolar parenteral infusion of fructose and glucose].

When fructose and glucose (10 g/5 min., 0.5 g/kg x h) were infused into a peripheral vein, fructose exhibited a transient increase of splanchnic uric acid production. Since phosphate and oxygen uptake rose simultaneously, the effect was considered to be due to well-known cellular drop of nucleotide and phosphate concentrations.


Oxalate excretion during carbohydrate infusions.

Oxalate metabolism was assessed in normal rats and rats deficient in vitamins B-1 and B-6 during intravenous infusions of solutions containing glucose, fructose, sorbitol or xylitol. Urinary excretions of oxalate, glyoxylate and glycine were considerably increased in vitamin B-6 deficient rats infused with xylitol. Significant amounts of 14C-oxalate were excreted only in vitamin B-6 deficient rats infused with U 14C-xylitol. Correction of vitamin B-6 deficiency resulted in a return to normal of urinary oxalate excretion and percentage of U 14C-xylitol excreted as 14C-oxalate. The results suggest that xylitol metabolism produces an increased activity in pathways leading to oxalate formation in vitamin B-6 deficient rats.


[Utilization of glucose and fructose in human liver and muscle].

Hepatic metabolic balances derived from arterio-hepatic-venous substrate differences and hepatic blood flow exhibited similar results during fructose infusion (10 g/5 min., 0.5 g/kg x h) as compared to those from the isolated perfused organ: a portion of 55% of splanchnic fructose uptake was accountable for splanchnic glucose production, 25% for splanchnic lactate and pyruvate production and 20% for glycogen - of fat - synthesis and endoxidation. In account of this hepatic metabolism of fructose, glucose homeostasis and insulin secretion almost maintained. However, the small insulin response did not reduce hepatic free fatty acid utilization to such an extent as to increase pyruvate oxidation. Accordingly, splanchnic production of lactate and pyruvate, descending from fructose was enhanced. Since hepatic-venous lactate: pyruvate substrate ratios did not change, the rise of the arterial redox couple could not be due to hepatic fructose metabolism. According to the findings from the isolated perfused organ, fructose seemed to be phosphorylated at a rate which was found to be 2 to 3-fold that of glucose as calculated from splanchnic utilization rates. This high rate of fructose uptake was reduced with increasing insulin levels. The rapid ATP breakdown was followed by an increment of splanchnic oxygen consumption. The larger energy demand seemed to be satisfied by an enhanced endoxidation of free fatty acids. Since diabetics failed to increase their insulin production, their hepatic fructose phosphorylation rate and consequently their hepatic oxygen demand were not limited. Preliminary results concerning metabolic balances from the human forearm during a steady state of fructose supply, underline the notion that fructose has some effects on intermediary metabolism of skeletal muscle. Accordingly, in juvenile diabetics an enhancement of glucose-, lactate- and pyruvate-uptake could be demonstrated.


Comparative biochemical investigations on the degradation of sugars and sugar alcohols by microorganisms of the oral cavity.

A comparative study on the extent of degradation of glucose, sucrose, sorbitol and xylitol by microorganisms of human saliva and plaques was made by means of the Warburg-technique. Glucose and sucrose are degraded very rapidly producing significant portions of intermediate acid products. Compared to this, sorbitol is degraded slowly at first but then continuously. On the other hand, xylitol is degraded, if at all, in traces only.


Xylitol in relation to the incidence of dental caries.

Two clinical trials were carried out in order to evaluate differences in caries increment as influenced by various sugars. The first study involved almost complete substitution of sucrose (S) by fructose (F) or xylitol (X) during a period of 2 years. The second study comprised partial substitution, the effects of a S- or X-containing chewing gum being compared during 1 year. In the first trial there were no significant differences initially between the sugar groups; 35 subjects in the S-group, 38 in the F-group, and 52 in the X-group. During the entire study 10 subjects discontinued, in one case due to osmotic diarrhoea in the X-group, the other cases being due to difficulties in adhering to the strict diet, other personal reasons and in 3 cases due to excessive caries incidence. After 2 years the mean increment of decayed, missed and filled tooth surfaces was 7.2 in the S-group, 3.8 in the F-group and 0.0 in the X-group. The caries incidence was additionally expressed in combined quantitative and qualitative terms by considering also the changes in lesion size. Irrespective of the way of using these indices, a massive reduction of the caries increment was noted in the X-group as compared to the S-group. The second trial comprised initially 102 subjects divided randomly into S- and X-groups. The subjects consumed 4.5 chewing gums per day in the X-group and 4.0 in the S-group. The frequency of the sucrose intake was 4.94 per day in the X-group, and 4.24 in the S-group. The caries incidence equalled the one-year observations in the first study. The results show a massive reduction of the caries increment not only in relation to total, but also in connection with partial substitution of sucrose and low xylitol consumption. The findings indicate a therapeutic, caries-inhibitory effect of xylitol.


[Comparative study of i.v. administration of xylitol and sorbitol to diabetics].

