Remission maintenance of acute nonlymphoblastic leukemia with BCNU (NSC-409962) and cyclophosphamide (NSC-26271). Thirteen of 29 patients with acute nonlymphoblastic leukemia achieved complete remission with cyclophosphamide, cytosine arabinoside, and vincristine, and remissions were maintained with a combination of BCNU and cyclophosphamide. The maintenance drugs (200 and 1000 mg/m respectively) were given at 8-week intervals intravenously. Only six of the 13 patients achieving a complete remission have relapsed. The projected median duration of complete remission is 65 weeks and of survival from diagnosis is 144 weeks. These remission and survival durations compare favorably with the results achieved using other forms of remission-maintenance therapy. The advantage of our form of maintenance therapy is that only overnight hospitalization is required at 8-week intervals.


Experimental studies of the antitumor activity of amygdalin MF (NSC-15780) alone and in combination with beta-glucosidase (NSC-128056). Amygdalin MF was evaluated alone and in combination with an activating agent, beta-glucosidase, against three transplantable rodent tumors; Ridgway osteogenic sarcoma, Lewis lung carcinoma, and P388 leukemia. In dose-response studies up to the LD20 in normal mice, amygdalin MF alone did not demonstrate significant antitumor activity against any of these three tumor systems. Similarly, at doses not exceeding the LD10 in normal mice, amygdalin MF plus beta-glucosidase did not demonstrate antitumour activity against any of these three tumor systems. Potentiation of the lethal toxicity of amygdalin MF by beta-glucosidase was observed in all studies where the two agents were given in simultaneous combination.


A comparative study of results of the von Langenbeck and the V-Y pushback palatoplasties. The incidence of velopharyngeal competence noted in 267 cleft palate patients following palatoplsty has been reviewed. Comparisons have been drawn with regard to the cleft type and the surgical technique performed. Since there were relatively small numbers of subjects in some categories, differences in age at last examination between the von Langenbeck and V-Y palatoplasty groups, some patients were very young at time of evaluation, and a number of different surgeons at different levels of training and experience performed the surgery, the differences in velopharyngeal competence found should be viewed as trends and this report as preliminary. In general, there was a trend toward smaller percentages of patients attaining acceptable velopharyngeal competence as the severity of the cleft increased. Of those with clefts of the soft palate only 86 per cent achieved competence. Among those patients with clefts of the palate only, 67 per cent achieved competence, whereas only 57 per cent of those with clefts of the lip and palate were able to do so. When comparing all cleft types, the V-Y palatoplasty resulted in a significantly higher percentage of velopharyngeal competence (74 per cent) than did the von Langenbeck method (56 per cent), although the data for the V-Y group are probably less reliable than those for the von Langenbeck group. In the soft palate only category, the results were slightly better with the von Langenbeck technique, though not significantly so. In all other cleft types, the results with the V-Y method were better than those with the von Langenbeck.


"Nasalance" vs. listner judgements of nasality. In this article, judgements of nasality from sound field recorded utterances of 23 children with repaired palatal clefts are compared with "nasalance" values derived from TONAR II analyses of parallel sound separated recordings. For the nasality judgements, the sound field recordings were presented in forward reproduced mode to 20 "naive" listeners and in backward reproduced mode to 10 naive listeners. A four-level task progression was followed in each mode of presentation: sorting the responses by "normal" or "abnormal" nasality, ranking them by severity of nasality, classifying them within five degrees of nasality, and, finally, assigning a discrete score to the magnitude of nasality perceived in each recording. Scores from the individual judges were highly variable, especially in the first listening task. They were consitently more variable when nasality was judged from backward reproduced recordings. As the listeners gained experience and as the listening tasks demanded more precision in nasality judgements, variability was reduced. Correlations computed between the nasality ratings and nasalance measurements increased and variability decreased. Highest agreement between physical and perceptual measurements was found when variability among the judges was reduced by pooling the scores and comparing the mean scores of nasality with the nasalance scores. Using this procedure, a correlation of .91 was obtained between listener judgemental scores of forward reproduced speech and nasalance scores. Under these conditions, the instrumental score could apparently account for over 80 per cent of the variability in the listener judgements of nasality. From the findings of this study, it was concluded that listeners without prior training are capable of judging nasality reliably and that nasalance scores provide a valid correlate of perceived nasality. The use of backward reprodeced recordings was questioned as a means of assessing nasality.


Behavior and achievement of cleft palate children. Forty-four cleft lip and palate/palate only children were individually matched with forty-four normal school children on the basis of sex, age, grade, intelligence and socioeconomic status. All children received behavioral ratings by classroom teachers, and achievement test scores were obtained. The cleft children were rated by teachers as displaying significantly greater inhibition of impulse (internalizing behavior). Cleft children also were significantly lower on overall basic skills achievement test scores. It was suggested that cleft children may be responding to the social-behavioral environment which may include negative social responses from others.


Repeated superiorly based pharyngeal flap operation for persistent velopharyngeal incompetence. A secondary pharyngeal flap procedure, superimposed, on the primary flap, is described after having successfully improved the speech of the three patients on whom it has been used. The raising of a secondary flap is made possible by the fact that minimal scarring occurs from previous pharyngeal flap surgery and also because of the presence of a muscle layer. The combination of factors leading to further reduction in the size of the velopharyngeal lumen is discussed. This operation offers some measure of hope for the not insignificant number of patients who have been left with poor speech after pharyngeal flap surgery and supports the recent work of Cosman and Falk (2).


Survey of publications for parents of cleft palate children: a preliminary report. In summary, these findings indicate that the general quality of the publications for parents of cleft palate children is probably mediocre and that both parents and speech pathologists tend to agree on assessments to this effect. The publications which appear to be most widely used are not necessarily those which appear to be the best available. Attention needs to be given to the design and content of future parent publications which should probably be written with knowledge of the parents' changing concerns over time. Since parent publications are used by many professionals involved in clef palate habilitation and there is no information about their opinions of the quality of these publications, additional work on this problem is planned for the future.


Spheno-pharyngeal meningocele and cleft palate. Case report with 12-year follow-up. A rare congenital anomaly consisting of a spheno-pharyngeal meningocele and cleft palate is presented. The repair of the meningocele was accomplished through an intra-oral transpalatal approach. A primary pharyngeal flap was used to accomplish the repair of the cleft palate. Fortunately, there were no important anomalies of the central nervous system. Twelve years later, the patient functions normally and speaks well. The only remaining symptom of midline craniofacial dysmorphia is a mild hypertelorism.


[Comparative studies on the cleansing action of short head toothbrushes with various bristle fields]. With 20 probands (dental students) comparative clinical-experimental studies on the cleaning effect of short headed toothbrushes with different arrangement of the bristles were performed. The following was found: 1. Position and form of the bristle bundles of short headed toothbrushes--as far as they are at all useful--do not appear to have any influence on the efficiency of the cleaning of teeth in a periodontally healthy dentition without any special positional anomalies of the teeth. 2. Cleaning the oral dental surfaces involves considerable difficulties and usually is successful only after repeated instructing. 3. Mesial and distal dental surfaces are cleaned to about the same extent. 4. Even with skilled persons (instructed dental students) optimum cleaning of the teeth is achieved only after about 4 minutes of intensive cleaning.


[Clinical results with Edlan and Mejchar's vestibuloplasty]. In 9 patients, the mode of postoperative healing and the obtained vestibular depth were examined after operations according to the Edlan and Mejchar method. Despite minor subjective complaints, quick healing was observed. Eighteen months later, the vestibulum still had the originally obtained dimensions.


