Expression of human and suppression of mouse nucleolus organizer activity in mouse-human somatic cell hybrids. Most mouse-human somatic cell hybrids show preferential loss of human chromosomes, absence of human 28S ribosomal RNA, and suppression of human nucleolus organizer activity, as visualized by the Ag-AS silver histochemical stain. In contrast, the mouse-human hybrids studied here show preferential loss of mouse chromosomes. The hybrids were made by fusion of HT-1080-6TG human fibrosarcoma cells with BALB/c mouse peritoneal macrophages or strain 129 mouse teratocarcinoma cells. The Ag-AS staining method shows nucleolus organizer activity of chromosomes 13, 14, 15, 21 (rarely), and 22 in the human parent and chromosomes 12, 15, 16 (rarely), and 18 in  the BALB/c mouse parent. In the hybrid cells the human nucleolus organizer regions are active, as shown by Ag-AS staining and involvement in "satellite association." The mouse nucleolus organizer regions are not stained by the Ag-AS method even though mouse chromosomes 12, 15, and 18 are present in the BALB/c hybrids and at least one copy of each mouse chromosome is present in the teratocarcinoma-derived hybrids. Thus, in these mouse-human hybrids, unlike those that lose human chromosomes, only human nucleolus organizer activity is expressed, and mouse nucleolus organizer activity is suppressed.


Hormone responsive human breast cancer in long-term tissue culture: effect of insulin. The mechanisms of steroid and peptide hormone action in human breast cancer are poorly understood. We have previously characterized a cell line of human breast cancer in long-term tissue culture that possesses various steroid hormone receptors and responses, providing a model for the study of steroid hormone action. The present studies describe a human breast cancer in vitro that responds to physiologie concentrations of insulin with an increased rate of macromolecular synthesis and growth. Thymidine and uridine incorporation in cells in serum-free medium are stimulated by 10(-11) M insulin and are maximal with 10(-8) M. Leucine incorporation is stimulated by 5 X 10(-11) M insulin and is maximal with 10(-9) M. Significant stimulation of uridine and leucine incorporation is evident by 3 hr and maximal by 10 hr. A 10-hr lag period exists for insulin stimulation of thymidine incorporation, which is maximal form 14 to 24 hr. The effect of 10(-8) M insulin on macromolecular synthesis is accompanied by a 69% increase above controls in the number of cells after 24 hr. The effect on macromolecular synthesis is observed in glucose-free medium. Insulin's effect on protein synthesis is not blocked by inhibition of RNA synthesis with actinomycin D. Glucocorticoids partially inhibit the action of insulin in these cells. This system provides a model for studying insulin action, and suggests that some human breast cancer may show growth regulation by insulin.


Cellulose biosynthesis in Acetobacter xylinum: visualization of the site of synthesis and direct measurement of the in vivo process. In vivo synthesis of cellulose by Acetobacter xylinum was monitored by darkfield light microscopy. Cellulose is synthesized in the form of a ribbon projecting from the pole of the bacterial rod. The ribbon elongates at a rate of 2 mum min-1. The ribbon consists of approximately 46 microfibrils which average 1.6 X 5.8 nm in cross section. The observed microfibrillar elongation rate corresponds to 470 amol of glucose/cell per hr assimilated into cellulose. Electron microscopy of the process using negative staining, sectioning, and freeze-etching indicated the presence of approximately 50 individual synthetic sites organized in a row along the longitudinal axis of the bacterial rod and in close association with the outer envelope. The process of cellulose synthesis in Acetobacter is compared with that in eukaryotic plant cells.


Structure and transformation of chitin synthetase particles (chitosomes) during microfibril synthesis in vitro. The fine structure of isolated chitin synthetase (UDP-2-acetamido-2-deoxy-D-glucose:chitin 4-beta-acetamido-deoxyglucosyltransferase; EC 2-4-1-16) particles (chitosomes) from Mucor rouxii and the elaboration of chitin microfibrils were studied by electron microscopy. Chitosomes are spheroidal, but often polymorphic, structures, mostly 40-70 nm in diameter. Their appearance after negative staining varies. Some reveal internal granular structure enclosed by a shell measuring 6-12 nm thick; others do not show internal structure but have a pronounced depression of the external surface. In thin sections, isolated chitosomes appear as microvesicular structures with a tripartite shell 6.5-7.0 nm thick. Morphologically similar structures can be seen in intact cells of M. rouxii. Isolated chitosomes undergo a seemingly irreversible series of transformations when substrate and activators are added. The internal structure changes, and a coiled microfibril (fibroid) appears inside the chitosome. The shell of the chitosome is opened or shed, and an extended microfibril arises from the fibroid particle. During prolonged incubation, the fibroid coils become less common and extended microfibrils appear thicker. We regard the chitosome as the cytoplasmic container and conveyor of chitin synthetase en route to its destination at the cell surface. Isolated chitosomes are well suited for integrated ultrastructural-biochemical studies of microfibril biogenesis in vitro.


Concanavalin-A-induced transmembrane linkage of concanavalin A surface receptors to intracellular myosin-containing filaments. With normal rat kidney cells in monolayer culture, we have studied the distribution on the cell surface of receptors for concanavalin A, and the distribution of the smooth muscle myosin-like protein inside the same cell, using specific fluorescence microscopic methods. The concanavalin A receptors were initially uniformly dispersed over the cell surface, but 20 min after the addition of concanavalin A at 37 degrees, the receptors showed a variety of nonuniform surface distributions, including extended parallel linear arrays. These arrays of receptors were found to be superimposed on the linear arrays of the intracellular myosin-containing filaments, indicating that a transmembrane linkage of the receptors and the filaments had occurred. This linkage required a lateral redistribution of concanavalin A receptors, since it did not occur with succinylated concanavalin A, but was subsequently induced if the cells that had been reacted with succinylated concanavalin A were then treated with antibodies to concanavalin A. The redistributions of concanavalin A receptors on the surfaces of these normal rat kidney cells, however, were much less extensive than the patching that was induced on the surfaces of the same cells infected with, and transformed by, Rous sarcoma virus.


Possible role of nucleus-membrane interaction in capping of surface membrane receptors. Interaction of multivalent ligands and cell surface receptors can induce redistribution of these receptors to form patches and caps. In this study, we have investigated the role of nucleus-membrane interaction in the capping of membrane components. Mouse L cells and leukemia EL4 cells were enucleated with the aid of cytochalasin B, yielding cytoplasts and karyoplasts. Capping of surface receptors was induced by allo- and hetero-immune sera followed by fluorescein-conjugated antiglobulin serum, or by the plant lectin concanavalin A. Capping could easily be induced in intact cells, but virtually no capping was detected in the nucleus-free cytoplasts. Interestingly, karyoplasts, which posses cell-membrane components but very little cytoplasm, could be easily induced to cap their surface antigens. Hence, cap formation of membrane components seems not to be an autonomous membrane process. The data suggest that interaction of surface membranes and inner cell components associated with the nucleus is involved in the movement of surface membrane receptors.


Studies of human myasthenia gravis: electrophysiological and ultrastructural evidence compatible with antibody attachment to acetylcholine receptor complex. Neuromuscular junctions from patients with early onset and chronic myasthenia gravis were examined by electrophysiological and ultrastructural techniques. Acetylcholine (AcCh) sensitivities were reduced by 34-63% in early onset myasthenia and 60-80% in chronic myasthenia. Ultrastructural analysis revealed that virtually all junctional folds of the early onset patients were intact but that the AcCh-receptor-rich crests of these folds were uniformly covered by an attached layer of 30 X 70 A particles arranged in small tufts or rosettes. In chronic myasthenic endplates, however, junctional fold crests were destroyed, apparently being replaced by vesicular membrane debris similarly labeled by tufts of 30 X 70 A particles. Thus, the initial reduction in junctional AcCh sensitivity observed in early onset myasthenia gravis may be attributed at least in part to in situ masking or inactivation of AcCh receptors, whereas the marked decrease in AcCh sensitivity observed in the chronic myasthenic patient may represent a combination of two factors: (a) in situ masking of AcCh receptors and (b) destruction of the receptor-containing crests of the junctional folds. These observations are compatible with an autoimmune etiology of myasthenia gravis initially involving an apparent antibody attachment to one or more components of the functional AcCh receptor complex, followed by systematic destruction and removal of junctional folds by both humoral and cell-mediated autoimmune responses.


Lateral motion of fluorescently labeled acetylcholine receptors in membranes of developing muscle fibers. We have made direct, quantitative measurements of the lateral motion and age-dependent distribution of acetylcholine receptors (AChR) on the surface of rat myotubes in primary culture. AChR were fluorescently marked with tetramethylrhodamine-labeled alpha-bungarotoxin and AChR lateral motion was measured by the fluoresence photobleaching recovery technique. We found two coexisting distinct classes of AChR: (i) mobile, uniformly distributed AChR that appear on all myotubes shortly after fusion from myoblasts; and (ii) immobile, dense, highly granular AChR in patches of 10-60 mum size that appear shortly after fusion and disappear after myotubes have become extensively interconnected. In addition, evidence of turnover of AChR labeled with tetramethylrhodamine-alpha-bungarotoxin is seen in the gradual internalization of surface fluorescence within 36 hr after labeling. The relevance of these results to an understanding of the membrane dynamics and localization of muscle AChR is discussed.


Snythesis of polypeptides with the properties of myosin light chains direct by RNA extracted from muscle cultures. Polyadenylylated RNA, extracted from differentiating primary cultures of rat muscle and the myogenic cell line L8, directs the synthesis of polypeptides in the wheat germ cell-free system which comigrate with myosin light chains under several electrophoretic conditions. The peptides also associate specifically with heavy myosin subunits during dissociation-reassociation treatment. Intact cells of primary skeletal muscle cultrues and of the myogenic line synthesize predominantly two ligh chains. RNA extracted from primary muscle cultures directs the synthesis of a third polypeptide in the cell-free system, similar to the third light chain found in myosin extracted from adult rat thigh muscle. Products of cell-free systems directly by RNA extracted from fibroblasts, reticulocytes, and myeloma cells did not contain detectable amounts of similar polypeptides.