The aim of this study was to investigate the effects of the intravenous administration of xylitol and sorbitol respectively on plasma insulin and blood glucose in subjects with non-insulin requiring maturity-onset diabetes after an overnight fast. All participants had two intravenous applications with an interval of at least 3 days. Part of the patients started with xylitol and had later on sorbitol; the other part had the reversed sequence. There are two series: Series A: Rapid i.v. application of 0.5 g/kg within 10 minutes (n = 8. Series B: i.v. infusion with 0.5 g/kg/hour for 2 hours (n =9). In addition, 4 subjects of this series had another xylitol infusion after pretreatment with tolbutamide (1000 mg orally 60 minutes before starting the infusion). In respect to insulin secretion there were differences between the two compounds related to the speed of application. With the rapid intravenous injection there was a higher peak and a larger total insulin secretion with sorbitol whereas with the infusion insulin secretion was more pronounced with xylitol. Intravenous application of both carbohydrates caused a certain increase in blood glucose. By pretreatment with tolbutamide the increase of blood glucose due to xylitol could be avoided in spite of the fact that the insulin secretion remained unchanged.


The use of environmental variables in the interpretation of genotype-environment interaction.

The method proposed by Hardwick and Wood (1972) for relating genotype-environment interactions to measures of environmental variables is extended and two examples are discussed.


The effect of cultural transmission on continuous variation.

Cultural transmission may depend on the non-genetic transfer of information from parent to offspring. The consequences of such cultural transmission for continuous variation are investigated theoretically for randomly mating populations. Cultural inheritance may act on genetical and environmental differences between individuals. The consequences for cultural inheritance of polygenic variation and variation due to chance environmental factors are considered. An equilibrium may occur in which the population variance and the covariances between relatives can be expressed as functions of estimable parameters of genetical and environmental variation. Whatever the ultimate origin of culturally inherited differences they are expected to lead to environmental differences between families ("E2" variation). In addition, if cultural transmission maintains differences due ultimately to segregation at many gene loci we may find genotype-environmental covariation is generated.


Estimating the number of genes in a polygenic system by genotype assay.

A new method, genotype assay, is described for estimating k the number of genes or more strictly the number of effective factors responsible for variation of a continuous kind. The central feature is the determination of the proportion of individuals in the Fn generation of a cross between two pure breeding lines that are heterozygous at, at least, one locus by an assay of their Fn+2 grand progeny families. The observed proportion is then equated to a theoretical expectation which is a function of the number of genes involved. Expectations generalised to cover any generation n for experimental designs in which every Fn individual is assayed by comparing two Fn+2 grand progeny families have been derived for two limiting cases; one in which all genotypic differences are expressed as phenotypic differences and the other where the expression is minimised by imposing the maximum and relational balancing out of the contributions of individual gene loci. Equating the observed proportion of heterozygotes to these expectations therefore, leads to an upper and a lower estimate of k corresponding with these two limiting conditions. The reliability and sensitivity of the estimates depends primarily on n the generation chosen for study, the number of individuals (m) assayed from that generation and the number of individuals (l) raised in each Fn+2 grand progeny family. The two variables m and l being the principal determinants of the variances of the family means set the lower limit to the size of the gene effects that can be detected. The method is illustrated by assays of the F3 and F5 generations of two crosses between conditioned lines of Nicotiana rustica for three characters. The estimates are, without exception, as great as or greater than those obtained by alternative procedures. They show large, consistent increases between the F3 and F5 that cannot be traced to greater sensitivity of the latter generation and hence are presumably genuine.


The significance for breeding of linear regression analysis of genotype-environment interactions.

Methods of regression analysis of genotype-environment interaction are considered in relation to existing theory dealing with the relative efficiencies of selection for general or specific adaptation to the environment, and the choice of environments for assessment. The two alternative models is involving regression on to environmental effects (model 2) or genotypic effects (model 3) are equivalent when regression lines are concurrent, but are shown to be mutually exclusive when concurrence is absent...


Acute myelomonocytic leukemia manifested as myelophthisic anemia in a dog.

A 10-year-old, Golden Retriever-type castrated male dog was found to have a hemogram consistent with myelophthisic anemia. Within 30 days the hemogram changed in such a manner that a myeloproliferative disorder was evident. On the basis of hematologic, cytochemical, and cytologic findings, acute myelomonocytic leukemia was diagnosed.


Servo respirator constructed from a positive-pressure ventilator.

We have constructed an electronically controlled respirator from three commercially available components: a positive-pressure ventilator, a recorder pen motor, and a differential amplifier. Using negative feedback derived from a tracheal pressure signal, the instrument functions as a servo respirator which provides precise control of tracheal pressure. The system's power and response characteristics are well suited for ventilation of anesthetized cats and dogs. The servo respirator can be used as an externally controlled respiratory pump which provides flexibility in selection of the parameters of the ventilatory cycle. Alternatively, it can function as a "demand" respirator which generates transthoracic pressure proportional to efferent respiratory discharge.