[Diagnostic-therapeutic aids in the reconstruction of frontal occlusion]. Two methods are recommended as diagnostic-therapeutic means for controlling frontal interlocking: 1. Composite materials for temporary onlays on canines, 2. incorporation of a miniplast splint with individually shaped occlusal surfaces made of cold curing acrylics in cases of isolated interferences in protrusion as well as interferences in both protrusion and lateral movement of the front teeth.


[Thermoanalytical studies on gypsum- and phosphate-bonded casting investments]. The two test series were carried out with the dilatometer TMA 500 (of Haereus company). The measurements for thermic expansion are easily reproducible, not so for setting expansion. The recorded setting expansion values are identical with the manufacturers' data given for Luster Cast, Aurovest, and Deguvest HFG, among the thermic expansion values only those for Luster Cast are in line with the data given; the values given for Bayer DC are most different from those we found.


[The chemical analysis of dental mercury]. Various samples of two commercial dental mercuries were tested by chemical analyses with regard to metallic impurities (Fe, Cu, Ni, Zn, Mn, Cd, As, Tl, AG, Au). The surfaces of some of the tested samples were no longer bright and clear. The detectable metallic impurities reached a maximum of about 2 ppm.


[Correlations between the microstructure and the "creep" of amalgams]. For several preparations the creep behavior of amalgam which is gaining increasing clincal importance is put into relation to tested micro-structure, composition of the initial filings as well as the newly developing phase and its components. Interrelationships between the initial alloy and the gamma1-phase on the one side and the respective creep on the other were observed.


[Experiences with acupuncture in the treatment of trigeminal neuralgias]. In the present paper it is reported on therapeutical experience gained within one and a half years at 27 patients with various forms of trigeminal neuralgias. In the group of the idiopathic, symptomatic, and atypical forms, therapy was totally successful in 55%, relatively successful in 35%, and failed in 10% of the cases. As to the psychogenic form, therapy was successful in 6 of 7 patients. Within a year after therapy had been terminated, a third of the patients suffered a relapse. When repeating acupuncture, patients do not seem to respond to the therapy as favorably as before.


[Dosage and cariostatic effect of mutanase in a rat experiment]. In caries tests on rats, mutanase (mu-1,3-glucanglucano-hydrolase) was admixed in different quantities to a cariogenic diet. The animals were fed eight times a day with a feeding machine for 25 days. A highly significant inhibition of fissural caries was achieved by concentrations of over 50 MU per gram of diet. As a simultaneous plaque reduction was not observed, the effect of the enzyme appears to be due to reduced adhesion or colonization capacity of streptococcus mutans strains in the fissures.


[Scanning electronmicroscopic studies on fissure caries in human teeth]. Fracture surfaces and ground sections of human molars with fissure caries were examined under the SEM. The pictures confirmed that with the SEM the topographical location of the fissure as well as the main stages of carious decay in the enamel and dentine (demineralization, infiltration by cariogenic substances and microorganisms) could easily be seen three-dimensionally. Primarily the question of demineralization of prism core and prism periphery was discussed by means of own findings and findings made by other authors.


[Lockjaw in progressive myositis ossificans]. Frequency, symptomatology, course and therapy of myositis ossificans progressiva are described by means of literature references and personal observation in a patient. The patient was born in 1935 and the disease manifested itself for the first time in 1956 in the right sternocleidomastoid muscle. Despite surgery total trismus could not be prevented and later-on muscles and connective tissue of other areas ossified, too.


[Toxicity tests in vasoconstrictor agents added to local anesthetics]. The toxicities of adrenalin, nor-adrenalin and vasopressin derivatives were compared on the basis of animal tests, among others. The adrenalin additive is rejected.


[The occurrence of Streptococcus mutans variants in man and laboratory animals]. Numerous S. mutans strains isolated from human dental plaque and from that of rats and hamsters were classified by a well-known biochemical differentiation system for the separation of the serotypes "a to e", and by seven different biotypes (I-VII). 182 S. mutans strains from human plaque were assigned to the following serotypes: "c" = 68%, "d" = 19%, and "b" and "e" = 4% each. Serotype "a" was not found at all and 10 strains could not be classified. Out of 60 S. mutans strains from the oral cavity of rats, 85% belonged to serotype "c", while in 25 strains from hamsters serotypes "e" and "d" predominated.


[The cariogenicity of xylitol-decomposing bacteria in a gnotobiotic study]. In gnotobiotic tests in rats, two xylite-degrading streptococcal strains were tested with regard to their cariogenic properties. One strain was isolated from human dental plaque, the other from the oral cavity of rats. The test animals were associated with the test strains only, and received a saccharose, fructose or xylite chocolate diet for 12 weeks. At the end of the test, between 10(4) and 10(5) inoculated germs were found in the plaque of the test animals. The total caries incidence in the gnotobiotic rats was insignificant in all test groups, i.e. whether they were given saccharose, fructose or xylite chocolate diet, and in both test strains. As compared to the cariogenicity of an S. mutans reference strain, the cariogenic effect of the tested strains was without any practical importance.


[Comparative studies of dental plawue in students with and without dental caries. I. Enzymatic determination of the capacity to synthesize lactic acid in an aerobic medium]. In cultures of dental plaque taken from healthy dental surfaces of children susceptible to caries and children free from caries, the lactic acid content was determined. The cultures had an initial germ count of between 10(3) and 10(4) organisms per ml. After the cultures had been kept in artifical saliva for 7 hours under aerobic conditions, the samples of caries-susceptible children showed a considerably higher acid content than those of caries-free children. In comparative tests carried out in plaque samples simultaneously taken from the same dentitions, the micro-organisms of the samples taken from carious dental surfaces produced more lactic acid under the above mentioned conditions than those of the plaque samples taken from healthy dental surfaces.


[The variation of the depth of the cervices in the ground surface of the tooth]. Variations in the depth of scratches in a transverse section of a premolar was studied. The scratches were produced by a Vickers diamond whose vertical deviations during scratching were measured by an inductive distance recorder and continually registered by an xy-recorder. The depth of scratches in all areas of the enamel was almost constant with only minimal variation. In the dentine, too, the variations were small, the constant being greater than in the enamel. The greatest depth was measured in interglobular dentine.


[Ultrastructure of conditioned enamel surfaces and their adhesive matrices in dental enamel sealing]. The enamel sealant Nuva Seal was tested in model tests on caries-free human molars and premolars. Under the scanning electron microscope the acid-etched enamel areas (natural and ground surfaces) and the corresponding Nuva Seal matrices were studied. In the evaluation, the surface reliefs of the objects were compared. Thus, information on flow capacity, wetting and polymerization behavior of the adhesive was obtained. Evaluation of pairs of stereo pictures of the inverse surface reliefs in the enamel/adhesive contact zone suggests that the sealant has an average measurable depth of penetration of 7 mum. Peg-shaped elevations 10-20 mum in size that can sometimes be observed in the Nuva Seal impressions are interpreted as representing enamel defects.


[Clinical results of functional bite analysis. III. The effect of objectifiable factors upon the therapeutic results]. The influence exerted by objectifiable factors on the therapeutic result of temporo-mandibular joint disorders was analyzed in follow-ups carried out in 73 patients. As the most frequent cause of still existing complaints occlusal interferences, especially balance contact, were found. The majority of these balance contacts had developed after termination of our therapy, as a result of occlusal surfaces having an unfavorable shape with regard to masticatory function or as a result of spaces in the dentition that had not been treated prosthetically. It was possible to demonstrate that lasting therapeutic success is mainly due to the consistent securing of an interference-free centric and eccentric occlusion. Function controls should also be carried out as a routine measure in people with healthy temporo-mandibular joints, in order to guarantee improved prophylaxis of disorders in the stomatognathic system.