Group selections among laboratory populations of Tribolium. Selection at the population level or group selection is defined as genetic change that is brought about or maintained by the differential extinction and/or proliferation of populations. Group selection for both increased and decreased adult population size was carried out among laboratory populations of Tribolium castaneum at 37-day intervals. The effect of individual selection within populations on adult population size was evaluated in an additional control series of populations. The response in the group selection treatments occurred rapidly, within three or four generations, and was large in magnitude, at times differing from the controls by over 200%. This response to selection at the populational level occurred despite strong individual selection which caused a decline in the mean size of the control populations from over 200 adults to near 50 adults in nine 37-day intervals. "Assay" experiments indicated that selective changes in fecundity, developmental time, body weight, and cannibalism rates were responsible in part for the observed treatment differences in adult population size. These findings have implications in terms of speciation in organisms whose range is composed of many partially isolated local populations.


Single burst study of rec- and red-mediated recombination in bacteriophage lambda. Single bursts from three-point crosses of bacteriophage lambda were analyzed for recombination of markers several thousand nucleotide pairs apart. Single recombination, mediated by the rec system of Escherichia coli, is usually reciprocal. Double recombinants are also significantly correlated in single bursts, although the correlation is weaker than for reciprocal singles. Reciprocity is not found in crosses mediated by the lambda red system. With respect to certain other paraments of recombination, the two systems appear to be alike. Double recombinants usually result from one event, not from two independent single recombinations, and their average clone size is about half that of single recombinants. The results are discussed in terms of current molecular models of recombination.


Assignment of a locus required for flavoprotein-linked monooxygenase expression to human chromosome 2. Hybrid clones segregating human chromosomes were prepared by fusing mouse RAG cells to fresh human bone marrow cells and tested for the mixed-function oxygenase [flavoprotein-linked monooxygenase; RH, reduced-flavoprotein:oxygen oxidoreductase (RH-hydroxylating); EC 1.14.14.1] arylhydrocarbon hydrocarbon hydroxylase. Neither constitutive nor induced aryl hydrocarbon hydroxylase activity was detected in parental RAG cells. Induced aryl hydrocarbon hydroxylase was expressed in 4 out of 12 primary and 12 out of 19 secondary hybrid clones examined. Constitutive hydroxylase activity was detectable in 9 of the 15 inducible clones. All of the hybrid clones that exhibited constitutive hydroxylase activity were also inducible. There was a positive correlation between constitutive and induced hydroxylase activities although the absolute levels of the enzyme showed a wide range between different clones. Isozyme analysis performed on 12 primary and 19 secondary hybrid clones showed that aryl hydrocarbon hydroxylase activity was concordant with the expression of the human isozymes malate dehydrogenase (EC 1.1.1.37) and isocitrate dehydrogenase (EC 1.1.1.42), previously assigned to human chromosome 2. Isozyme markers for 19 other human chromosomes segregated independently from aryl hydrocarbon hydroxylase activity. The results suggest that the gene(s) required for aryl hydrocarbon hydroxylase activity are located on human chromosome 2.


Bioenergetics in clinical medicine: prevention by forms of coenzyme Q of the inhibition by adriamycin of coenzyme Q10-enzymes in mitochondria of the myocardium. Adriamycin inhibits the succinoxidase system and the NADH-oxidase system. Both of the intact mitocondrial enzymes and the pentane-extracted preparations are inhibited. The inhibition can be prevented by a molar ratio of coenzyme to adriamycin of 3:1 for coenzyme Q10 (ubiquinone), 5:1 for coenzyme Q7, and 5:1 for coenzyme Q4. Prevention of inhibition was observed in the decreasing order of coenzyme Q10 greater than coenzyme Q7 greater than H6 coenzyme Q4 greater than coenzyme Q4. Adriamycinone was three times more inhibitory than adriamycin, which is compatible with a less polar fragment necessary to inhibit the lipoidal coenzyme Q10. Daunomycinone was not inhibitory at a concentration at which adriamycinone is effective, indicating that the hydroxyl group of the latter could be binding at the receptor, since it should not influence electron transfer or rings B and C.


Do highly oncogenic group A human adenoviruses cause human cancer? Analysis of human tumors for adenovirus 12 transforming DNA sequences. Adenovirus 12 (Ad12) (Huie) (highly oncogenic group A) readily induces tumors in newborn rodents. Since Ad12 is isolated from human fecal samples, we investigated whether it plays a role in the etiology of human gastrointestinal cancer. If Ad12 is a causal agent of human cancer, then human tumors should contain Ad12 transforming genes, as indicated by studies of cells transformed in vitro and in vivo by oncogenic viruses. Ad12 DNA and the Ad12 transforming restriction fragment (EcoRI-C fragment, left 16% of the viral genome) were labeled in vitro to 10(7) to 4 X 10(8) cpm/mug by the nick translation reaction of DNA polymerase of Escherichia coli. The fidelity and sensitivity of these probes were established by (i) analysis of DNA from Ad12-transformed cells and from hamsters with tumors induced by Ad12, (ii) reconstruction experiments with added Ad12 DNA and EcoRI restriction fragments, and (iii) comparison of annealing characteristics with Ad12 probes labeled in vivo. With Ad12 [3H]DNA as probe, no viral DNA sequences were detected in 18 normal gastrointestinal tissues and 34 gastrointestinal tumors, including cancers of the colon, rectum, small intestine, and stomach, under conditions that would detect 0.1 copy of the Ad12 genome per tumor cell. Similar analyses of Ad12-transformed hamster cells and Ad12 primary hamster tumors indicated 6-18 copies per cell of over 90% of the viral genome. With the Ad12 EcoRI-C transforming fragment as probe, no hybridization was detected with 32 human gastrointestinal tumors and five normal tissues; this result excludes 1-2% of the Ad12 genome per tumor cell. Our date are strong evidence that Ad12 is not a major cause of human gastrointestinal cancer. The Ad12 transforming EcoRI-C fragment hybridized (50-68% efficiency) with other Ad12 isolates and with Ad18 and 31 (members of oncogenic group A), but not at all with 28 other human Ad serotypes (manuscript in preparation). Thus other group A members probably are also not involved in human gastrointestinal cancer. No viral DNA sequences were detected in 12 normal lungs and 22 lung tumors, suggesting that respiratory cancer does not involve an Ad12 etiology.


Enzyme replacement therapy in Gaucher's disease: a rapid, high-yield method for purification of glucocerebrosidase. Gaucher's disease is caused by a deficiency of the lysosomal enzyme glucocerebrosidase (glucosylceramidase; D-glucosyl-N-acylsphingosine glucohydrolase, EC 3.2.1.45); this disorder has been a leading candidate for enzyme replacement trials. A rapid, high-yield method for purification of glucocerebrosidase has been developed. Detergent extraction of human placenta was followed by salt fractionation, concanavalin A-Sepharose chromatography, organic solvent precipitation, and affinity chromatography on phosphatidylserine-agarose; the total yield is 60% with 6000-fold purification. Purified glucocerebrosidase has been administered intravenously to a volunteer Gaucher's patient on two separate occasions. For the first injection, the enzyme was entrapped in resealed erythrocytes; for the second injection, the enzyme was given without any carrier. The enzyme infusions caused no untoward effects.


Opiate and stimulus-produced analgesia: functional anatomy of a medullospinal pathway. Neurons in ventromedial medulla, including the nucleus raphe magnus, project to trigeminal nucleus caudalis and, via the dorsolateral funiculus, to spinal dorsal horn. The terminals of this descending system are in loci containing cells responsive to noxious stimuli. Electrical stimulation of nucleus raphe magnus selectively inhibits spinal dorsal horn neurons that respond to noxious stimuli. These neurons are located near the anatomically demonstrated terminals of this descending system. Dorsolateral funiculus lesions block this descending inhibition of spinal neurons as well as the analgesic action of morphine. This evidence supports the hypothesis that this neuron population mediates the analgesia produced by opiates and electrical stimulation of certain diencephalic and brainstem sites.


Force-velocity characteristics for calcium-activated mammalian slow-twitch and fast-twitch skeletal fibers from the guinea pig. Twitch fiber bundles from a slow (soleus) and a fast (extensor digitorum longus) mammalian muscle after mild chemical treatment were activated with calcium and relaxed in calcium-free solution. Like the electrically activated whole muscles, the force-velocity relationship was such that, at each relative load, the steady speed of shortening for the fast fibers was about two times greater than that for the slow twitch fibers. The duration of pre-steady motion in the two types of fibers was the same. The data provide direct evidence that the difference in the shortening characteristics of the two types of fibers is due to differences in their cross-bridge properties.


Direct determination of surface tension in the lung. We have used the spreading behavior of small drops of several fluorocarbon fluids and silicone oil on air-liquid interfaces to measure the surface tension of lungs in situ. The test fluids were calibrated in a surface balance at 37 degrees on monolayers of dipalmitoylphosphatidylcholine. At particular surface tensions characteristic of each fluid used, an increase in the tension of 1 mN/m or less caused the droplets to spread reversibly from a sphere to a lens shape. Using micropipettes we placed such droplets on the alveolar surfaces of excised rat lungs held at functional residual capacity and 37 degrees and found that the surface tension remained below 9 mN/m for at least 30 min. The surface tension-volume relationship was linear for tensions ranging from 9 to 20 mN/m.


Effects of deuterium oxide on mechano-sensory receptor. In the crayfish stretch receptor organ, a total substitution of D2O for H2O in the bathing solution produced a decrease in the amplitude of the receptor potential to a level of 34% of the control. The electrical resistance of the receptor neuron was slightly increased by the D2O substitution. The input capacitance of the neuron was unchanged. The viscoelastic properties of the receptor muscle were not altered by D2O. Thus, we conclude that D2O has an inhibitory effect on the transduction process which links the deformation of the dendrites with the permeability increase that is responsible for the receptor potential.