Tooth pulp projection to the trigeminal complex and jaw opening reflex in the cat.

The J.O.R. elecitied by pulpal, palatal or periodontal stimulations was recorded on the cat digastric nerve. As shown by the frontal sections of the brain stem the caudal subnucleus is not directly involved in this reflex. However after exclusion of the more rostral part of the interpolar subnucleus the pulpal induced J.O.R. is abolished although the palatal or periodontal induced J.O.R. is only partially suppressed.


[Piezo-electric activity of dental tissues].

The appearance of electrical charges on dental samples submitted to 10 daN compression strains was confirmed. In a first series of experiments a correlation was determined between the charges measured and the importance of the organic element at the studied locations. In a second series of measurements carried out on dental specimens after extraction of their organic content there was an almost complete disappearance of the piezoelectric phenomenon. Thus the piezoelectric phenomenon appears essentially in the organic stroma and perhaps also in certain non centro-symmetrical crystals the existence of which has to be demonstrated.


[Structural modifications of secretory epithelial cells of the salivary glands induced by a carbohydrate-rich cariogenic diet in rats].

Rats receiving a carbohydrate rich cariogenic diet (Stephan 580) showed structural modifications of their salivary glands when compared to a control group. These observations suggested that a disturbance of the after birth organogenesis sequences occurred during the experimental period for the submandibular glands. The elaboration of elaboration of secretion granules was strongly decreased in the parotid acinar cells. Such an indirect action of the hyperglucidic diet could contribute to the carious process development by modifying the oral environment.


[Ultrastructural and crystallographic study of human enamel in endemic fluorosis].

The use of physico-chemical and microscopic technics shows that in carie-free fluorotic enamel well-ordered, closely packed, parallelepiped-like crystals can be found as well as hypomineralized areas in which the crystals are disordered and the interprismatic gaps widened. The observation of 1340 crystals shows an increase in their diameter measurements (600 to 700 A instead of 400 to 500 A) and alterations in their morphology, the faces of the crystals remaining nevertheless welldeveloped, in perfect agreement and their hexagonal symmetry. Together with the increase of the fluorosis index, it must be noted that fluoroapatite is progressively filling the place of hydroxyapatite. The coexistence of two different types of apatites within the crystals might be responsible for lattice dislocations involving a greater fragility of the central part of the crystals. The fact that fluoroapatite is very likely localized in the outer part of the crystals could be the reason why they are better resisting demineralization. The central holes within the crystals are not specific of fluorosis, they might rather by due to a demineralization carious process.


[Methods of determination of fluoride in trace amounts. Application to the study of the diffusion of fluoride from an amalgam in dental tissues].

The study of fluoride diffusion in dental tissues has been performed by microprobe analysis. The fluoride supply is carried out in vivo by various fluorides added to conventional amalgams. This method differs then from previous work (topical applications, electrophoresis or fluoride solutions) by the study of fluoride penetration from amalgams either in dentine or in deep enamel, which are more susceptible to caries than superficial enamel. These experiments give evidence of a fast penetration of fluoride into dental tissues, which may be characterized by an apparent diffusion coefficient of about 10(-10) cm2/s.


[Acquisition of masticatory structures in mammalian reptiles (preliminary study].

Possession of the masticatory function and apparatus appears as essential for the passage from Reptiles to Mammals. The present study, based on material of the Museum of d'Histoire Naturelle of Paris and on the literature, tries to distinguish the different stages of modification and specialization of feeding device in the cynodont theriodonts, leading to the mammalian stomatognathic system. The relationship between bone components (lateral skull and lower jaw), teeth and muscles are discussed. Induction of these changes comes from the external adductor muscular system in which the transformation from a primitive mass to mammalianlike masticatory muscles, directs this evolution. The conditions of feeding specialization of the Gomphodonts are discussed, as well as their evolutionary failure. Lastly, without taking up the quarrel about the double jaw-joint, it seems for the authors that the jaw-joint transformation appears as the most determinative element for assigning mammalian origins to the Cynodonts.


Disapperance of osteogenic sarcoma after irradiation: immunologic observations.

Sarcoma - lymphocyte-mediated cytotoxicity and serum blocking of this activity was studied by the in vitro microcytotoxicity test in three patients with osteogenic sarcoma who received preoperative irradiation. All three patients had complete histologic disappearance of the tumor between three to five months after irradiation. Lymphocyte cytotoxicity was present before and after treatment in two patients and post-treatment in one. No serum blocking activity was detected in any of these three patients. They are all alive over four years post-therapy without evidence of active disease.


Granuloma formation in patients receiving BCG immunotherapy.

Eleven patients with acute myeloblastic leukaemia have received repeated intravenous injections of BCG containing 4-9 X 10(6) live organisms per millilitre. Non-caseating epithelioid granulomas, sometimes with giant-cell formation, have been demonstrated in eight bone marrow aspirates. Seven patients had granulomas in the liver, three in the lung, one in the spleen, one in lymph nodes, and one in a skin biopsy. One patient had a raised serum alkaline phosphatase, but none of the patients had any illness which could be related to the presence of granulomas. Granuloma formation appeared more extensive in four patients who were probably anergic before BCG treatment. Until the significance of this finding becomes clear great care should be taken when giving BCG by the intratumour of intravenous routes to potentially immunoincompetent patients.