Applied behavior analysis in the treatment of childhood feeding problems. This paper discusses behavioral mismanagement as a cause of feeding problems in children and reports the case of a six-year-old handicapped boy who was subsisting almost entirely on pureed foods at the time of his referral. Treatment with applied behavior analysis resulted in his acceptance of food normal for his age, and at follow-up 12 months after treatment the variety of foods eaten and the nutrient intake were virtually normal for his age. The authors discuss the frequent occurrence of feeding problems in children and their possible causes. They propose that such problems constitute a clinical entity and suggest a preliminary classification system for them.


Serological surveillance of children with CSF shunting devices. A naturally-occurring, age-related rise in titre of antibody to Staph. albus in both hydrocephalic and non-hydrocephalic children is demonstrated in this report. In view of this finding, the value of serial determinations of antibody titre in children with shunts is discussed in terms of an organised surveillance programme.


Reconstitution of the cerebral cortical mantle in shunt-corrected hydrocephalus. The purpose of this study was to ascertain the sequence of events and the cellular constituents involved in reconstituting the cortical mantle after ventricular shunting. The subjects were severely hydrocephalic adult cats. After insertion of a shunt, the ventricular system rapidly returned to normal size and there was gross reconstitution of the cortical mantle. However, there still remained in the cortical mantle many of the histological changes seen before insertion of the shunt. The effect of hydrocephalus is mainly upon axons in the periventricular white matter. The axons become stretched and finally disrupted, resulting in disintegration of the surrounding myelin. In the absence of axons, remyelination cannot take place. It would seem, therefore, that prompt reversal of hydrocephalus is necessary in order to preserve the anatomical and functional integrity of the brain.


The tectum and the aqueduct of Sylvius in hydrocephalus unassociated with myelomeningocele. The brains of 30 children with hydrocephalus (but not myelomeningocele) were examined. It was found that secondary pressures on the tectum and aqueduct resulting from the hydrocephalus were responsible for further obstruction at this level in 15 of the 30 children and that they contributed to axial distortion in another 11 children. Occlusion of the aqueduct occurred as a result either of these external pressures or of internal gliosis. These events form a self-sustaining cycle which, if broken early, may lead to a more satisfactory control of the hydrocephalus.


Dandy-Walker syndrome associated with congenital heart defects: report of three cases. Three cases of Dandy-Walker syndrome associated with congenital heart defects are reported, and their management is described. The various theories concerning the aetiology of the Dandy-Walker syndrome are discussed and it is suggested that the theory of primary developmental atresia of the foramina of Magendie and Luschka is still acceptable. If the child with Dandy-Walker syndrome requires treatment by extracranial CSF drainage it is proposed that a ventriculo-peritoneal shunt is preferable when there is any suspicion of cardiac anomaly. The proximal catheter should be placed in the posterior fossa cyst (dilated fourth ventricle) rather than in the lateral ventricle.


Changes in regional blood-flow and water content of brain and spinal cord in acute and chronic experimental hydrocephalus. The effects of kaolin-induced hydrocephalus on regional blood-flow and water content of cat brain and spinal cord were measured. The role of the central canal of the spinal cord as an alternative pathway for cerebrospinal fluid in experimental hydrocephalus was also studied by positive contrast ventriculography. In comparison with normal cats, blood-flow in the cerebrum, cerebellum and brain stem of cats with acute hydrocephalus was reduced by more than 20 per cent: in those with chronic hydrocephalus it was reduced by only 12 per cent. There was an absolute increase of 1-5 per cent in water content of the brain in cats with acute hydrocephalus. Water content in the spinal cord was increased by 6 per cent in cats with acute hydrocephalus and by 8 per cent in those with chronic hydrocephalus. When the increased water-content was taken into account, hydrocephalus caused no significant change in blood-flow in the cervical, thoracic or lumbar spinal cord. Contrast material perfused through the ventricles of hydrocephalic cats flowed directly into the enlarged central canal of the spinal cord. Kaolin-induced arachnoiditis completely obstructed communication between the ventricles and the cranial subarachnoid space. The contrast material in the central canal communicated both with the cavities extending into the dorsal columns and with the spinal subarachnoid space. When kaolin was injected directly into the spinal subarachnoid space there was an increase in spinal water-content, without an enlarged central canal. These results suggest that in addition to kaolin-induced arachnoiditis, increased intraluminal pressure is necessary to enlarge the central canal.


Cerebrospinal fluid dynamics in megalencephaly. Macrocephaly is one of the signs most commonly used in the diagnosis of hydrocephalus. Two children are reported who presented with macrocephaly. The results of neurological examination were normal apart from delay in mental development. Head circumferences were above the 98th percentile. Air studies showed mildly dilated ventricles with no obstruction, and ventriculolumbar perfusions indicated normal rates of cerebrospinal fluid formation and absorption. At seven years of age the children were mildly mentally retarded, with head circumferences above the 98th percentile. In the girl the ventricles were still mildly dilated but in the boy they were normal. It is concluded that the macrocephaly in these two children was the result of progressive megalencephaly and not of abnormal ventricular enlargement (hydrocephalus).


The problems of design and implantation of shunt systems for the treatment of hydrocephalus. Engineers and surgeons concerned with the design and use of shunt systems for the treatment of hydrocephalus share the wish to avoid the implantation of defective devices and to improve existing shunt systems. This study considers the causes of shunt failure or malfunction and seeks to define the areas in which improvements are needed. An important factor in bringing about improvements is that surgeons communicate to designers and manufacturers their clinical observations of defective materials or performance in existing shunt systems.


A study of the Indian valve for ventriculo-atrial shunts in the treatment of hydrocephalus. Because of the high costs of importing commercially-available shunts, a hand-made ventriculo-atrial shunt was devised in India for the treatment of hydrocephalus. Modifications have been made to the original design and these shunts are now being produced commercially at a fraction of the cost of other available shunts. Hydrodynamic testing indicates that they compare favourably with the other shunts at present in use.


The use of the valvogram for the detection of shunt blockage in hydrocephalic children. Valvography is a simple, safe, rapid, easily interpreted technique for the investigation of possible blockage of the distal end of the shunt system containing a Spitz-Holter valve. Details are presented of 64 investigations in 46 children, 30 of which demonstrated distal obstruction of the shunt system. The unreliability of some physical signs is discussed. No serious complications were encountered and the procedure has proved to be a valuable addition to the practical management of shunt-dependent children.


Antibiotic prophylaxis in shunt surgery. A system of antibiotic prophylaxis has recently been described which is said to lower the incidence of wound infection in various surgical procedures, and which also evades the problem of increase in resistant bacteria. In the investigation reported here, this system was applied to the prevention of colonisation following shunt surgery and was found to have no beneficial effect. It is suggested that this finding may be peculiar to operations involving the implantation of hollow devices.


Immunological aspects of L-asparaginase treatment in children with lymphoproliferative disease. 14 children with acute lymphoblastic leukemia and 6 with lymphosarcoma were treated in 13 cures with 300-500 IU/kg bodyweight/day of L-asparaginase and in 11 cures with 501-760 IU/kg/day. An increase of all fractions of immunoglobulins with maximal values at the end of the cures was observed in the group treated with low doses. In the children receiving the high doses of this drug, an increase was observed only in the first 3 or 4 days of therapy and a decrease occurred at the end of the cure. Decreased IgM levels at the end of therapy were noted in children with acute leukemia. Anti-asparaginase antibodies occurred only in 3 children with anaphylactic shock.