Diabetogenic peptide from human growth hormone: partial purification from peptic digest and long-term action in ob/ob mice. Studies in female ob/ob mice demonstrated diabetogenic properties of human growth hormone (somatotropin) and of a fragment generated therefrom by controlled digestion with pepsin; both the fragment and parent growth hormone produce long-term effects on carbohydrate metabolism; in acute glucose tolerance tests, only the fragment is active. Two nonacidic diabetogenic fractions have been separated from inactive fractions by chromatography on Bio-Gel P-6 followed by ion exchange chromatography at pH 4.3 and gel filtration on Bio-Gel P-2 and/or Sephadex G25; these active fractions exhibited multiple NH2-terminal (Lys, Phe, Leu, and Tyr). Fraction CD has these characteristics: (i) It induces glucose intolerance in fasting female ob/ob mice when injected subcutaneously in a divided dose, 15 min before and concurrently with glucose; mice injected with sufficient peptide exhibit elevated fasting glucose levels as long as 7 months after a single glucose tolerance test. (ii) It is a peptide smaller than that reported to stimulate body growth, but larger than somatostatin. This peptide, as reported earlier, does not crossreact with antiserum to human growth hormone in radioimmunoassay.


Urinary dimethyltryptamine and psychiatric symptomatology and classification. The excretion of dimethyltryptamine (DMT) was studied amongst 122 recently admitted psychiatric patients and 20 normal subjects. DMT was detected in the urine of 47% of those diagnosed by their psychiatrists as schizophrenic, 38% of those with other non-affective psychoses, 13% of those with affective psychoses, 19% of those with neurotic and personality disorders and 5% of normal subjects. Ninety-nine patients were interviewed in a semi-standardized fashion, and also categorized according to a variety of operational definitions of the psychoses. The operational definitions failed to reveal any group significantly more correlated with urinary DMT than a hospital diagnosis of schizophrenia, but a discriminant function analysis of symptomatology could be used to define a group of 21 patients of whom 15 (71%) excreted detectable DMT. There was a general relationship between psychotic symptoms and urinary DMT, but specifically schizophrenic symptoms did not appear to be major determinants of DMT excretion.


Quantitative cytochemistry of glycogen in blood cells. Methods and clinical application. Quantitative glycogen determinations can be made in single blood and bone marrow cells, using microspectrophotometry or microfluorometry after staining with variants of the periodic acid--Schiff (PAS) reaction. These PAS variant reactions generally do not indicate the presence of non-glycogen PAS-positive substances, known to be prevalent in various hematopoietic cells, possibly due to masking of reactive groups. The specificity of the reaction in blood cells was ascertained by alpha-amylase digestion, which removed more than 95% of the PAS-positive material. Calibration of the PAS reaction was undertaken with a microdroplet model of pure leukocyte glycogen. The glycogen amounts in the droplets were determined by microinterferometry, the droplets were stained with a variant PAS reaction, and the total extinction of the reaction product in the stained droplets was determined by microspectrophotometry. The extinction coefficient (k) was obtained from the equation k equals Etot divided by M where (Etot) is the total extinction as determined by microspectrophotometry and (M) the dry glycogen amount as determined by microinterferometry. The microinterferometric dry mass determinations were calibrated by X-ray absorption in order to obtain the absolute amounts of glycogen. For practical purposes a reference system was made of normal neutrophil leukocytes. The glycogen content in the reference neutrophils was first determined with the micromodel. These neutrophils, now with a known glycogen amount, were stained with the PAS reagents and measured microspectrophotometrically in parallel with cells containing an unknown glycogen amount. Alternatively, the staining was made with a fluorescent PAS reaction, and the glycogen content determined by microfluorometry. Both methods appeared suitable for determining the glycogen content of blood cells from patients with various diseases, though the microfluorometric method was preferable for measurements of small amounts of inhomogeneously distributed glycogen. The mean glycogen content of normal neutrophil leukocytes was found to be 13.6 times 10(-12) g. The content was increased in infectious diseases such as pneumonia and tonisillitis, as well as in polycythemia vera and myelofibrosis, while low amounts were found in untreated chronic myelocytic leukemia. In chronic myelocytic leukemia in remission, the glycogen content of mature neutrophils had completely normalized. Erythroblasts normally do not contain detectable amounts of glycogen. However, in certain diseases such as beta-thalassemia and Di Guglielomo's syndrome, appreciable amounts of glycogen accumulate in the erythropoietic precursor cells. In beta-thalassemia this was associated with an arrest in the proliferation of early polychromatic erythroblasts, which accumulate glycogen in the G1 phase of the cell cycle. In all these diseases quantitative glycogen determinations in the blood cells have diagnostic importance.


[Resistance to traction forces in different brands of amalgam]. In a previous study the initial tensile strength of several dental amalgams after 15 minutes has been investigated. The present study scrutinized a large number of dental amalgams for the tensile strength after 15 minutes up to 60 minutes. All the dental amalgam specimens used in this study were prepared according to A.D.A. specification no. 1. The results obtained from this study show that out of the twenty three dental amalgams only approximately the half conformed to the minimum value of 2.0 MN/m2 as required for the tensile strength after 15 minutes by A.D.A. specification no. 1. Contrary to the results obtained by other investigators, the dental amalgam obtained from the spherical type of alloys does not acquire a superior initial strength in comparison with those from the conventional types of amalgam alloys. In this study the new dental amalgam alloy Indiloy (n.z.) (Shofu Corporation, Japan) demonstrated a superior tensile strength for all the testing times. If the tensile strength after 15 minutes is taken as a selection criterion, the five best alloys in this investigation are Indiloy (n.z.), Optalloy II, Micro II, Revalloy and Cavex SF. If the previous study is considered likewise. Dispersalloy (fast setting form) should be taken into account as well.


Morphological characterisation of adult acute leukaemia in short-term liquid culture. Peripheral blood leukocytes from 31 out of 48 patients with acute myelogenous leukemia grew in short-term liquid culture. Two distinct types of growth occurred. The first type was dimorphic with supernatant free-floating ("non-sticker") cells and, in addition, a plastic/glass adherent, trypsin resistant, phagocytic population ("stickers"). The second type which occurred less frequently than the first consisted almost entirely of free-floating "non-sticker" cells. Although patients with this second type of growth pattern almost invariably had AML, 44% of AML's produced monocytoid "sticker" cells in culture. Cells from the majority of patients with ALL did not grow in culture.


Gilles de la Tourette's syndrome: biochemical approaches. Haloperidol, a dopamine receptor blocking agent, is the most effective therapy for Tourette's syndrome. In five patients with Tourette's syndrome, we found in the CSF an elevated probenecid-induced accumulation of HVA, the major metabolite of dopamine. This supports the hypothesis that Tourette symptoms are related to an increased firing of dopaminergic neurons in the central nervous system; haloperidol relieves these symptoms by blocking dopamine receptors. Some similarities of Tourette's syndrome to Lesch-Nyhan's syndrome prompted us to compare these two disorders, obtaining data from a large number of Tourette patients. In a questionnaire completed by 114 patients with Tourette's syndrome, the incidence of self-destructive behavior was 43%, a family history of gout or hyperuricemia was present in 27%, and 11% had a family history of Tourette's syndrome or tics. We propose that Tourette's syndrome could be a genetic disorder of purine metabolism which may result in neurotransmitter abnormalities such as an increased brain dopamine turnover.


[Functional anatomy and terminal tubules of Stensen's duct]. The dynamic anatomy of STENSEN's duct is somewhat different from what is usually accepted. GUERRIER, COURBIER and FRANCHEBOIS had indeed admitted that the buccinator msucle acted as a passive sphincter, without however mentioning the presence of terminal siphons and canalar valvules and without drawing particular attention to their dynamic relationship. This duct should not be considered inert, as part of a theoretical bayonet-like pathway which is more topographical than functional: the buccinator muscle and STENSEN's duct with its valvules and terminal siphons should be considered together as forming the real salivation apparatus.


[A salivary cyst and parotitis].

[A salivary cyst and parotitis]. The authors describe a case of upper left genital tumefaction whose development was protracted caused by a cystic lesions of the masseteric lobule of the left parotid gland with a background of parotiditis. It was cured by total parotidectomy with conservation of the facial nerve. Pathogenetic, clinical and therapeutic conclusions are deduced.


[Effect of insulin on the development of the tooth germ in mice]. After recalling the interactions affecting dental differentiation, the authors analyze the effects of various concentrations in insulin on dental rudiments cultivated in vitro. They found: an oedema causing histological lesions, no anticipation of cell differentiation or stimulation of collagen secretion, a decrease in mitotic activity but stimulation of thymidine 3H incorporation after short contact times.


[The temporomandibular joint in the newborn infant. Oto-meniscal relations]. Although they are anatomically immature at the time of birth, the temporomandibular joints are able to ensure efficient suction due to the branchial blastema interposed between the two articular nuclei. This conjunctive formation is the principal factor in the constitution of the meniscus and its frena, the articular surfaces, the capsule and the ligaments. This constitutes not only an embryological but also a functional entity. The joint runs the risk of paying heavily for this functional availability, by its relationship with the ear-drum which is a potentially infectious cavity. In fact, at birth there is still evidence of the original branchial continuum between the unknit tympanal and squamosal in the shape of the posterior meniscal frenum, the conjunctivo-vascular isthmus which puts the vascularization of the mucosa of the ear-drum in communication with the very rich vascularization of the neonatal temporo-mandibular articulation. Therefore, 1/3 of the so-called congenital temporo-mandibular ankyloses, apparently without cause, could probably be explained by the otomeniscal relationship existing in the new-born baby and continuing during the first few months of life in the atmosphere in the form of a conjunctivo-vascular link.


[10 years of maxillofacial traumatology in a hospital center]. The authors describe 315 cases of total maxillo-facial fracture and the conclusions to be drawn from them: --Endobuccal and orthopaedic surgical treatment under general anaesthetic, the osteosynthetic material being perfectly well tolerated: less than 3% having to be removed. --Treatment requiring a careful pre-operative radio-clinical assessment which can never be adequately carried out in an emergency, therefore treatment is delayed (5th and 8th days) except in cases of special emergency (wounds). --Delayed sequelae, bearing in mind the often spectacular lesions, are relatively rare.