Gastric pathology and aphagia following lateral hypothalamic lesions in rats: effects of preoperative weight reduction.

The body weights of male albino rats were reduced gradually to 80% of normal body weight by resricting food intake (dieting), and then the rats were given lateral hypothalamic (LH) lesions. Compared with rats of normal body weight sustaining similar brain lesions, the dieted group displayed a shorter period of postoperative aphagia and less gastric pathology. In a second experiment, a group of rats was reduced to 80% of normal body weight by withholding all food (fasting) and then given LH lesions. Compared with dieted rats sustaining similar brain damage, the fasted group displayed a longer period of post operative aphagia and greater gastric pathology. Since the duration of aphagia could be shortened or lengthened by simple manipulations of preoperative body weight, the adequacy of sensorimotor or motivational hypotheses to account for aphagia is questioned. The results are more consistent with the suggestion that gastric abnormalities produced by LH lesions inhibit eating.


An examination model for monitoring clinical competency in operative dentistry.

A model for a clinical competency examination has been presented. Extensive efforts were exerted in standardizing the procedures, the criteria, and the examiners. In addition, the examination was designed to permit isolation and documentation of errors in various phases of a class II amalgam restoration.


Clinical evaluation of a root canal cement that contains paraformaldehyde.

The effectiveness of a Formalin-containing root canal cement in endodontic treatment is evaluated. A total of 76 teeth from 73 patients was used in a series of root canal treatments in which it was impossible to fill the canal to the apex; results of treatment were compared with the results in teeth with conventionally filled canals. The evaluation of the results shows Formalin-containing cements to have a useful place in endodontic therapy.


The use of epsilon-aminocaproic acid for the management of hemophilia in dental and oral surgery patients.

The use of epsilon-aminocaproic acid has proved to be an efficient and practical method for treating hemophiliacs who require dental work. In the past, patients requiring extractions were admitted to a hospital for approximately ten days and received replacement infusions every 12 hours during their stay. This resulted in a large expense because of the cost of the material and the hospitalization itself, not to mention the trauma sustained by the patient both physically and psychologically. Also, by decreasing the number of factor infusions, the risk of complications such as the transmission of hepatitis, allergic reaction, or inhibitor formation decreased. The same protocol using a single infusion of the appropriate factor replacement with supplementary epsilon-aminocaproic acid can be used for the management of patients with other coagulation disorders such as factor IX deficiency (Christman disease), factor XI deficiency, and von Willebrand's disease. Since this paper was submitted, seven more patients have been treated using this protocol. An additional seven odontectomies, 33 extractions, operative dentistry in 18 quadrants, and alveoloplasties in two full arches have been performed. This brings the total to  23 treatment sesions with 18 patients undergoing 124 procedures. One additional minor bleeding episode occurred, resulting in a total rate of four bleeding episodes in 23 treatment sessions and 124 procedures. Our incidence of complications secondary to epsilon-aminocaproic acid specifically remains zero.


The incidence of inflammatory papillary hyperplasia.

The incidence of inflammatory papillary hyperplasia was studied in 892 patients from the dental clinic at the Veterans Administration Hospital in Oklahoma City. The patients were selected if they wore dentures that completely covered the palate. A large number of patients with inflammatory papillary hyperplasia were those who left their dentures in their mouths continuously. Therefore, a high correlation was found between the incidence of inflammatory papillary hyperplasia and the amount of time the patient wore the dentures. Although it is not certain if inflammatory papillary hyperplasia is premalignant, the dentist should try to seek to prevent this abnormal condition by instructing patients to leave dentures out of their mouths for a six-to eight-hour period during each day.


Consumer and provider attitudes toward dentist and expanded auxiliary functions.

Consumers, dentists, dental students, dental assistants, dental hygienists, dental assistant trainees, and dental hygiene students in Massachusetts were surveyed for their attitudes toward the concept of expanded-duties auxiliaries. The Osgood sematic differential technique was used, in which study participants were asked to respond to line drawings of a dentist or an auxiliary performing each of three different procedures: cutting tooth structure, placing a restoration, and taking radiographs. The results indicate that most of the groups perceived significant differences between cavity preparation by the dentist and by the auxiliary: they were modierately positive toward the former, near neutral toward the latter. Groups were more positive toward cavity restoration, generally perceiving fewer, but still significant, differences between the dentist and auxiliary as operatiors. All groups were most positive toward taking radiographs and perceived no difference between the two operators. Of all groups, the dentists perceived the greatest difference between operators; dental hygienists and dental hygiene students were the most positive and saw the least  differences between operators. Consumers were the least positive to all procedures and perveived only modirate differences between the two operators. In other words, the consumers did not seem overly concerned with who provided the dental care; they just did not like the services themselves. In the study, the consumer was more concerned with the procedure than with the different operators, whereas the dentist was more concerned about the operator.