Population cytology of the genus Phaulacridium. IV. Phaulacridium marginale (Walker)--the North Island populations. Samples of Phaulacridium marginale were taken from the North Island of New Zealand, together with further samples from three South Island populations. Seven of the North Island populations were found to be polymorphic for a small telocentric B chromosome. In only one case was the B chromosome significantly associated with an increase chiasma frequency. All three South Island populations contained B chromosomes. Seven of the nine N.I. populations were also polymorphic for extra segments on the centric end of the S11 chromosome. In six of them this polymorphism co-existed with that for B'S. A new polymorphism was encountered in two populations. This was for a large block of heterochromatic material located at the centric end of one of the smaller medium-sized chromosomes which thus becomes acro- rather than telocentric. Tt would appear that the New Zealand grasshopper, Ph. marginale, is able to tolerate many different polymorphisms for extra heterochromatin. However, this ability is perhaps restricted to central populations. In this context, the high level of occurence of these polymorphisms in the North Island could be due to the better climatological conditions existing there compared to most of the South Island.


Gene frequences in Icelandic cats.

Gene frequences in Icelandic cats. A survey of genetically determined coat polymorphisms of Icelandic cats, in Reykjavik and adjacent rural areas, has shown that these animals are quite distinct from cats previously studied in north-west Europe. The differences are interpreted to indicate that Icelandic cats represent a relict population reflecting the condition of north-west European cats in former times. Significant differences exist between the Reykjavik and rural samples studies. The Reykjavik population is more similar to north-west Europe, probably due largely to increased contact in recent years.


Selection equilibria in a multiallele single-locus setting. The aim of the paper is to clarify and unify various well-known results in the setting mentioned in the title, since some of these results are either inaccurate, or incomplete; or refer to different concepts bearing the same name. Emphasis is given to the general case, i.e. we include the situation of singular fitness matrix, a topic which is generally avoided. We proceed by using a specific generalized inverse of the fitness matrix. A full bibliography is given.


The effects of selection and human preference on coat colour gene frequencies in urban cats. In an attempt to examine the possibility of selection on domestic cats populations in the urban environment, a number of surveys were conducted in four contrasting areas of Glasgow--two near either extreme of Western, industrial socioeconomic status. The first survey was in the form of a questionnaire to inhabitants enquiring of preference for a particular phenotype. This survey revealed a consistent preference for lighter phenotypes in all areas. The incidence of cat ownership was greatest in the two affluent areas where there was also a high risk of the cat being sterilised. Independent of the questionnaire survey was a study of cat coat colour gene frequencies in each of the four districts. This study revealed that darker phenotypes predominate in the two areas of lower socioeconomic status, Maryhill and Govan. To date, the cat populations in these two areas are the darkest to have been described in the world. In contrast, a lighter phenotype was found in cats inhabiting the two districts of higher socioeconomic status, Kelvinside and Bellahouston. This difference in phenotypic darkness was also paralleled by appropriate clines in coat colour gene frequencies. The results demonstrate that human preference is not effectively translated into selection at any of the loci considered. In situations where human preference is most likely to occur, neutering risk is also high. Although the force responsible for the darkening of phenotype has yet to be identified, the fact that the darker alternative allele at each of the O, a, t, d, S and W loci is favoured suggests that selection is operating on these polymorphic coat colour loci.


Chiasma frequency variation with altitude in Cepaea hortensis (můll.). Populations of Cepaea hortensis have been sampled from an area of 121 sq km on the north slopes of the Brendon Hills, Somerset, and analysed for chiasma frequency. Variation in chiasma frequency is due to variation in a single large bivalent--the A group bivalent. In 12 populations studied during 1973 no association between chiasma frequency and ecological factors could be detected. In particular, there is no evidence of a negative correlation of population density with chiasma frequency which is known to exist in populations of C. nemoralis within the area. In 1974, 17 populations, four of which were utilised in the 1973 analysis, were studied. Negative correlations of interstitial (but not total or terminal) chiasma frequency and between-cell variance with altitude were found. It is likely that the correlation of between-cell variance with altitude is due to the strong correlation of variance with chiasma frequency which exists in these populations. There is evidence from several populations that chiasma frequency is stable between years. The implications of the negative correlation of chiasma frequency with altitude and the lack of a correlation with population density are discussed.


Population genetics of a "colonising" lizard: natural selection for allozyme morphs in Anolis grahami. Allozyme frequencies of Anolis grahami from Bermuda were compared to those from Jamaica. These lizards were introduced into Bermuda from Jamaica in 1905. The magnitude of the genetic changes were consistent with the hypothesis that these changes were produced by random genetic drift. The changes for the seperate alleles were, however, more heterogeneous than expected if caused by random drift alone. It is concluded that not all the alleles examined have been selectively neutral.


High coumarin 7-hydroxylase activity does not protect mice against Warfarin. Sixteen strains of mice varied widely in their ability to 7-hydroxylate injected coumarin to form umbelliferone, which is excreted in the urine. The same strains also varied in their resistance to the lethal effects of dietary Warfarin. There was no correlation between hydroxylating ability and Warfarin resistance.


Phenotypic selection in autopolyploids.

Phenotypic selection in autopolyploids. A simple demonstration, applicable to any ploidy level, that response to selection measured after one generation of random mating is proportional to the gametic variance, is given. The reduction in the coefficients of variance components during subsequent random mating generations is related to the approach of the population structure to various types of equilibria.


[Role of salivary lipids in the precipitation of a salivary glycoprotein under the effect of calcium]. During its purification, a calcium precipitable glycoprotein, isolated from human mixed saliva was submitted to dialysis. When purified, this glycoprotein did not precipitate with the addition of calcium. The study of the precipitation conditions showed that during dialysis salivary lipids passed in the dialysate. Dialysated saliva gave no precipitate by calcium addition. Precipitation experiments of dialysated saliva and reprecipitation of the purified glycoprotein by calcium, in presence or absence of salivary lipids, showed that these latter were indispensable for the precipitation of the calcium precipitable salivary protein. These results demonstrated a possible role played by salivary lipids in the elaboration of dental plaque, whose matrix contained relatively important lipid quantities.


[Vascularization and connective tissue penetration, factors in the involution of the enamel organ in the rat]. In the albino rat, at the 21th day of gestation, the capillaries entered the stellate reticulum of the molar and came into contact with the stratum intermedium. This vascular penetration was followed on the 10th day of age by a connective penetration. The stellate reticulum was thus disorganized and was built up by small epithelial islands surrounded by collagen and reticulin fibrils. Finally, the reduced enamel epithelium fused with the oral epithelium and formed the epithelial attachment. After a trophic role, the vascularization, with the help of the connective tissue penetration, had a destructive function. Both vascularization and connective tissue invasion contribute to the enamel organ involution.


Blood supply in the developing and post natal rat soft palate. Foetal and post natal rats were perfused with a carbon suspension and cleared in methyl salicylate to display the blood supply of the developing and formed hard and soft palates. The arterial blood supply of the soft palate was from the pharyngeal artery, a branch of the pterygopalatine artery; and from the tonsillar artery, a branch of the external maxillary artery. The pharyngeal artery could be recognised from 14 days post insemination and reached its adult configuration on the 17th day p.i. The tonsillar artery was seen from the 18th day. In the hard palate the blood supply was as described by other authors.