[Microscopic anatomy and muscle architecture of the commissure of the lips in the newborn infant and the adult]. The muscular structure of the commissura of the buccal orifice in humans confers on it a special significance. It consists of two layers each apparently having a well-defined function. Deep layer. Quite distinct at the embryonic stage, it develops rapidly in the new-born. It consists of the internal orbicular muscle, or Poirier's sphincter oris, and the two buccinator muscles. This layer, of functional importance for digestion, is formed by a central sphincter surrounded by two cavitary muscles. In the new-born, it forms a real suction apparatus. From this point of view, the internal orbicular and the two buccinator muscles are the equivalent respectively of the circular and longitudinal fibres of the muscular digestive tunic. This layer is more cavitary and sphincteral than platysmal. Superficial layer. Platysmal, muscular it is dependent on the cephalic superficial fascia, it is mimetic. This layer is made up of platysmal muscles converging on the commissura. The labial muscular network of the platysmal muscles forms the external orbicular. This layer, which is rudimentary in the new-born, develops during growth alongside relationships (mimic-phonation). It appears complete in adults. Facial superposition and commissural fusion of the deep and superficial layers confer a dual function of the buccal orifice: --digestive by means of the deep sphinctero-cavitary layer, --mimetic by means of the superficial platysmal layer. Wilst growth is taking place, the digestive layer in fact assumes mimetic function and the platysmal layer may intervene at will in the functioning of the digestive sphincter. The commissura labiorum is the anatomical site at which the cutaneous and digestive coats converge. Briefly, the buccal orifice is a digestive sphincter complete with mimetic function. Has not the face become a cortical organ in the course of evolution?


[Influence of the soft palate on tongue statics and mandibular growth. Therapeutic conclusions]. The soft palate has a major influence on mandibulo-lingual statics. Thus in the case of congenital cleft palate, there is in general glossoptosis with mandibular retrognathia. Conversely, palatal shortening may be associated with functional mandibular prognathia which it is possible to correct by urano-staphylo-pharyn-goplasty, if carried out sufficiently early. In many cases of mandibular prognathia the soft palate has a special shape and orientation. The problem is to know whether this appearance is secondary to the dysmorphosis or partially responsible for it.


[Permanent jaw constriction of extra-articular origin]. The authors describe a new case of permanent constriction of extra-articular osseous origin. They consider the classical distinction between constrictions due to traumatism and those due to malformation (O. Jacob's disease) debatable, for this malformation is usually secondary to traumatism. They also think that the osteoma responsible for constriction may be considered a localisation of neurogenic para-osteoarthropathies.


[Inclusions of salivary gland tissue in the mandible, various locations, pathogenesis]. In connection with three cases of their own, the authors recall the radiological signs of this entity isolated by Stafne in 1942. They demonstrate that this picture of the mandibular angle or of the premolar area is quite characteristic and suggestive and usually makes diagnosis possible. They show that the inclusion is always of normal salivary glands corresponding to the gland opposite the cavity: sub-maxillary for the angle, sublingual for the premolar area. They prefer the pathogenetic theory that it is an error in development during embryogenesis of the pelvi-lingual sulcus and of sub-maxillary and sublingual gland formation.


[Bacteremia following tooth extractions]. A study was made of the incidence and nature of bacteremia occuring after extractions in a group of 189 patients hospitalised in the maxillo-facial surfery department of Iassy. The figure of 65.5% positive blood cultures demonstrates the particular role of dental extraction in the pathogenesis of bacterial endocarditis. Antibiotic sensitivity studies of streptococci, the bacteria isolated most frequently, showed their remarkable sensitivity to penicillin and erythromycin (95.9%) and their remarkable resistance to streptomycin (83.8%). This would indicate penicillin to be the antibiotic of choice in the treatment of post-extraction bacteraemia, replaced by erythromycin in individuals allergic to penicillin. Study of the relationship between the incidence of bacteraemia and the number of teeth extracted indicates the possibility of grouping several extractions at the same session, thereby reducing the period of administration of antibiotics as a "cover". As far as the type of anaesthesia, local or general, was concerned, the higher level of post-extractional bacteraemia in patients who had received a general anaesthetic suggests that loco-regional anaesthesia should be the method of choice.


[Comparative clinico-histologic study of metastatic adenopathies in cancer of the lip]. The authors studied the correlation between clinical examination and histological findings in lymph node metastasis in 256 patients suffering from carcinoma of the lip. According to the clinical stage, the following were encountered: a) 84 cases of nodes without any clinical changes (32.8%); b) 140 cases of nodes larger than normal, but mobile (54.6%); c) 32 cases of fixed nodes (12.6%). Lymph node dissection was carried out in 210 patients and histological examination revealed: --in group (a) 61 patients operated): lymph node involvement in 8.9% of cases; --in group (b) (120 cases operated): lymph node involvement in 30% of cases; --in group (c) (29 patients operated): lymph node involvement confirmed in 86.2% of cases. In conclusion, only histological examination provides definite information regarding lymph node involvement, confirming or contradicting pre-operative clinical findings.


[Etiologic problems posed by cervicofacial cellulitis]. A diffusing and lingering cellulitis is followed two months later by a right coxitis. Recovery of the coxitis and of the cellulitis is obtained by the antituberculous treatment. Authors demonstrate the possibility of the tuberculous etiology of the cellulitis.


[Traumatic intracranial penetration of the mandibular condyle]. The authors report a case of severe multiple trauma in which, as a result of the large number of complex injuries together with necessary therapeutic measures, the intra-cranial penetration of the mandibular condyle was unnoticed during the first months following the accident. They emphasize the discordance between the anatomical lesions and their clinical manifestations. Thus a complete radiological examination is necessary at a secondary stage in order to detect such lesions which, by contrast to that which might be supposed, are not obvious clinically. As far as treatment is concerned, rather than resorting to orthopaedic menoeuvres with imprecise traction and which, in any case, fail to resolve the entire problem. the authors recommend a combined maxillo-facial neurosurgical operation.


[The phantom mandible].

[The phantom mandible]. The authors report a case of "phanton mandible" (phantom bone, disappearing bone, massive osteolysis affecting the mandible), describing the clinical colrse and radiological appearance of the condition. From a diagnosis of non-specific osteitis of the premolar region, they observed their patient until there was virtually total disappearance of the osseous structure of the mandible. Studying the world literature, they have collected 11 cases of the disorder involving the mandible, and, in some cases, the facial skeleton. They distinguish this condition from senile atrophy of the mandible and, after histological study, feel that it is not possible to classify this case in the context of Gorham's disease: in fact, haemangiomatosis was proved histologically in only three of the eleven cases described in the facial area.


[Multiple injuries and multiple methods of resuscitation]. The aim of treatment in the trauma patient is the surgical repair of all traumatic lesions in as short a time as possible, using standard techniques and at the same time if possible. Such surgical intervention may rarely be essential for survival (internal haemorrhage, extradural haematoma), but is almost always an essential factor in the functional and aesthetic result obtained. Thus everything should be combined to fulfill this objective. Picking up of the injured, resuscitation at the site of the accidentation and the quality and appropriate orientation of transport are of obvious importance from this standpoint and it is easy to understand that first efforts must lie here.


[EEG and craniofacial injuries].

[EEG and craniofacial injuries]. The number of cases studied was too small to be really representative of the role of the E.E.G. in the assessment of cranio-facial trauma cases. The following points may nevertheless be stressed: -The usefulness of negative findings. The E.E.G. may be used to confirm that a purely facial impact, or one without any severe cranial involvement, has only minor or quite negligeable cerebral repercussions. -The presence of significant E.E.G. changes indicates marked cerebral involvement. The nature of the latter (contusion, haematoma etc.) cannot be determined by the E.E.G. alone but any obvious localising signs (e.g. severe frontal deterioration) should indicate the possibility of a lesion requiring urgent neurosurgical treatment. In particular, sub-frontal extra-dural haematomas are associated with abnormalities clearly localised in the fronto-polar regions (R. Vigouroux et al., 1962). Apart from such specific collections, the type of damage described in operative reports easily explains the major disturbances in the frontal tracing which are almost invariably encountered. -The value of an early E.E.G. examination and of repeated studies. The first record gives an indication of the cerebral "state" and of possible "functional" disturbances which may exist later after the accident. Above all, it represents a valuable prognostic indication, in particular in patients who are in coma, precisely reflecting the depth of the latter and its potential reversibility. The course and progress of initial abnormalities is also an element in prognosis. In our patients, it was surprising to note the ease with which certain initial major disturbances resolved. However the persistence of minor alterations should lead to reserve with regard to the recovery of complete cerebral integrity and such subjects should be carefully followed up.


[Neurosurgical indications in craniofacial injuries]. The cerebral complications of cranio-facial trauma require urgent neurosurgical assessment and intervention. Apart from such cases, the cooperation of the neurosurgeon is also necessary when the anterior part of the base of the skull must be explored. This may be necessary either in the presence of a cerebrospinal fluid leak with rhinorrhoea or because the reduction and fixation of orbito-facial fractures requires an intracranial approach. Early treatment, at the same time, of all cranial, basal and orbito-facial lesions is recommended.


[Echography and cerebral gammagraphy in craniofacial injuries]. The authors review the aid provided and sometimes essential nature of echographic and isotopic studies in cranio-facial trauma when seeking neurological complications -in particular intracranial haematomas and cerebrospinal fluid fistulas. They describe the principles of each of these technics, their indications, performance and limitations. These examinations are simple, rapid and perfectly harmless but must be carried out in specialised departments, which limits their use.


[2 cases of malphigian epithelioma of the parotid gland]. The authors describe two cases of squamous cell carcinomata. Neither the localisation on the anterior border, neither the evolution seems common. A histochemical and electronmicroscopical investigation of different fragments achieves their study.


[The frontomaxillary suture. Theoretical bases and general principles of the application of postero-anterior extraoral forces to the orthopedic mask]. Each maxilla is joined to the frontal bone by a veritable fronto-maxillary sutural joint which, in the young subject, permits sliding movements. During growth, the maxilla orients itself in relation to the mechanical effects of the various structures which surround it. The location, below the frontal sinus, of this joint endows it with special properties of resistance and change in position of orientation. These anatomico-functional peculiarities explain certain results obtained by classical heavy antero-posterior of postero-anterior extra-oral forces.


Differentiation of odontogenic tissues in organ culture. Molar tooth germs from 17-d-old mouse embryos were cultivated in a Trowell-type culture, and different culture media were tested for their ability to support enamel formation. The medium which allowed secretion of considerable amounts of enamel matrix by ameloblasts consisted of BGJb medium supplemented with 20% horse serum, 10% chick embryo extract and 0.9 mM ascorbic acid. At the onset of culture the teeth were in the early bell stage. After 2 weeks of cultivation both odontoblasts and ameloblasts had differentiated, and considerable amounts of predentin and enamel matrix had been secreted. Similar development was also seen in teeth which had been enzymatically separated into the mesenchymal dental papilla and epithelial enamal organ and subsequently recombined in vitro. This method allows good differentiation of odontogenic tissues, and is considered suitable for further studies of tissue interactions in the tooth rudiment.