[Studies on the dental gold-alloys. (15). On the age-hardening in AuCu-Pd alloys (author's transl)].

The effects of Palladium addition to stoichiometric AuCu on the age-hardening are studied by means of resistivity, hardness, X-ray diffraction, and optical and electron microscopic observation. The results obtained are summerized as follows. The shapes of the age-hardening curves in the alloys less than 23.4 at. % Pd, showed an abrupt increase at the early stage of ageing. However, in the alloy containing 34.4 at. % Pd, the age-hardening was not observed. The maximum hardness of the AuCu-12 at. % Pd alloy was higher than that of the AuCu-6 at. % Pd and AuCu-23.4 at. % Pd alloys. The difference in hardening in these alloys was explained by the effect of atomic sites of palladium occupied in AuCu superlattice. Optical and electron micrographs showed that twinning occurs in order to relief the elastic strain induced by growth of AuCu I type superlattice platelets.


[On the polymerization of pour type resin (author's transl)].

The initial polymerization point and the polymerization progress have been observed on powder-liquid pour type acrylic resin and one-liquid pour type acrylic resin. The results are as follows: 1. In case of un-heating at the bottom of powder liquid resin, in the former stage the polymerization makes the regular progress from the bottom part to the upper of the mould, but in the latter stage it does some irregular one. In case of heating at the bottom, at first it shows a better regular progress as in the case of un-heating. 2. In case of un-heating at the bottom of one-liquid resin, in the first stage the polymerization makes the regular progress from the bottom part of the resin and at the same time from its middle of the mould, and then to the upper part and the sprue part. In case of heating at the bottom, it begins just from the heated part, then it goes quite regularly to the middle, the upper, and the sprue part, and lastly the polymerization shrinkage concentrates exclusively at the sprue part.


[Comparison between physical properties of resin materials and those of gypsum materials for dental models and dies (author's transl)].

Setting time, water sorption, solubility, dimensional change, hardness, tensile strength, compressive strength, bending strength, and Young's modulus of resin model materials and gypsum model materials were determined. These results are following: 1) Setting time of Goldex is in general the same as that of dental plaster, and setting time of Alpha-Die and that of Dicodur are the same as densite type stone. But setting time of Rock Model is very long, that is, ten times as long as that of densite type stone. 2) Water sorption and solubility of gypsum  model materials are larger than those of resin model materials. Solubility of Dicodur is larger in comparison with the other resin model materials. 3) During setting, all of gypsum model materials expand but all of resin model materials contract. The absolute values of dimensional change of Rock Model and of densite type stones are the same, but smaller compared with those of other materials. 4) The value of knoop hardness of resin model materials is between that of plaster of Paris and that of hydrocal type stones. 5) In comparison with densite type stone, resin model materials are 2.5 to 5.0 times in tensile strength, the same in compressive strength, and 1.5 to 2.3 times in bending strength. 6) Young's modulus of resin model materials is 1/3 to 1/5 as much as that of densite type stones.


[Studies on the cytotoxicity of silver alloys be means of cell culture (author's transl)].

In order to investigate biocompatibility of silver alloys, which is widely used in Japan, L strain cells were brough contact with the alloys. Results were assessed by cell multiplication rate calculated from counting cell nuclei number per milliter of medium and morphological observation. The materials used were two from of silver-tin-zinc alloys, one form of silver-tin-zinc-cadmiumalloy and two forms of silver-copper alloys. Copper-zine alloy, which is reported to be highly cytotoxic, was alsoutilized as a positive control. Following results were obtained: 1) Ingot specimen of these alloys showed cytotoxicity, Silver-tin-zinc alloy, silver-tin-zinc-cadmium alloy and silver-copper alloy containing 10% or less of copper showed intense cytotoxicity initially, with diminishing cytotoxic action with time. On the otherhand, silver-copper alloy containing 20% or more of copper showed persistent cytotoxicity. Copper-zinc alloy showed intense cytotoxicity. 2) Cast specimen of these alloys showed increasing cytotoxicity with time campared to their ingot specimen. The results are seemed to owe much to inclusion of toxic substances from the alloy and investment material or alteration of surface characteristics of the alloys due to casting procedure. 3) Morphological observation did not differ from the results of cell nuclei counting. It is expected that the present results could give a clue on animal experiments or clinical use from the view point of biocompatibility of silver alloys.


[Influence of surface condition upon the cytotoxicity of copper-gold alloy (in vitro) (author's transl)].