[Architectural structure of the pterygoidian plane of the masticatory musculature in the cat (Felis catus L.)]. The architectural analysis of the ptérygoidal plane of the cat identified the two pterygoid muscles. The medial pterygoid showed an orbital and an angular part inserted respectively on the internal face of the mandibule and on the maeto-angular ligament. The lateral pterygoid consisted of only one pterygoid bundle, involved in lateral movements and adjustments of the jaw condyle.


[Influence of various anions and biological macromolecules on bacterial aggregation in vitro]. The effects of various anions on experimental bacterial aggregation has been studied with Streptococcus mutans OMZ 175 and Actinomyces viscosus X1, using an experimental system, based on the measurement of optical density in an aqueous polyethyleneglycol medium. Monovolent anions (acétate, chloride and fluoride) and sulphate had no effects on bacterial aggregation in salivary concentrations. However carbonate, mono and dihydrogenophosphates gave an important aggregation in relatively small saline concentrations. The study of the aggregation of Strep. mutans OMZ 175, grown in presence of sucrose for 12 to 96 hours, showed an increased aggregation of the micro-organims up to 24 hours. For longer incubation times, aggregation decreased. Finally a calcium precipitable salivary glycoprotein, at small concentrations, gave a bacterial aggregation of about 25% and may be important in dental plaque formation.


[Application of a segmentation method to an intraoral epidemiologic survey]. The segmentation method has been applied to the results of an epidemiological study on the oral conditions of 2000 children of Strasbourg, 6 to 15 years old. The classification in decreasing order of the factors influencing the DMF/T index was the following: the age, the socio-professional group of the father, the sex, the calculus index, the gingival index, the df/t, the morphological index and the plaque index. The df/t index was bound in decreasing order of importance to the DMF/T index, the age, the socio-professional group of the father, the sex, the calculus index, the gingival index, the plaque index and the morphological index. For the gingival index, the segmentation analysis indicated in decreasing order the importance of the plaque index, the socio-professional group of the father, the age, the DMF/T index, the calculus index, the df/t index, the morphological index and the sex.


[Lipids of the human gingiva].

[Lipids of the human gingiva]. Human normal gingiva showed a distribution of 2/3 of non phosphorylated lipids and 1/3 of phospholipids, as well as a prevalence of free fatty acids, triglycerides and esters of cholesterol in relatively high rate. An important quantity of phosphatidylcholines, of phosphatidylethanolamines and sphingomyelins was also noted. The other phospholipids were present but in smaller quantity. The participation of the phsopholipids in the keratinization process of the oral mucosa has been discussed.


[Role of hypocalcemia in the keratinization of the epithelium in the rat]. The role of calcium in the keratinization process has been studied in hypocalcaemic rats after surgical removal of the parathyroids. Intraperitoneal injection of Na2(35) SO4 allowed the study of the incorporation of sulphur in palatal and gingival epithelium. After parathyroidectomy, the calcaemia decreased strongly in the first week, reached its lowest value at the end of the second week and then increased progressively. In the control rats, the concentration of the silver grains increased from the basal layer to the stratum corneum, whereas in the parathyroidectomized rats the grains were concentrated in the basal layers. The variations of the values of the calcaemia and the number of grains were in correlation for the palatal and gingival epithelium. This correlation seemed to be confirmed for the palatal epithelium by the results obtained by radioactivity measurements. A relation between the calcium plasmatic concentration and the sulphur incorporation seemed to be confirmed. The hypocalcaemia was accompanied by diffusion anomalies of sulphur and glycoaminoglycans sulphation.


Normal histology of the human soft palate. The histology of the human soft palate seen in four whole soft palates and four mucosal biopsies has been described, with an emphasis on the elastic fibres. Striking features were the presence of much fat, thick interglandular connective tissue septa, considerable elastic tissue, and a complete absence of taste buds.


[Quantitative study on the effects of occlusal overload on the remodelling of the alveolar process in the rat]. A quantitative study of alveolar bone resorption around the first lower rat molar has been conducted on horizontal sections. The number of osteoclasts/mm2 and the percentage of resorbing periodontal membrane surface of the socket rose through an increase in occlusal forces induced by an amalgam filling in slight occlusal overbite. The increase in resorption was significantly related to the duration of force application. The number of osteoclasts was more than tripled after 18 days. But this increase was observed in areas already previously submitted to osteoclastic resorption during bone remodeling associated with physiological tooth drift.


[Action of calcitonin in experimental periodontolysis in the golden hamster]. 48 male goldern hamsters 5 weeks old were divided in 4 groups. The first group was used as control. The second was submitted to the 2 000 cariogenic Keyes diet inducing severe alveolar bone resorption. The third and fourth group received with the same diet a thyrocalcitonin injection every two days (3rd group) and every day (4th group) during three months. The study of the alveolar plates with the scanning electron microscope in the animal having received thyrocalcitonin showed a reduced number of resorption lacunae, a denser bone surface covered by a homogeneous and dense granular material similar to that observed in the controls. The calcified globules, constituting the bone anchoring of the Sharpey's fibres, were different from those of the second group submitted to Keyes diet and similar to the controls.


[Morphogenesis and structure of teleost teeth (Salmo fario L.)]. Tooth formation has been studied in the fry and adult trout (Salmo fario L.) in order to describe their structure and investigate the links between histogenetic and architectural features. Odontoblasts show typical polarized kinetics during their activity; they shrink back from the tooth wall they have elaborated, without leaving any cytoplasmic process (Tomes' fibres); so the dentine in a characteristic way lacks any cellular or canalicular inclusion, at any stage of its development. The tooth as a whole grows from an apical to basal direction; its organic matrix is formed of coarse fibres from the pulp, and fine collagenous fibres formed by the odontoblastic layer. These various fibrillar systems assume definite orientations. Mineralization was studied by fluorescent markers and microradiography. The external apical part of the tooth is hypermineralized, but its structure and pattern of deposition would make it closer to a dentinal differentiation (enameloid) than to an ectodermal enamel. The ameloblasts of the inner epithelium are high, very polarized and active cells, but their participation in tooth tissue formation has not been definitely demonstrated.


[The peri-angular masseteropterygoid belt in the cat (Felis catus L.)]. The fleshy bundles of the first lamina of the cat (Felis catus L.) superficial masseter were highly developed, wraping the mandibular angle and rejoining the bundles of the medial pterygoid on the internal face of the mandible. This periangular masseteric-pterigoid girth was subdivided into jaw bone inserted bundles and bundles with free attachment which were opposed through the meato-angular ligament and the masseteric-pterygoid raphe. However, exchanges between the masseteric and pterygoid bundles were never observed. On a functional basis, the periangluar girth is of great importance.


[Quantitative study on the effects of parathyroidectomy on the osseous remodelling and physiological migration of teeth in the rat]. Numerous hypotheses have been advanced to explain the factors determining the rhythm and direction of the physiological drift of the teeth, but the exact causes of the phenomena are still poorly understood. Since dental mesial drift and alveolar bone remodeling are closely associated, the influence of the parathyroid hormone, systemic factor of bone remodeling, was studied. A cessation of physiological mesial drift was observed in 8 days on parathyroidectomized rats without the use of any direct local action or compression of the periodontal ligament, on the resorbing alveolar side. Parathyroid hormone injection in rats parathyroidectomized for 4 days allowed the development of physiological drift in the same direction. Alveolar bone is therefore parathyroid hormone dependent : the remodeling seemed to determine the physiological drift whereas a local factor seemed to determine the direction.