Changes in the water permeability of palatal mucosa after complete denture treatment. The water permeability of the human palatal mucosa has been studied in 12 persons with 1 year of full maxillary denture experience and 10 persons without dentures. Transmucosal water transport rates were studied gravimetrically with the use of solutesaturated discs of filter paper in contact with the mucosa, in accordance with earlier described procedures (KAABER 1973a, b). The inflow of water through clinically healthy mucosa was at the same level in both groups. After use of a 1.10 mol sucrose solution a significant increase in the inflow was observed in the denture wearers group, which suggested an increased amount of osmolytes in the mucosal surface. Two denture wearers with a slightly inflamed mucosal surface showed an increased inflow after use of water and a corresponding strong outflow after use of the sucrose solution, indicating a partial loss of the mucosal barrier function.


Less dental caries among secretors than among non-secretors of blood group substance. Salivary mucins can aggregate oral bacteria and also constituents of pellicle and plaque. A,B, and H blood group antigens are present on the mucins of secretors only. These mucins have also been shown to contain more carbohydrate than non-secretor mucins. The aim of the present study was to relate these genetically determined differences in mucin composition to caries prevalence. Data on blood group, secretor status, and caries prevalence were collected from 69 dental students. In all blood groups, the average caries prevalence was lower for secretors than for non-secretors. The difference was more pronounced for smooth surface than for total surface prevalence. The secretors of blood group mucin A had the lowest caries prevalence. The results would be consistent with an impact of the mucin composition upon the caries prevalence, and possible mechanisms are discussed.


Root caries: distribution and uptake of elements in lesions adjacent to silicate or amalgam restorations. In carious lesions adjacent to silicate or amalgam restorations outer lesions of the cementum showed the same content and distribution of Ca, P, Mg, and S as did primary lesions in this area, but differed from these in having an increased content of Zn, Al, and probably F (silicate cases) and Zn, Sn, and Cu (amalgam cases). The cementum walls showed an uptake of ions largely similar to that previously described in dentinal walls.


Relative effects of sucrolytic enzymes in human dental plaque. The relative effects in human dental plaque material from the three main extracellular sucrolytic enzymes from bacterial origin, invertase, dextransucrase and levansucrase, have been investigated by means of quantitative determination of products with sucrose as the substrate. Twenty young men having carious lesions and harboring plaque material on the tooth surfaces, were selected. One gram (wet weight) of plaque material was obtained and divided in five samples, 0.2 g each, for different investigations and controls. Twice as much fructan as glucan was found in plaque. Invertase activity was found to dominate sucrolysis within plaque with 99.67% of the total activity.


Permeability and fluoride release of lining materials containing amine fluorides. The addition of amine fluorides to a copal recin (Copalite) and a chlorine caoutchouc varnish (Pergut S-40) has been studied. The permeability of Copalite films was only slightly increased whereas the excellent film-forming qualities of Pergut S-40 were destroyed by the addition of fluorides. A high fluoride release was found initially from test films of the materials but within 2-3 weeks a decrease to very low fluoride levels was observed.


Fluoride uptake from restorative dental materials by human enamel. The purpose of the study was to determine the uptake in vitro of fluoride from restorative materials by tooth enamel and whether prior etching of the enamel causes a change of uptake. The outermost layer of the labial surface of extracted canines was removed by grinding and the enamel was covered with five different fluoride-containing materials; a silicate, a composite resin, an amalgam, a silicophosphate, and a polycarboxylate luting cement. The material was either removed immediately or after storing the tooth in distilled water. The fluoride content was determined using a sensitive physical method based on the 19F (p,alpha gamma) 16 O reaction. In addition, the fluoride content of enamel after etching for different periods of time and of etched enamel which had been in contact with silicate cement was determined. The mean fluoride content of uncovered interior enamel was 226 parts/10(6). All materials, except the composite, increased clearly the fluoride content of the underlyaing enamal. Etching of interior enamel also increased the fluoride values. No difference could be shown in fluoride uptake from silicate and composite resin between etched and unetched enamel.


An infrared spectroscopic study of sealants. The aim of this work was to determine the quantity of remaining unreacted methacrylate groups in polymerized dental sealants. Eight brands of sealants were investigated by means of a grating infrared spectrophotometer. The infrared absorbance measurements were made before polymerization and repeated after the sealants had been polymerized at 37 degrees C for 24 h. The quantities of remaining unreacted methacrylate groups were determined and the data expressed as percentages of the total amount of methacrylate groups in the unpolymerized materials. The results demonstrate that commercially available sealants exhibit different degrees of conversion 24 h after the start of polymerization. The quantities of remaining methacrylate groups after polymerization under conditions comparable with optimal clinical conditions range from approximately 15% to approximately 35% in the different brands.


Evaluation of fissure sealing with a diluted composite sealant and an UV-light polymerized sealant after 36 months' observation. The idea of fissure sealing has found wide acceptance in caries prevention. The present investigation was initiated to evaluate the retention of a diluted composite material used as a fissure sealant, compared with the retention of an UV-light polymerized sealant. After an observation period of 3 years, it seems justified to assume that a diluted composite sealant is a fully acceptable alternative to an UV-light polymerized sealant, and the former material seemed to have some advantages: a simpler polymerization procedure, an apparently better wear  resistance due to ceramic filler particles, and an easier recognition because of a slight discoloration.


Lipids in the walls and contents of jaw cysts. The amount and composition of lipid in 129 walls of jaw cyst and 18 pieces of cyst contents was determined by thin-layer chromatography. The proportions of the fractions (i.e. phospholipid, free cholesterol, cholesteryl ester, triglyceride, free fatty acids) were compared with corresponding values (collected from the literature) from the superficial layers of normal and atherosclerotic aortas. The amounts of total lipid and of the fractions were comparable. Concomitant with an increasing amount of lipid, there was a rise in the ratio: total cholesterol/phospholipid. In the aortic lesions this increase of cholesterol was due to a rise in the fraction of cholesteryl ester. In the cyst material, the increase was due to a rise in the free cholesterol. A possible explanation is discussed.


Lysozyme activity and flow rate of mixed saliva in children, adolescents and adults. Reports of lysozyme activity in mixed saliva differ greatly from lysozyme determination in pure form. In this study lysozyme activity of mixed saliva was determined by turbidimetric method in healthy children, adolescents, and adults, 111 subjects altogether. The salivary flow rate was estimated. The lysozyme activity of mixed saliva in 24 children was 129.4 +/- 42.4, in 21 adolescents 160.9 +/- 58.2, and in 66 adults 165.7 +/- 36.7 (mug/ml hen's egg white lysozyme). The flow rate of mixed saliva was similar in different groups. No statistically significant linear dependence between saliva lysozyme and flow rate was found. The lysozyme activities obtained correspond with the results of saliva lysozyme in pure form.


Leukocytes in the edentulous mouth.

Leukocytes in the edentulous mouth. Oral leukocytes were estimated in 55 edentulous persons wearing dentures by sequential mouthrinses. Forty-four subjects had clinically healthy-looking mouths and 11 had parital mild inflammation under the dentures. Leukocytes were found in the mouths of all subjects. The migratory rate in 30 sec in 44 subjects was 0.283 +/0 0.082 X 10(6) and in 11 subjects 0.570 +/- 0.147. The difference between the two groups was highly significant, P less than 0.001. The cell counts of the healthy edentulous mouth are comparable with the healthy dentulous mouth. The unexpected results raise the question of the origin of leukocytes in the edentulous mouth.


Elastic properties of resin-based filling materials. Some aspects of the viscoelastic behavior of resin-based filling materials have been studied by the use of a bending test. The specimens, designed as cantilever beams were loaded for 30 sec and then unloaded. The tests were performed at 1/2 h, 1 h, 3h, 24 h, and 1 week after mixing of the materials. The strains were measured by electric strain gauges cemented to the tensile side of the beam. Six products were tested, five of them composites. Different brands of materials showed considerable variation in degree of viscoelastic behavior. The value for elastic after-effect decreased markedly with time, reaching a fairly constant value at 24 h. Elastic moduli showed a similar increase and the stiffest materials exhibited the least elastic after-effect.


Marginal fracture of dental amalgams.

Marginal fracture of dental amalgams. The purpose of this study was to determine the marginal fracture of different amalgams, using a semiclinical method which facilitates standardization and minimizes the observation time, in 10 patients receiving complete dentures. Cavities were cut occlusally in acrylic premolars and molars. The margin was then beveled to 45 degrees with a cone-shaped diamond. Two dispersion-strengthened amalgams and one conventional amalgam were used in each mouth. The cavities of each quadrant were filled with the same amalgam. Thus, conventional amalgam fillings were always placed in opposing quadrants to those filled with a dispersion-strengthened amalgam. The degree of marginal fracture was evaluated from the prints (magnification X 5-7) by five dentists separately and blindly. After 6 months' service, severe marginal fracturing was frequently seen.


Opinions among Norweigian dentists on specialization and/or general practice. Three special areas of dental practice are recognized by the Norwegian Dental Association: oral surgery, orthodontics, and periodontics. A representative, nationwide sample comprising 50 dentists in Norway was surveyed through personal interviews concerning opinions about specialists and further specialization. Two dentists in the sample were specialists, the remaining general practitioners. Two-thirds of this group thought that the specialization of dentistry would continue. Only 11 dentists, however, considered this development to be desirable. Every second stated nevertheless that there was a shortage of specialists, particularly orthodonists, in the district where they practice. Most respondents had good experiences cooperating with specialists but they were against astablishing new specialities; they were concerned about their own scope of acitivity. Some pointed out that it requires greater skill and ability to be a solo general practitioner in a rural district than to be an urban, centrally located specialist. However, only 13 dentists considered it right to make general practice a "specialty".