Cellular responses to dental alloy may be easily influenced by surface condition of the alloy. From this point of view, the author had a plan to analyse the mechanism of cytotoxic phenomenon of gold-copper alloys, 91% Au-9% Cu, 83% Au-17% Cu, 75% Au-25% Cu, 58% Au-42% Cu, 50% Au-50% Cu, 25% Au-75% Cu, 20% Au-80% Cu, 15% Au-85% Cu, 10% Au-90% Cu, pure gold and pure copper. Test piece of the alloys was heated and treated with solutions of 2% HCl or absolute methanol. The cytotoxicity of the test piece was observed by means of tissue culture, in vitro. There is no cytotoxic action in the cases of pure gold and higher carat alloys than 58% Au-42% Cu alloy, but mild toxicity in lower carat alloys than 50% Au-50% Cu alloy. On the contorary, in the test piece heated and treated with 2% HCl solution, mild cytotoxicity is recognized in the cases of 83% Au-17% Cu and 75% Au-25% Cu alloy. Cellular damage was very severe in the case of lower carat alloys than 50% Au-50% Cu alloy. In the test piece heated and treated with absolute methanol, pure gold, 91% AU-9% Cu and 83% Au-17% Cu alloys have no cytotoxicity, but strong cytotoxicity in the lower carat alloys than 75% Au-25% Cu alloy. Discoloration of the test piece heated and treated with the solution of 2% HCl or methanol, was measured with JIS Colour Chart. Same discoloration was observed in the cases of pure copper, lower carat alloys that 25% Au-75% Cu of the control group, lower carat alloys than 58 Au-42% Cu of 2% HCl treatment group and lower carat alloys than 58% Au-42% Cu of methanol treatment group. From these findings, the discoloration of the alloys caused by heating may be produced by the formation of thin copper-rich-film at the surface of test piece. It is revealed that the cytotoxicity of Au-Cu alloy may be caused by the formation of copper-rich-film at the surface of Au-Cu alloy.


[Notch effect on the fatigue strength of the denture base resin. (Part 3). Effect of reinforcement for composite material with notch (author's transl)].

The denture base which is made from the acrylic resin often occurs the fracture during function, and it is known that this fracture is mainly occured by the fatigue fracture, which is happened by the crack growth from the location of high stress. Until now, the author discussed on the fatigue properties about the specimens with semi-circular notch as the model of the remaining natural teeth, but these results are not easily applied to the design of denture base because the shape of denture base, considering its function and esthetics, is not changed. So, for the improvement of the strength of denture base, the denture base might be used the reinforcement. And, used as a trial the organic fiber as reinforcement, and their effects were investigated from the sides of the bending moment at fracture and the strain distribution occurs the fracture at the posterios palatal area, and its strength is improved 190%. And the fracture of the complete denture happens in general at the location between two central incisors, therefore this problem should be considered as the notched effect. So, reinforcing the lingual part of maxillary anterior teeth using the organic fiber, its strength is improved 53% comparing with the general complete denture. Therefore, the effects of reinforcement were enough appeared, and the improvement of the strength of denture base is very expected in dental use.


[The adhesion of culture cells to some polymers (in vitro)].

Mouse L fibroblasts were grown on such plastic coated coverslips as polyvinyl acetate, cellulose, polymethylmethacrylate, polystyrene and polyvinyl alcohol in in vitro condition, in order to investigate cell contact to various polymeric substrata. Rates of cell multiplication in the presence of the plastics were obtained at the beginning of the experiments, the 2nd day, the 4th day and the 7th day of incubation. Morphological observation in the presence of the plastics were made for 14 hours. Rates of cell multiplication showed no change between most of the experimental groups, i.e., polyvinyl acetate, cellulose, polymethylmethacrylate and polystyrene and control, except polyvinyl alcohol. The cells were deterred from growing with polyvinyl acetate and completely deteriorated on the 4th day of incubation and thereafter. Morphological examination of the adhesion of culture cells to the polymers was made with an arbitrary classification of cell shapes such as round, bipole, spindle or star, depending upon the forms which the cells showed on the substrata under a light microscope, State of adhesion of the cells is considered to be increased in the ascending order of the four classification, polyvinyl acetate was the best in terms of cell adhesion, followed by cellulose, polymethylmethacrylate and polystyrene. The cells did not develop into the advanced state of adhesion in the presence of polyvinyl alcohol. As plastics have become one of the most important biomaterials in recent years, research on biocompatibility of the material, which can be represented by ascertaining of non toxicity, non irritability or non carcinogenecity and adhesion characteristics, is needed. Information on the above would surely be useful in better use of the material and also in developing new materials.


Problems in cranio-facial surgery.

Four geographically widely separated medical centres with a primary interest in cranio-facial surgery present their combined complications to illustrate the dangers and unsolved problems of this surgery. There wre 149 cases with 2 deaths and 3 other life threatening situations (infections). Approximately 60% of the patients had no complications (90/149). Secondary corrections are often necessary to obtain the desired result or correct problems produced by the surgery. The complexity and rarity of the surgery and supporting disciplines is such that in the interest of the patient and the speciality concentration of this surgery in a few centres is desirable.


The lip profile after correction of retromaxillism in cleft and non-cleft patients.