Influence of the collection and transport of specimens on the recovery of bacteria from peritonsillar abscesses. In 30 patients with peritonsillar abscesses, pus was obtained by aspiration and by taking a swab after incision; bacterial recovery was compared. Although processed in the laboratory within 2 h, swab speciments gave results comparable to syringe specimens in only 9 of 13 patients with beta-hemolytic streptococci and 7 of 25 patients with anaerobic bacteria. Both kinds of microorganisms were lost in some cases but appeared as additional flora in others. The poor results from the swab technique was ascribed to overgrowth of respiratory flora contaminating the sample after incision. In aspirated pus kept in the syringe, or transferred to anaerobic transporters, the microbial flora was unchanged for 24 to 48 h. Some anaerobes also survived on agar slants for 24 h, but specially designed anaerobic transporters are recommended.


Physiological classification of oral viridans streptococci. The human mouth harbors large numbers of a variety of greening streptococci. For many years the classification and nomenclature of these organisms have been confused, but recent studies have clarified the situation considerably. Five distinct species can be distinguished among the oral streptococci S mutans, S sanguis, S mitior, S milleri, and S salivarius, and these may be identified using a simple scheme consisting of seven physiological tests. Further subdivisions within these species may be achieved using serological methods. A small number of oral streptococci remain which cannot easily be identified with existing schemes. These may represent additional species that, as yet, have not been adequately described. There seems little justification for continuing the practive of calling all alpha-hemolytic streptococci simple "Streptococcus viridans".


Antigens and surface components associated with virulence of Actinomyces viscosus. We have isolated a specific cell wall antigen of high molecular weight which appears to be unique to virulent strains of A viscosus and A naeslundii. The antigen is composed of two parts: a polysaccharide moiety containing 6-DOT as the major sugar and determinant of serologic specificity, and a small peptide bearing some resemblance to the peptidoglycan. Other data indicate a positive correlation between the presence of this antigen and an extrachromosomal piece of DNA having most of the properties of a bacterial plasmid. The specific function of the 6-DOT antigen in disease production is not known, but its clear association with virulent strains suggests the possibility of monitoring specific populations of oral actinomycetes.


Antigens from Actinomyces species and their value in identification. Actinomyces have a complex antigenic structure that includes neutral cell wall carbohydrate and some polypeptide containing charged antigens. Wall carbohydrate can be prepared in a relatively pure form from cell walls or by DEAE Sephadex chromatography of acid extracts and supernatant culture fluid. Charged antigens are generally eluted in groups by batch-elution from columns. Cell wall carbohydrate can be responsible for species-specific reactions and cross-reactions, and strains may possess more than one cell wall carbohydrate determinant. The charged antigens also can be species specific, but they cause some cross-reactions, particularly those between the A israelii serotypes. Autoclave extracts of strains, tested against antiserums reacting with cell wall carbohydrate, may be valuable in routine identification of isolates.


Cellular fatty acid composition of Streptococcus mutans and related streptococci. The cellular fatty acid composition of 18 strains of Streptococcus mutans and 17 isolates of related streptococci were examined by gas-liquid chromatography. The cultures could be divided into two distinct groups on the basis of their fatty acids. The first group, which included S mutans and S salivarius, contained palmitic (16:0), octadecenoic (18:1), stearic (18:0), eicosenoic (20:1), and eicosanoic (20:0) acids. The presence of the two 20-carbon fatty acids distinguished S mutans and S salivarius from all of the other species. Two of the S mutans cultures were further distinguished by the presence of 19-carbon and 21-carbon cyclopropane acids. The second group included S sanguis, S mitis, S uberis, and a culture of Lancefield group C streptococci. The percentages of the major acids (16:0, 18:1, and 18:0) found in these species were essentially identical. A culture of Lancefield group E streptococci contained large amounts of 16:1 and 18:1 and small amounts of two unidentified acids which were not present in any of the other cultures.


Enamel corrosion produced by zinc phosphate dental cement. The application of a phosphoric acid solution or of a zinc phosphate cement mix on enamel surface causes alteration of its structure. The lesions of the enamel are cavities of irregular shapes that might retain debris. In view of the high solubility of disintegration of the cement, those cavities can be considered potential sites of plaque installation and initiation of carious processes.


Quantitative stereological investigations of porous alumina implant biomaterials. We made several conclusions from this study on a candidate porous alumina bioceramic. First, the volume fraction of porosity varied from 64 to 79%, whereas Archimedes density shows 62% porosity. Second, the mean lineal intercept and tangent diameter varied from 0.048 to 0.058 cm and 0.034 to 0.040 cm, respectively, and did not provide a good concept of the minimum pore size neck dimensions for the specimen. Third, the pore-size dimension varied from 0.0185 to 0.1157 cm which indicated a minimum pore neck size large enough for tissue ingrowth and ossification if located in bone. Fourth, the pore structure was totally interconnected with considerable side branching and multi-interconnections. Fifth, the serial sectioning of the porous alumina ceramic biomaterial provides considerable insight into the critical features of the material as a candidate for a surgical implant material and a better understanding of the relationships between two-dimensional and three-dimensional structural components.


Development of scales to measure provider attitudes toward expanded duty dental auxiliaries. Much of the research on attitudes toward utilizing EDDAs has been rather haphazard in its measurement aspects. Examining responses to single items or summing across a series of items without any empirical rationale for such summing cannot be justified given current knowledge about measuring attitudes. The scales developed here are appreciably better from a psychometric point of view than scales reported in the dental literature to date. The use of standardized measuring instruments would facilitate cross-study comparisons. Such a process is presently not feasible because each researcher is using his own idiosyncratic scales of unknown psychometric characteristics. The three scales developed here to measure (1) the value of expanding auxiliary functions, (2) patient reaction to the use of EDDAs, and (3) satisfaction with changed dentist role may permit more standardized measurement of at least some aspects of provider and future provider attitudes toward the utilization of expanded duty dental auxiliaries.


A physiochemical approach to the study of amines as antiplaque agents. Alkyl and aromatic amines were evaluated for inhibitory activity against S mutans 6715. Only the alkylamines were active and this may be due to their greater basicity. The agents that showed good activity were decylamine, dodecylamine, tetradecylamine, and hexadecylamine. In addition to the free bases, the hydrochloride and hydrofluoride salts were also tested for inhibitory activity and the same four agents were shown to be most active. These agents appear to hold good promise as antiplaque agents against S mutans 6715, therefore, further in vitro studies against other plaque-forming bacteria and toxicological and clinical evaluation seems to be warranted to determine the best clinical agent.


Effects of cement bases on the stresses and deflections in composite restorations. A model was used to investigate stresses and deflections in cement bases and in a composite restorative material induced in a posterior Class I restoration. Deflections in the composite were highest when it was supported by a base with a low modulus; however, the maximum tensile stress (12 MN/meter2) occurring in the composite restoration at the interface with the base was well below the maximum tensile strength of most composite materials (30 to 40 MN/ meter2). Tensile and shear stresses occurring in the cement bases were of sufficient magnitude to exceed the strength of the cement when a 1.5-mm layer of zinc phosphate cement (base consistency) was supported by a 0.5-mm layer of ZOE lining material. Lowest values of stress were observed when a 2-mm layer of a zinc polyacrylate base was used to support the composite restoration. An ideal situation would be to have a cement base with a modulus of elasticity equal to that of the composite material. Finally, the maximum stress and deflection values obtained here can be easily exceeded in a clinical situation when wider variations can be easily introduced, making the choice of a cement with the proper modulus even more critical.