Classification of written examinations in dental education in Norway according to educational aims. The purpose of the present study was to assess to what extent retention of factual knowledge or higher cognitive abilities, such as analytical/critical evaluation, were required by the students in the written examinations in clinical departments of dental schools in Norway in 1973-1975. A modified version of Bloom's taxonomy of educational objectives was used to classify the examination questions. Most of the questions were covered by the teaching program and concerned factural knowledge. When clinical examinations included a complete patient history and/or radiographs, judgment of the available information was demanded from the students. A great number of minor questions usually represented a lower taxonomic level than the use of a few essay questions.


The morphology of dyserythropoiesis in a patient with acute erythroleukaemia associated with multiple myeloma. A patient with multiple myeloma in whom acute erythroleukaemia developed 5 years following treatment with irradiation and melphalan is reported. Immunoglobulin synthesis and immunofluorescence investigations provided evidence that the blast cells in the peripheral blood did not belong to the plasma cell series; ultrastructure examination demonstrated their myeloid origin. Chromosomally abnormal cells were observed in both the bone marrow and peripheral blood. Light-and electron microscopy of erythropoiesis in this case showed distinct features of dyserythropoiesis, similar to those described in other entities. The erythroid cell abnormalities are discussed in the light of their being either indications of malignancy or of a reactive process.


The antianabolic effect of tetracyclines in a consecutive clinical series. In a series of 58 tetracycline-treated patients from an intensive care unit 33 patients were given oxytetracycline and 25 patients were given doxycycline. In 50 of the patients the serum creatinine level never exceeded 2 mg/100 ml. The serum urea/creatinine ratio was repeatedly determined in all patients. The oxytetracycline group displayed significantly higher mean values for this ratio during treatment than the doxycycline group. This was interpreted as a probable antianabolic effect due to the oxytetracycline therapy.


The penetration of doxycycline into CSF. After single oral or intravenous doses of doxycycline the concentrations found in the spinal fluid did not exceed 0.1 mcg/ml. Daily oral administration for 2-10 days gave a level in the spinal fluid of 0.1-0.76 mcg/ml. The mean value, 0.37 mcg/ml, corresponded to 14% of the concentrations found in serum. Further studies of the penetration of doxycycline in patients with a damaged blood-brain barrier should be performed before doxycycline can be recommended for the treatment of CNS-infections.


Studies on the excretion of doxycycline in patients with ileostomies. The excretion of doxycycline was studied in patients with ileostomies after intravenous administration of the drug. The intestinal excretion, measured by bioassay, was of the same magnitude as reported in normal human beings when similar methods have been used. If the main part of a dose of doxycycline is secreted and bound in the intestine, this study suggests that the large bowel is not important for this binding.


The elimination of tritiated doxycycline in normal subjects and in patients with severely impaired renal function. Tritiated doxycycline was administered to four normals, four patients with renal failure interdialysis, and three patients in renal failure who were not on dialysis. Elimination was followed by collection of urine and feces up to eight days. It was demonstrated that renal failure reduced the urinary excretion of doxycycline. In normal individuals the total of 86% of the radioactivity was eliminated in five days, half in the urine and half in the feces. In patients, with renal failure on dialysis, 32% of the radioactivity was eliminated in that time, 9.3% in the urine and 23% in the feces. In renal failure patients not on dialysis 49% was eliminated in that time, 4% in the urine and 45% in the feces; when followed up to eight days a total of almost 70% of the radioactivity was eliminated and the increase elimination was accounted for by fecal elimination such that 64% was eliminated in the feces and 5% in the urine. The disappearance from the plasma compartment in all three groups was similar. Thus, although the plasma half-life of doxycycline is not significantly prolonged in renal failure, it appears likely that the drug is taken up into a compartment from which it may slowly be eliminated and when followed for a continual period of time a significant percentage can be recovered from the feces. There remains however, up to 30% of the administered dose which was not recovered and it must be assumed that a significant per cent of doxycycline would accumulate in a compartment, as yet unidentified, in patients with renal failure.


Concentrations of doxycycline in human seminal plasma. Single oral doses of 200 mg doxycycline was given to 16 healthy test subjects. The concentrations of the drug were measured in blood plasma and seminal plasma and related to the zinc content. Measurable concentrations of doxycycline were obtained in seminal plasma one to two hours after drug intake. The maximum level was reached after 4 to 6 hours and measurable concentrations were recorded in both blood plasma and seminal plasma after 24 hours. This means that measurable concentrations were maintained during almost the entire dose interval. In split ejaculate experiments it was shown that doxycycline is excreted mainly through the prostate gland. The mean concentration ratio for "prostatic fluid" vs. blood plasma in healthy volunteers was about 0.6. Indirect evidence is presented that the concentrations in the fluids from the accessory genital glands are higher if patients with prostatitis are given daily doses of 100 mg doxycycline.


Tetracyclines, doxycycline and calcified tissues. The use of radioactive isotope techniques has led to a thorough re-assessment of our knowledge of bone histology. It is known that tetracyclines faithfully follow the pattern of calcium metabolism in the body. Fluorescence microscopy, after double labeling with tetracyclines and alizarin red S, is very useful for collection of qualitative and quantitative data on compact and spongy bone remodeling. Two illustrations are presented which demonstrate how oxytetracycline and doxycycline administered in therapeutic doses to growing dogs, become deposited in the dentine. The significance of these findings is discussed.


A computerized study of bacterial resistance patterns (1971-1974). A preliminary report. In an effort to provide information concerning the bacterial sensitivities in the Dordrecht area, continuing surveys are performed on the laboratory results. In 1974 information was presented on the bacterial sensitivities and resistance patterns during the period between 1968 and 1970. It has now been possible to study data from 1971 to 1974. Approximately 4000 sensitivity reports were surveyed--1000 from each year. A transfer sheet which could be entered into a computer was filled in for each patient who had a bacterial isolate and an antibiotic sensitivity test. This report gives the results of the survey. It is concluded that specific antibiotic testing must be performed. As an example more strains are sensitive to doxycycline than to tetracycline.


Bacteriological findings in sinusitis (1963-1975). Two different studies were performed in order to determine the role of aerobic and anaerobic bacteria in sinusitis. Aerobes: A retrospective study of 331 cases of all types of sinusitis (from 1963 till 1975) showed an increasing occurrence of Haemophilus influenzae during the last three years. Only in the acute sinusitis is Streptococcus pneumoniae more frequently found than Haemophilus influenzae, which exhibits the highest occurrence in chronic and undeterminable cases. We found cultures with pathogenic aerobes in 64% of the acute and 56% of the chronic cases of sinusitis. Anaerobes: A prospective study of 100 sinus secretions from 66 patients with paranasal sinusitis showed the great importance of anaerobes; they were present in 33% of samples, pure anaerobic cultures in 12% and mixed aerobic-anaerobic in 21%. Peptostreptococcus sp. showed the highest occurrence (15%). Anaerobic sinusitis is more frequent in unilateral cases. The presence of anaerobes is not dependent on the patient's age or the duration of the sinusitis. In 76% the anaerobes disappeared after the initial antral irrigation.


Isolation of Chlamydia in acute salpingitis. In 22 patients with acute salpingitis, verified by laparoscopy, samples for attempted isolation of bacteria, Mycoplasma and Chlamydia were drawn from aspirates and cervical smears. CF-antibodies to Chlamydia were measured to acute and convalescent phase sera. Anaerobic bacteria were isolated from tubal secretions in two patients and Mycoplasmas in one patient. In two patients Chlamydia were recovered from the Fallopian tube. The serological investigation indicated Chlamydia infection in 6 patients.


Ultrastructural studies of rabbit synovitis induced by autologous IgG fragments. II. Infiltrating cells in the sublining layer. The synovial sublining layer of rabbits with synovitis induced by intra-articular injection of cathepsin D digested autologous IgG fragments (Fab2) has been examined under the electron microscope. Twelve or more injections of autologous Fab2 led to chronic synovitis with dense mononuclear cell infiltrates containing lymphocytes, blastic cells, plasma cells and macrophages. In the infiltrates there was evidence that the lymphocytes had been activated prior to transformation into mature plasma cells. Indirect evidence suggests that T lymphocyte activation also occurred in these infiltrates. Cellular contacts between macrophages and lymphocytes or plasma cells as well as between M cells and lymphocytes were demonstrated. These contacts are tentatively interpreted as a feature of ongoing immune processes in the synovium.


Ultrastructural studies of rabbit synovitis induced by autologous IgG fragments. I. Proliferation of the lining cells. The synovial lining cells of rabbits with experimental synovitis induced by intra-articular injection of cathepsin D-digested autologous IgG fragments (Fab2) have been subjected to electronmicroscopic study. From 3 to 50 such injections resulted in hyperplasia of the lining layer with an increase in the numbers of phagocytic and synthetic cells. Morphologically the phagocytes were classified into monocyte-like cells, mature and immature phagocytes, and epitheloid=like cells, indicating that synovial M cells may originate from blood monocytes that differentiate in situ like the monocytes in other tissues. The finding of "undifferentiated" (mesenchymal), transitional and mature synthetic cells in the lining layer suggests that synovial F cells are derived from the undifferentiated mesenchymal cells persisting in the synovial membrane in postnatal life. In the animals with synovitis, the synthetic cells were found to undergo mitosis but not the phagocytic cells. It is concluded that the hyperplasia of the lining layer is due to two distinct processes, namely invasion by precursors of M cells (monocytes) and local proliferation of F cells. As far as immune reactions involved in the synovitis are concerned, the possible roles played by lysosomal substances in these two processes are also discussed.


[The treatment of acute myelocytic leukemia during the first recurrence by means of a new cytostatic combination]. Fifteen patients with acute myeloic leukemia in the first relapse following initial therapy were treated with a combination of adriamycin, vincristine, 6-thioguanine and the new podophyllotoxin derivative VP 16-213. Complete remission was obtained in 3 cases and partial remission in 3 further patients. The combination was generally well tolerated. These preliminary results are compared with those available in the relatively meagre literature. The study is being continued.


[Immunologic aspects of granulocyte transfusions]. Immunologic problems appear to have a fundamental bearing on the survival of transfused white blood cells. Detailed study of HLA and non-HLA antigens of granulocytes and a systematic search for transfusion-induced antibodies make it possible to evaluate the respective importance of the different antigenic systems. This should lead to better clinical tolerance and optimum therapeutic effectiveness of granulocyte transfusions.