Based on 25 cases with unilateral cleft of lip, alveolus and palate with retromaxillism (CLAP) and 25 cases with pure retromaxillism (RM), the effect on the lip of advancing the maxilla by Le Fort I osteotomy is analysed. It can be shown that on average the base of the upper lip follows the base of the maxilla in a ratio of 4:7. The free end of the upper lip is pushed forwards by the upper front teeth in a ratio of 5:9. This means that to achieve a specified lip advancement, the maxilla has to be brought forward about double the amount. No important between CLAP and RM could be seen. Leaving the nasal spine intact has a favourable influence on movements of the upper lip. The amount of maxillary advancement has no bearing on the ratios. It seems though that thin lips follow the movement of the maxilla better than voluminous lips. There is no satisfactory explanation why the extremes in all groups for all measurements are placed so very far apart. This leads to the conclusion that in spite of careful planning the result in the individual case can differ considerably from that expected.


Nasal abnormalities in facial clefts.

After a short review of their development rare clefts of the nose occurring together with facial clefts are described in a number of clinical cases. These may be divided into 6 groups: 1. clefts of the nose; 2. oblique facial clefts; 3. nasal abnormalities in cleft lip and palate cases; 4. nasal abnormalities in median cleft palate cases; 5. aplasia of the premaxilla; 6. syndromes associated with nasal abnormalities and facial clefts. The discussion deals with the literature, aetiology, prognosis and therapeutic aspects. The publication of individual rare cases is suggested.


Experiences with the use of lyophilized bank cartilage for facial contour correction.

In the Maxillo-Facial Surgical Clinic in Zurich lyophilized bank cartilage (LBC) is used for facial contour reconstruction and elsewhere. In 122 paitents LBC was transplanted 265 times in different sites. The rate of infection was 2.6% the degree of resorption up to 20%. In 7 cases transplanted LBC was removed for histological examination because of over-correction. Xeroradiography is suggested as a method of control even when the cartilage is not calcified.


Malignant tumours in infancy and childhood in the maxillo-facial region.

A series of more than 3.500 tumour cases treated between 1955 and 1974 included 18 children up to the end of 14 years of age. Heading the list of malignant tumours were 15 sarcomata (83.33%). There was conclusive evidence of a relationship between the grade of microscopic differentiation of the tumour and the age of the affected patient. The majority of tumours appearing up to the age of 3 years were sarcomata of the embryonal connective tissue. Those appearing later showed a higher degree of differentiation. The carcinomata were of the adeno-type and the organ affected, the salivary glands. The therapeutic results were more successful than one would have expected for 8 children (53.33%) who had had radical surgery alone or combined with irradiation and chemotherapy. The subjects concerned have developed no recurrences for 5-16 years. Present day progress in highly specialized surgery seems to justify radical surgery even in the child. Oncology centres ought to be created where diagnosis and treatment can be subsidised because malignancies in infancy and childhood are rare.


Thermographic exploration of the parotid region.

Thermography was applied in the pathology of the parotid area in order to see if it is able to complement the clinical examination. The authors present their experience on 17 cases. They could be classed in 3 groups: lesions with normal thermography or non significant modifications, lesions with hypothermia, lesions with hyperthermia. The results indicate that in some cases the information obtained is very useful although up to now differentiation of hyperthermia of different origins is difficult.


Structures of the midface on cylindrical pantomograms.

The paper presents the anatomical structures of the middle third of the face as they are visualized in cylindrical pantomograms, in the projections found to give maximum information in my earlier experimental study (Altonen 1972). The pantomograms are taken with the prototype equipment developed since the earlier study, which can be used to take orthopantomograms, concentric patomograms of the desired shape, and linear tomograms. With this equipment, the patient can be examined while lying down, and experiments with corpses of road traffic victims have shown that it is particularly useful for diagnosing fractures in the middle third of the face. Maximum information is given by a projection in which the radiation beam traverses the region to be visualized parallel to the Frankfort plane, and in which the diameter of the cylindrical image layer corresponds to the width of the middle third of the face. The central part of the middle region is visualized best in ca. 30 degrees retroversion, with the exception of the alveolar process of the maxilla, the hard palate and the dentition. The best reproduction of the lateral areas of obtained in ca. 25 degrees anteversion. The contusing shadows cast by the cranial base in radiography of the middle facial region can be shifted from the area to be examined by tilting the head forward or backward, or positioning the rotational axis of the beam dorsally to the porion-porion line. Thin shadows can also be shifted by using stereoscopic pantomography.


Aspects of extra-oral pressure osteosynthesis.

The author reviews advantages and disadvantages of some monomandibular fixation methods. He indicates the most important disadvantages of so-called pressure osteosynthesis with the aid of plates and screws. The author obtains the required pressure on the fracture surface by means of an extra-oral screws fixed in a plastic frame, the stability of which is supported by 3 steel pins. The application of this method will be explained and reviewed with some typical examples.


The therapeutic result of excision of the superficial temporal artery in atypical migraine.