In vitro interactions between the surfaces of enamel white spots and calcifying solutions. The treatment of white spot enamel lesions with a saturated DCPD solution followed by a high fluoride topical application appeared to produce a surface coating consisting mainly of spherical particles that filled in the honeycombed-etched surface of the untreated enamel white spot. The conditions used in these pilot studies were not ideal to take advantage of the DCPD and fluoride reaction to form FAP. Additional study is warranted on the solution composition and application time along with identification of the reaction products formed.


Examination of the test for compressive strength applied to zinc oxide eugenol cements. The distribution of compressive strength results for a zinc oxide eugenol cement is negatively skewed. However, removal of a small number of outlying low results converts the distribution to a normal one. Crosshead speed and friction at the anvil have no significant effect on results, but compressive strength is a function of the diameter-length ratio of the cylinder and increases with this ratio.


Quasimonochromatic radiation for dental radiography. Because of the greater sensitivity of commonly used dental films near 40 kv and the inherently greater contrast between bone and other oral tissues that is achieved at lower energies than those conventionally used, a considerable reduction of radiation exposure can be obtained by the use of those quasimonochromatic photons whose energy lies between 30 and 40 kv. The simplest and clinically most efficacious and econimical method of obtaining this quasimonochromatic radiation using fixed-anode tubes involves the use of Ce, 0.008 inch in thickness, as a band-pass filter, with reduction of skin exposure by a third to a half. The considerable dose reduction achieved at an increased exposure time of only 1.2 seconds is significant in view of the fact that both a greater percentage as well as a greater number of people are receiving radiation for oral diagnosis every year. Since the quasimonochromatic rays produced are less energetic than much of the radiation in the unfiltered beam, the radiation doses from scattered radiation to skull, bone marrow, and gonads also are reduced. In addition, the softer photons result in less Compton scattering, reducing the fog and improving the diagnostic quality of the film. Quasimonochromatic radiation may also be used to enhance the contrast wherever iodine contrast medium is needed since iodine absorbs very strongly above its absorption edge near 33 kev, suggesting another use of this technique in the area of oral diagnosis.


Fracture properties of human enamel and dentin. Fracture in enamel is anisotropic with respect ot the orientation of the enamel rods, with Wf for fracture parallel to the rods being 0.3 X 10(2) J/meter2 but on the order of 2.0 X 10(2) J/meter2 for fracture perpendicular to the rods. Fractographs of enamel showed that the enamel rods behaved as integral units during controlled fracture. A model was proposed to explain the fracture properties of enamel involving the assumption that the hydroxyapatite crystals did not fracture but that their orientation determined the fracture properties. Dentin was also anisotropic, with fracture parallel to the dentinal tubules being the strong direction - Wf was 5.5 X 10(2) J/meter2 for fracture parallel to the tubules, but 2.7 X 10(2) J/meter2 for fracture perpendicular to the tubules. Wf for dentin was of the same magnitude as the high strain rate Wf found for bone (2.0 X 10(2) J/meter2 [ref 3]). The data obtained in this investigation indicated that dentin and enamel are brittle substances and that forces occasionally imposed during mastication or bruxism probably are capable of initiating fracture when the normal anatomy of the tooth has been altered by cavity preparation. As consequence, the design of cavity preparations should include considerations to reduce stress concentrations and thus improve the practical fracture strength of tooth structure.


Sequential electron microscopic healing study of grafted palatal mucosal. Human palatal mucosa may be glycerolized, frozen, thawed, and autogenically transplanted with success after a storage period. Although tissue damage is observed, both on a light and electron microscopic level, this is not clinically significant. This damage is attributed to the glycerolization, freezing, and thawing processes. As evidenced primarily by our ultrastructural study, regeneration of grafted epithelium is effected via the basal cell layer. The formation of intracytoplasmic vesicular structures and alterations in both the basal lamina and intercellular substances may play a significant role in the regenerative process. The electron microscope has served to elucidate changes in regenerating cells that have not been previously observed by light microscopy.


Relationship between fluoride concentration in enamel, DMFT index, and degree of fluorosis in a community residing in an area with a high level of fluoride. The object of the present study was an attempt to relate fluoride concentration in enamel, caries experience, and the degree of fluorosis in a community residing in an area with a high level of fluoride. A significant difference was found between the male and female samples for the F and D parameters. A positive correlation was established for the male participants between DEGF and F, and a negative correlation between age and F. These correlations were not found for the female participants. Because of the low and narrow range of DMFT indexes, no correlation involving this parameter could be established.


Excretion of barbiturates into induced parotid saliva of the rat. On the basis of the results presented in this study, it has been shown that the five barbiturates studied are excreted into the parotid saliva of the rat. Furthermore, it has been shown that the salivary excretion of these agents, as indicated by their S/P concentration ratios can be correlated with the lipid solubility as indicated by the L/W partition coefficient, and can be correlated to a lesser extent with the degree of drug ionization and plasma protein binding.


Stress concentrations at the apex of pinned, implanted teeth. Stress in the alveolus at the apex is reduced when the implant is held by a pin through the alveolar wall. This stress reduction is effected by transfer of part of the coronal force to the alveolar wall by the pin. Pin positions centrally located between the apex and the alveolar crest provide the greatest reduction of stress concentration in the alveolus at the apex. Since the bone is especially fragile near the alveolar crest, care must be taken when the pin is positioned in this region. Positioning the pin near the apex has the least effect on reducing the stress in the alveolus at the apex. Although no data were obtained relating to stress in the alveolar wall at points of pin penetration, results given here do indicate that from 7 to 30% of the intrusion component of the coronal force is transmitted to the alveolar wall by the pin. Additional research is needed to determine the effects of stress at the pin through the alveolar wall because of load transfer by the pin from the implant to the alveolar wall. The situation in the alveolar wall would be one of creation of a completely unnatural stress rather than reduction of an existing stress, as was the case at the apex. Whether the reduction of stress at the apex and the creation of stress at the pin through the alveolar wall are of physiological benefit is a question that must yet be answered.


Characteristics of an in vitro dental pellicle. Procedures developed for in vitro pellicle formation in intact enamel proved useful for relating qualitiative characteristics of dental pellicle to a number of factors. Coronal surfaces of extracted human molars from experimental and control groups were pumiced, sterilized, and incubated for two hours at 37 C in parotid saliva and distilled water, respectively. Pellicle proteins were desorbed sequentially with water and 0.2 M sodium phosphate, with a pH of 7.0. Polyacrylamide disc electrophoresis of the desorbates yielded distinct patterns, indicating selective adsorption of proteins from saliva, varying affinity to enamel, and the presence of proteins not acquired in vitro from saliva. Certain pellicle components, including amylase and IgA, showed a relatively weak affinity for enamel and were eluted in part by water; other proteins were desorbed only by phosphate buffer. Anionic electropherograms of the phosphate desorbates showed an increase in the two most anodic proteins relative to corresponding salivary bands. An intense anodic protein and two minor bands were eluted by water or buffer from the surface of control as well as experimental teeth but not from teeth coated with sealants. Serum albumin and alkaline phosphatase were identified as components of the extra-salivary material. Further investigation of the sources and functions of the constituents of the protein layer generally considered as "acquired" dental pellicle appears warranted.