[Circulating immune complexes in human leukemias]. Occurrence of immune complexes in leukemia has been investigated by the 125I-Clq-binding test. A highly significant serum Clq-binding activity (Clq-BA) was demonstrated in 37% of patients with acute myelocytic leukemia, in 23% of patients with acute lymphocyte leukemia,and in 32% of those in blastic crisis of chronic myelocytic leukemia. Such a high Clq-BA is found only in 13% of cases with chronic leukemia. Incidence of increased serum Clq-BA is significantly higher during the blastic stage of leukemia than in complete remission. There is no correlation between the elevated Clq-BA and infections complicating acute leukemia, or with the chemotherapy given to the patients. The Clq-binding material exhibits properties similar to those of immune complexes.


[Triple Philadelphia chromosome during blastic crisis of a chronic myelocytic leukemia]. The blastic phase of a Ph1-positive chronic myeloid leukemia (CML) is often characterized by hyperdiploidy and sometimes by the presence of a double Ph1, suggesting a pattern of clonal evoluation. In the case reported here, the caryotype at the time of diagnosis in 1970 was 46, XY, Ph1. In 1975, after a blastic evolution followed by a drug-induced hematologic remission, cytogenetic studies revealed a chromosomal mosaic: 47, XY, 2 Ph1 and 51, XY, 3 Ph1, 3 C, the clone with 3 Ph1 representing approximately 20% of the mitotic cells. Furthermore, with the Giemsa banding technique, it was possible to identify the 3 supplementary C chromosomes of the 51 chromosomes clone, as being an 8, a 9 and 9 q + respectively. This observation illustrates the succession of chromosomal anomalies occurring during the evolution of CML with, in this case, the unusual appearance of a clone with 3 Ph1.


Chronic myeloid leukaemia in South African blacks. A study on 25 South African Black patients with chronic myelogenous leukaemia (CML), who were followed for 3 1/2 years, is reported. The Ph chromosome was found in 19 of 20 patients studied. Males predominated in a ratio of 2,5:1. Several unusual clinical features were encountered: significant lymphadenopathy, congestive cardiac failure and skin lesions. Patients with lymphadenopathy responded to busulphan therapy no differently from patients without lymphadenopathy. Nine patients had congestive cardiac failure, and in 7 of these a cause could not be found. Three untreated patients became pregnant, indicating that CML per se does not cause infertility. The haematological measurements were similar to those of previous reports; however, the marked splenomegaly suggests that South African Black patients present themselves for treatment rather late in the disease. The median survival time of 34 months is similar to that of previous reports of larger series from other parts of the world.


Intracerebellar chloroma (granulocytic sarcoma): a neurosurgical complication of acute myelocytic leukemia. A discrete intracerebellar mass of myeloblasts was found in a 26-year-old woman with acute myelocytic leukemia in remission. This chloroma (granulocytic sarcoma) was treated successfully by surgical extirpation. An aggressive neurosurgical role seems appropriate in handling central nervous system leukemic nodules in view of the improved patient survival created by current chemotherapy regimens.


[The diffusion constant for water in dentin in extracted healthy juvenile teeth]. The authors point to the diffusion processes in dental hard tissues and describe a personal method for determining the diffusion constant in dentine. The diffusion constant in the dentine of permanent teeth from adolescents is 0.74 - 10(-2) cm2/d, measured by means of radioactively labelled water. The necessity for further studies is emphasized.


[Determination of the time of mineralization of the dental hard substances in rabbits]. On the basis of radiographic studies on animals (rabbits), the authors determined the beginning of bone and dental hard tissue calcification. First signs of ossification were observed on the 17th day after copulation, whereas the calcification of the incisors began only on the 19th day after copulation.


[Filling therapy with special reference to experimental studies on model-cast inlays]. By way of introduction, the authors report the results from clinical and radiographic examination of teeth with inlays restorations. In view of further corroboration of the clinical results with modelcast inlays, the authors measured the marginal adaptation of inlays made of Goplat 203 and Sena 65, respectively. The difference in the average marginal adaptation between Goplat 203 and Sena 65 is insignificant, amounting to 3.6 mum in favour of the gold alloy, which permits to recommend Sena as a casting alloy for posterior teeth.


[Possibilities of in vivo identification of various types of fissures in human teeth]. In consideration of the fact that the results from the visual appreciation of the fissures in freshly extracted teeth agree with the findings from thin sections of the same teeth, the authors developed a stereomicroscopic method for assessing in vivo the occlusal surfaces of human teeth. The great percentage of accurate assessments of wide fissures obtained with this method permits to recommend it. Narrow fissures may be ascertained by exclusion.


[In vivo measurements of gingival thickness]. The substantiation of periodontal changes and the evacuation of their course must always involve exact measurements. Up to now the thickness of the gingiva and its dimensional changes have been neglected in most studies though such data may be very revealing in assessing the tissue. The author designed a device which permits to measure the recession of the gingiva with an accuracy of 1/10 mm and to determine exactly the thickness of the gingiva. The thickness of the gingiva was measured in a group of patients undergoing an oral irrigation cure. An initial soft-tissue reaction (in which the opening of terminal vessels and swelling processes seems to prevail over the flooding-out of oedemas) is followed by a small reduction in gingival thickness (presumably associated with the flooding-out of oedemas). The results so far obtained correspond to the clinical, stomatoscopical and bioptical observations.


[Results and consequences of clinical-radiological follow-up studies of root canal treated teeth. 2. Dependence of the results on age, degree of root canal obturation and devitalizing drugs. Conclusions for the dental practice]. The authors report of the follow-up examination of root-canal treatments performed at the Policlinic of Conservative Stomatology of the Karl Marx University of Leipzig in 1967, in which 499 teeth were assessed using severe criteria. The results obtained from the various diagnostic groups depended on the age and the degree of root-filling. Of the root-canal treatment techniques employed, devitalization by means of arsenic showed the highest failure rate. Conclusions relevant to stomatological practice are drawn from the results presented in the two parts of this study.


[Anxiety and stress in dental practice. 2. Results of studies in children]. The stressor effects of various dental procedures were studied in 85 children. In the group of children undergoing extractions, the highest average values for pulse rate and blood pressure were observed right before anaesthesia. Stress reactions occurring in filling therapy were, on an average, almost as frequent and as severe than those due to extractions. "Anxious" children responded to dental procedures more frequently with increased 11-OHCS excretion in the urine than "indifferent" children, but there was no significant difference in adrenocortical activity.


[Report on experiences in the planning and introduction of health educational and caries preventive measures]. The author deals with the organization and execution of a program of health-educational and caries-protective measures which concentrates upon nursery and primary classes. Propagation and great efficiency are aimed at not only by the collective work of all the members of the personnel of the stomatological facility but also by the co-operation with many societal forces.


Is congenital fibre type disproportion a true myopathy? The authors report a case of congenital fibre type disproportion in a 32-month-old male patient. A pathogenetic role of alcohol ("fetal alcohol syndrome") could be discussed here because the mother drank daily large quantities of alcohol during pregnancy. Histochemical features undistinguishable from those reported in congenital fibre type disproportion were also observed in two cases of globoid cell leucodystrophy (Krabbe's disease) and in one case of infantile acid maltase deficiency (Pompe's disease). Morphometric studies confirmed this analogy. The occurrence of a similar fibre type disproportion in conditions so completely different from each other casts doubts as to the specificity of these histoenzymatic features. It is suggested that at least some cases of congenital fibre type disproportion could result from a maturational insufficiency of type I motor neurons or from a damage brought to the Schwann cells.


Turku sugar studies. VII. Principal biochemical findings on whole saliva and plaque. Plaque and whole saliva samples of the subjects of the Turku sugar studies were analyzed for several enzymes and biochemical compounds. Strict xylitol diet maintained throughout the study a 50% lower quantity of plaque than the sucrose of fructose diets. Decreased plaque and whole saliva lactate concentration, diminished activity of salivary amylase, and reduced hydrolysis rate of sucrose in plaque and whole saliva were observed in relation to xylitol consumption. The xylitol diet also reduced the ratio of glucose to proteins in plaque. On the other hand, increased activity in plaque of alpha- and beta-glycosidases (against p- and o-nitrophenyl derivatives), fucosidase and aspartate transaminase, as well as increased activity of proteinases and lactoperoxidase in saliva were found in connection with xylitol consumption. The fructose diet caused less clear differences when compared to sucrose, but the experiments indicated a selectivity of the effects of dietary carbohydrates on the biochemistry of whole saliva, plaque and salivary glands. The results contribute in explaining the cariostatic effects of xylitol and the lower coriogenicity of fructose when compared to sucrose.


Turku sugar studies. VIII. Principal microbiological findings. The possible qualitative and/or quantitative alterations in the proportions of cultivable groups of oral microorganisms were analysed during a clinical trial involving the consumption of fructose (F) or xylitol (X) in comparison to sucrose (S). Supragingival plaque samples and paraffin-stimulated saliva were collected from 115 subjects. The samples were dispersed by sonication, diluted stepwise, plated on blood sugar, Mac Leod agar, Mac Concey agar, Rogosa S.L. agar, and Sabouraud agar plates and incubated anerobically and/or aerobically. The number of the total colony forming units (CFU) on blood agar plates in anaerobic incubation was about 1-3 X 10(9)/ml saliva and 1-4 X 10(8)/mg plaque and in aerobic respectively 5-18 X 10(8)/ml saliva and 10(8)/mg plaque. The total CFU on Mac Leod agar was of a similar order of magnitude. The variation between subjects and consecutive determinations was of a similar order of magnitude. The variation between subjects and consecutive determinations was relatively large. The arithmetic mean of the total CFU on Mac Concey agar was about 1-5 X 10(5)/ml saliva, on Rogosa S.L. agar 6-130 X 10(3)/ml saliva and on Sabouraud about 1-2 X 10(3)ml saliva, all in aerobic incubations. Replacement of dietary sucrose with xylitol did not affect the proportion of major microbial categories in saliva or dental plaque. The percentage of typical streptococcal colonies on blood agar was of a similar order of magnitude (about 60-70%) during the diets. The arithmetic and geometric means of the total CFU values on Rogosa and Sabouraud agar plates were significantly lower in the X-group than in the S- or F-groups after a diet period of some months. It was thought that the reason for the reduction of acidogenic and aciduric oral flora in the X-group was partly due to the fact that xylitol is generally not metabolized by these microorganisms.