A short review of the biochemical and clinical concepts of migraine and the different therapeutic approaches as well as the surgical procedure for the treatment of migraine is followed by the description of the treatment of eight patients suffering from atypical migraine. The selection of patients for this operation is limited to those cases suffering from classic migraine with the migraine attacks occurring in one and always the same side of the face and head. A step by step account of the procedure for the excision of a part of the super-zygomatic part of the superficial temporal artery is given with the results and the four year follow-up. In selected cases of atypical migraine, the above simple operation, may be curative.


The interdental brush and its place in operative and crown and bridge dentistry.

The effect of the interdental brush was evaluated on sixty-seven extracted teeth which were stained and examined under the stereomicroscope. Thirty-one of the teeth were totally covered with plaque when the interdental brush was used on them immediately before extraction. Thirty-six of the teeth were from patients who had used the interdental brush routinely for several years. The interdental brush was found to have an excellent effect both in the central part of the interdental space and on the embrasures. However, the most noteworthy finding was that it removes plaque as far as 2-2 1/2 mm below the gingival margin. This means that restorations can be kept free of plaque, even if they are extended into the pocket. In modern dentistry 'extension for prevention of dental caries' has become a controversial principle because subgingival restorations retain plaque which induces destructive periodontal disease. In many cases this problem can be solved by introducing the interdental brush.


Quantitative changes in dental plaque formation related to removable partial dentures.

Plaque formation on forty-four teeth acting as abutments for removable partial dentures was studied while the patients were wearing their dentures and while they were not. The amount of plaque was assessed according to Quigley & Hein (1962), modified by Kardel & Bay (1967). In addition, that formed occlusally was evaluated by an occlusal plaque scoring index designed for the present study. It was found that the wearing of partial dentures increased the formation of plaque on all tooth surfaces under investigation.


Abrasion of restorative materials by toothaste.

The procedure developed in this investigation is suitable for determining the abrasion resistance of restorative materials to toothbrush/dentifrice abrasion. Ideally, a restoration should have an abrasion resistance similar to that of enamel. Of the materials tested, gold was the only one that wore slightly less than enamel, whilst amalgam wore almost twice as quickly. The silicate material and composites (excluding TD.71) wear away 2-4 times faster than enamel. TD.71 and especially the unfilled resin exhibited very high rates of abrasion. After prolonged toothbrush/dentifrice abrasion, the surfaces of gold and amalgam were considerably smoother than those of the silicate and composite materials.


In vitro attachment of Streptococcus sanguis to dental crown and bridge cements.

The ability of a common dental plaque bacterium, Streptococcus sanguis, to adhere to dental crown and bridge cements in vitro was investigated. Cylindrical blocks of five different commercial brands of cement, with and without acquired pellicles, were indubated with buffer suspensions of S. sanguis for 1 h. Attached bacteria were counted under the microscope. S. sanguis had particularly high affinity for uncoated resin cement. In contrast, the carboxylate cement tested was a poor substrate for the adherence of this bacterium. The other cement types (zinc phosphate, zinc oxide and silico-phosphate) had intermediary qualities as adhering surfaces. The presence of an acquired pellicle, obtained by pretreatment with saliva, influenced the initial adherence of bacteria to cement in vitro. On the resin cement a salivary pellicle strongly suppressed the bacterial adhesion. For the zinc phosphate, zinc oxide and silico-phosphate cements a pellicle slightly enhanced the attachment of S. sanguis. On the carboxylate cement only few organisms attached also after pretreatment with saliva.


Soft lining to relieve soreness beneath dentures.

The mandibular dentures of eighteen patients who suffered from chronic tissue soreness beneath the denture which could not be relieved by bringing the denture into a functionally faultless condition, were furnished with a soft lining. Of the patients re-examined after 2 weeks, 89% were symptom-free. After 6 months, 1, 2 and 3 years the percentages of the symptom-free patients were 64, 79, 60 and 71% of the total re-examined. However, after soft lining, some relief of the complaint was reported by all patients of the series. The series included a woman with bronchial asthma whose oral mucosa again became sore after she had worn the denture with soft lining for a year, and a bruxist who had a definite relief. The percentage incidence of denture stomatitis increased in the course of the 3-year period studied. At the listed dates of re-examination, it was 25, 46, 43, 80 and 100%, respectively.


Physical properties of a nickel-base alloy prepared by isostatic pressing and sintering of the powdered metal.

The physical and mechanical properties of samples of a nickel-base alloy fabricated by powder metallurgy were determined. The particle sizes of the powders used to make the samples varied from -80/ +200 mesh to -325 mesh. The compaction pressure varied from 138 to 414 MN/m2 and the sintering temperature varied from 1150 to 1250 degrees C. The shrinkage during processing, the porosity, tensile strength, yield strength, elongation, and elastic modulus were used to characterize the samples. The strength of the samples generally increased with decreasing particle size of the powder and increasing compaction pressure and sintering temperatures. The porosity and strength, therefore, could be varied over a wide range by controlling the various parameters. The properties of the samples prepared by powder metallurgy were compared with those of the cast alloy and compact bone. Conditions can be selected that will yield equivalent or better properties by powder metallurgy than by casting.