Influence of steroid hormones on the carcinogenicity of 90Sr. Groups of female CBA-mice were given 90Sr (14.8 kBq/g-0.4muCi/g--bodyweight) alone or in combination with polyestrodiolphosphate, methylprednisolone or nortestosterone, respectively. When 90Sr was given in the first combination, the frequency of osteosarcomas was significantly increased whereas the tumour latency time was decreased compared to mice given 90Sr alone. In combination with nortestosterone such effects were not found, whereas the combination 90Sr + methylprednisolone resulted in a strong reduction of the osteosarcoma incidence and a prolonged tumour latency time. The latter experiment was repeated in a larger experiment whereby the results were confirmed.


Pacemaker wires and electrodes. A follow-up study. In 362 patients on permanent pacing, a follow up with regard to pacemaker electrode function time and connection to pulse-generators has been carried out. In 12 patients Elema epicardial electrode were used with an average function time of 3.8 years. 232 Elema EMT 588 endocardial electrodes were used in 216 patients. Average observation time for the electrodes was 3.3 years. Sixty-eight electrodes have been followed for more than 5 years. Early electrode complications comprise 10 per cent of displacements before implantation of the pulse-generator and another 6 per cent of electrode displacements within the first 3 months after implantation. Eleven per cent of the electrodes had to be corrected due to high threshold value before implantation and another 6 per cent during the first 3 months after implanattion of pulse-generator. On hundred and fifty-five unipolar electrodes of the types Cordis, Medtronic, Elema EMT 282, and Stanium were implanted in 149 patients. Average observation time for the electrodes were 1.2 years. During the first 3 months after pacemaker implant 7 per cent of the electrodes were dislocated, 5 per cent failed due to high threshold value. Three perforations of the right ventricle occurred, without serious complications. Late complications i.e. after 3 months, for EMT 588 electrode included 4 per cent electrode dislocations, 4.5 per cent failure due to high threshold, 3 cases of wire break and 4 defects in the insulation. Many of the late electrode complications were probably caused by replacement operations for pulse-generators. The most frequent late complications for the conventional unipolar electrode was wire break which occurred in 5 cases.


Complications with permanent endocardial electrode systems. The different complications of endocardial electrode systems in 185 patients during the last seven years are discussed. The surgical technique for the now routinely used cephalic route is described. The choice of anaesthesia is discussed. In the last 39 implantations there  have not been any displacements or retractions. Of the total number of patients only 3 required replacement of endocardial by myocardial electrodes. This was caused by unstable position and high stimulation threshold. Fracture of the electrode occurred in 4 cases. Stimulation of the diaphragm occurred in 10%, displacement and retraction of the electrodes in 6,5% and heart penetration or perforation in 3,8% of the patients. There was one death from cardiac tamponade due to electrode perforation of the right ventricle. One case had irreversible brain damage due to prolonged asystole during pulse generator replacement. Unimportant wound infections and haematomas occurred in 5 patients and phlebitis in 3 patients. More or less serious electrode complications have been seen in 56 of the 185 patients, 18 patients having more than one complication.


Displacement of endocardial pacemaker electrodes. A comparison between Elema 588 B and Chardack 5818. The implantation of a permanent pacemaker has been carried out on 159 patients suffering from Adams-Stokes seizures. Elema 588 B electrodes were implanted in 119 patients and Chardack 5818 electrodes in 40 patients. The two types of electrodes differ with regard to both the implantation technique and weight and thickness. No difference was found in the incidence of electrode displacement or survival between the two groups, similarly the experience of the physician with regard to implantation had no influence on the frequency of displacement. Displacement on the other hand occurred significantly more frequently in those patients suffering from heart disease demonstrable by x-ray examination.


Permanent pacemaker treatment at Gentofte hospital. A follow-up study with special reference to transvenous electrode complications, generator longevity and control procedures. Results of a follow-up study of 125 patients treated with permanent pacemakers at Gentofte Hospital during the years 1962--1973 are presented. Complications with endocardial electrodes are reported and longevity curves of pacemaker units are given. The series shows a high frequency of electrode displacement in the first three months and battery exhaustion from the 18th to the 42nd month. The appearance of complications correlates with the frequences of check-up intervals. In order to predict pacing failure due to battery exhaustion, there would seem to be some merit in carrying out an oscilloscopic display of the pulse artifact in addition to the usual measurement of pulse frequency. The aim of this retrospective report is, by analysing a pacemaker series for sudden eletrode failures and battery longevity, to comment on the value of check-up procedures in an outpatient pacemaker clinic.


Complications of transvenous and transtboracic electrodes. Electrode complications in a series of 220 patients are presented. At the primary pacemaker implantation, 114 patients received transvenous and 106 transthoracic electrodes. For the transvenous technique the Elema unipolar electrode (EMT 588 and 588 B) was used exclusively and for the transthoracic technique an epicardial disc electrode (EMT 567) was used in 64 per cent and myocardial electrodes (Vitatron MIP 125, Medtronic 5814 and 6913) in 36 per cent. The material was followed up for an average of three years (from 2 to 10 years). The dislocation frequency of transvenous electrodes was 10.4 per cent/patient-year, as 21 per cent of the electrodes became dislodged. Of the electrode dislocations, forty per cent occurred within the first post-implantation month. Exit block at stimulation with transthoracic electrodes was seen in 8.1 per cent/patient-year. Infections were more common with the transvenous than with the other types of electrodes. The myocardial electrode was significantly (p less than 0.05) more reliable than the transvenous electrode during the follow-up evaluated in terms of uncomplicated function time of the primary electrode. As in Helsinki both endocardial and myocardial-epicardial pacemaker electrodes have been used it seems to be of interest to report the results from our pacemaker material.


Experiences with a new myocardial electrode for permanent cardiac pacing. The first experiences with a new myocardial sutureless screw-in electrode for cardiac pacing are reported. A brief description of the technique is given. The electrode can be inserted quickly and safely under direct vision through a small anterior thoracotomy using a special inserter tool. The heart can be brought under pacemaker control in less than 5 minutes. The technique was employed in 15 patients. Results to date are promising and it is suggested that this method should be resorted to in cases of unstable pacing or recurrent dislocation of an endocardial lead, or when there are difficulties in the proper positioning of an electrode transvenously. In Sweden endocardial electrodes for transvenous insertion predominate. In many countries, especially the U.S.A., there is extensive experience of epi- or myocardial pacing leads (2, 4, 5). Some authors consider epicardial pacemakers safer than endocardial pacemakers for permanent cardiac pacing (8). We have observed defective or unstable pacing with endocardial electrode in a high proportion of patients in our series early after the implantation and even after many years of perfect pacing. When there are problems with an endocardial lead an epi- or myocardial electrode can be used. This paper reports experiences with a new sutureless myocardial electrode (Medtronic model 6917).


Complications from the pacemaker pocket. Prophylaxis, treatment and results. 281 patients who had permanent pacemaker implanted between 1961--73 have been checked at 4 month intervals over a period of 1 to 13 years. Complications from the pacemaker pocket comprises haematoma, skin necrosis, infection of the pocket, allergic reaction to the pulse generator, pacemaker twiddlers syndrome, and muscle contractions. The causes for and treatment of 11 cases with haematoma, skin necrosis or infection are dealt with in detail.


Routine pacemaker control, and selective replacement of pulse generators. A cost/benefit analysis. Two hundred and fifty patients with permanent pacemaker have been followed up with routine pacemaker controls in a pacemaker clinic for a 21 months period 1/3-73 to 1/1-75. Ninety-five pulsegenerators were replaced. Sixty-two of the replacements were due to impending battery exhaustion, nine elective and 24 for other reasons. Signs discovered by the patients led to replacements in 21 cases for impending battery exhaustion and in 17 cases for other reasons. Forty-one replacements for impending battery exhaustion and 7 other replacements followed a scheduled visit to the pacemaker clinic. The selective replacement policy resulted in an average gain of pulsegenerator lifetime of 6.5 months, compared to a 24 minths elective replacement policy. Increased safety is obtained by routine control of pacemaker patients in a pacemaker clinic.


The value of an oscilloscope in routine checking of pacemakers. An evaluation has been made of the usefulness of the oscilloscope at routine check-ups of cardiac pacemakers. Measurements of 100 consecutive implanted pacemakers, obtained after their removal have been compared with changes in rate and changes in impulse duration and amplitude obtained at previous routine controls. Other changes in pacemaker characteristics have also been evaluated. Eight faulty pacemakers were found. Six had a decreased voltage, none however, less than 3.5 volts. Five of them had shown a decrease in rate by at least 7 impulses per minute, while in one QRS-synchronized pacemaker the synchronizing circuit did not function. In one pacemaker the stimulating rate had increased with 20 impulses while in one P-synchronized pacemaker the delay time had decreased. In 6 patients a significant decrease of the impulse amplitude was noticed without fall in voltage or electronic failure and in 3 others no decrease of the impulse duration was noticed in spite of decreased voltage at check after explantation. The present study therefore indicates that, at routine check-ups of the presently analyzed pacemakers with voltage depending stimulation rate, an analysis of the latter gives satisfactory information of pacemaker function and can be used instead of oscilloscope test, eventually in combination with electronic measurements of impulse duration.


Permanent endocardial pacing. An analysis of 90 patients. Primary results and follow-up observations in 90 patients with permanent endocardial pacing--covering the period from 1970 to June 1974--are reported. The primary mortality was 3% (3/90), and mortality 4% (4/90). Electrode complications were the most common problem and occurred in 20% implantations. Early or late dislocation of the electrode tip was seen in 12%. With the improved technique is was possible to decrease it significantly through the period. The mean battery life time of Siemens-Elema pacemakers was 26 months. 10% of the failed batteries were replaced urgently. So far the rather high frequency of electrode complications diminishes the advantages of the pacemaker treatment.


ECG telemetry for pacemaker check-up.

ECG telemetry for pacemaker check-up. Experience from 1 000 ECG transmissions by telephone for check-up of pacemaker patients is reported. The method and its indications are described. The quality of the ECG is usually good, but sometimes there are unsuccessful transmissions, and the technical problems are discussed. An adequate analysis of cardiac pacing function could always be made. Furthermore, valuable information of different types of arrhythmia was gained on several occasions.