Acrylamide gel electrophoretic studies of extracellular sucrose-metabolizing enzymes of Streptococcus mutans. This study explored the use of acrylamide gel electrophoretic methods to determine the numbers and types of extracellular sucrose-metabolizing enzymes produced by particular strains of S mutans. Strains HS-6, SL-1, FA-1, and NCTC 10449 were cultured in a chemically defined medium and the extracellular proteins elaborated by the organisms were isolated and subjected to acrylamide gel electrophoresis. Patterns of protein components and sucrose-metabolizing enzymes were then delineated. Three types of sucrose-metabolizing enzymes were observed. One type was involved in the synthesis of polysaccharides that were insolubilized in the gels. Another type was involved in the synthesis of water-soluble polysaccharides. A third type was involved in the splitting of sucrose into reducing sugars without polysaccharide synthesis. Each pattern was distinctive with regard to the numbers, proportions, and types of enzyme components present and their migratory characteristics. From two to at least six components were observed amont the enzyme activity patterns per strain. Extracellular protein patterns showed from 12 to 20 components per strain. Comparative data on growth in the chemically defined medium and Todd-Hewitt broth were also presented. Better growth levels were obtained in all instances with the chemically defined medium over comparable periods of time.


Dimethacrylates derived from hydroxybenzoic acids. Since the color stabilities and durabilities of current composite and pit and fissure sealant resins need improvement, it is worthwhile to evaluate innovations that might accomplish this goal. Accordingly, three crystalline dimethacrylate monomers with low melting points were prepared from the isomeric hydroxybenzoic acids and 2-bromo-ethyl methacrylate. These monomers can be purified by crystallization and liquified by admixture in various proportions to obtain a polymerizable liquid of suitable viscosity at room temperature. In contrast to the analogous dimethacrylate monomers that were derived from the phthalic acid isomers, these aromatic ether-ester dimethacrylates do not form colored charge-transfer complexes with tertiary aromatic amine accelerators. These monomers and their polymers should be elevated for use in composites and pit and fissure sealant formulations.


Impact of a conference institute taught by individualized instruction. The results indicate that a CI based on individualized, flexible instruction succeeded in aiding acquisition and retention of new knowledge, fostering interactions between dental educators interested in educational research, augmenting a positive feeling toward educational research, and changing the subsequent professional activities of the participants. Data collected and analyzed during a five-year period following a five-week CI on educational research indicate the following: 1. The participants acquire, retain, and use an appreciable amount of information taught in a brief time period. 2. Instructional materials sent in advance for voluntary study have little influence on acquisition of knowledge. 3. Informal interactions between participants are an important part of the learning process at a CI. 4. Activities at the home institution do not shift to new broad categories to any appreciable extent, but changes in specific activities directly related to the goals of the CI were observed.


Xeroradiography in dentistry.

Xeroradiography in dentistry. Extensive review of the literature reveals that the diagnostic benefits of xeroradiography in medicine are rapidly being recognized. It is viewed with particular interest by clinicians managing neoplasms of the laryngopharyngeal, mammary, and joint regions. Xeroradiography is a definite aid in cephalometric analysis. Examples of use have been presented. The main disadvantage of xeroradiography in dentistry is that of slow-speed developing in comparison with that of our current silver halide films. This becomes significant when dealing with intraoral films. However, the only disadvantage that we have experienced with xerocephalometrics is that of head orientation. Because our radiology department is not equipped with a wall mount for proper alignment along the horizontal and vertical planes, the head position must be estimated with a plumb line. Very often, therefore, the head may be tipped in one direction or another. This, however, is not difficult to correct. I have noted several definite advantages that include: --Sharp, clear-cut contrast (because of the edge effect), which enhances image quality. --Simplified viewing (no need for view boxes). --Less radiation than that required for conventional radiographs. Because of the benefit of multiple-tissue diagnosis on one radiograph, there is no need to take multiple radiographs to record tissues of different densities, with the possible exceptional of special situations in tomography. --Dry, automatic processing, therefore, eliminating the need for mixed chemicals and darkroom. --Less cost to produce a xeroradiograph than a conventional radiograph because of the lower cost of materials and equipment (for example, no darkroom requirement). The Russian investigators reported an eightfold reduction in cost. Xeroradiography (from Greek word xeros meaning dry) is a radiographic process in which the quality is critically dependent on the potential of the surface charge on the plate, the amount of radiation exposure, and the conditions of development, all of which must be carefully controlled. This technique is gaining general acceptance. Special courses are being offered to teach technicians this process. I believe we have come on a new horizon in diagnostic radiography. Only through further investigation and research will we be better able to delineate the exact role of xeroradiography in dentistry.


Dentistry and the county home resident: a statewide survey. A flow chart (illustration) depicts the delivery process whereby county home residents either receive or do not receive dental treatment. Also included are the major findings of the survey, given in triangles A, B, and C. The initial step involved in this delivery process is that of recognizing a need. If the need is not recognized, it remains unmet and the patient receives no treatment (terminate). If the need is recognized, a treatment decision is required. If the decision is negative, the need remains unmet and the patient receives no treatment. If the decision is positive, the patient proceeds toward the goal of receiving dental treatment. However, potential delivery problems exist and the patient may have to overcome one or more of these before proceeding toward the goal. If problems do exist and are not resolved, the patient either does not receive treatment or treatment is delayed until satisfactory solutions are found. The first finding, A, shows that more than 72% of dental needs were identified because of some dental emergency experienced by the patient, 39.3% of needs were identified through routine checkups, 16.4% by a county home requirement, 14.8% through a state requirement, and 4.9%, "other." The second finding, B, shows that the county home steward makes the decision about whether dental treatment should be rendered in more than 85% of the homes. Physicians made 54.1% of the dental treatment decisions; nurses, 31.1%; dentists, 26.2%; patients, 24.6%; patient's family, 13.1%; supervisor or trustee, 4.9%; and "other," 3.3%. The third finding, C, represents delivery problems. More than 44% of the stewards said that the patient's mental or physical disabilities were a delivery problem; 39.3% indicated availability of dentists; 36.1% said reluctance of patient; 19.7% responded inadequate funding; and 14.8% indicated "other." A hypothetical county home resident can be dentally characterized as an emergency patient whose need for treatment is determined by a county home steward, and the main problem in obtaining treatment, according to the steward, is the patient's own inability to receive treatment because of mental or physical disabilities, or both.


High blood pressure detection: a new public health measure for the dental profession. Detection of high blood pressure can be a major public health service contribution by the dental profession. The pioneer program at Fairleigh Dickinson University, in conjunction with the Bergen County Health Department and the Bergen County Dental Society, is encouraging dentists to participate in the National High Blood Pressure Program. Participants are urged to measure the blood pressures of all their adolescent and adult patients and to refer those with sustained elevated readings to their physicians, preferably by the arrangements of appointments.


Abbreviated periodontal examination.

Abbreviated periodontal examination. The prevention, detection, and treatment of periodontal disease should be among the foremost goals of dentistry. When a systematic examination is used, detection of the disease need not be a lengthy or cumbersome procedure. The mesiofacial aspect of every tooth should be probed and recorded. The integrity of all furcations should be carefully checked, mobility patterns should be recorded, and the patient should be examined for any mucognigival problems. If any of these problems are detected, the clinician must decide whether he will treat the problem himself or refer the patient to someone else. The important thing is that periodontal disease has been recognized and can, therefore, be dealt with.


Traumatic cyst of the jaws: report of 30 cases. A clinicopathologic study was made on 30 cases of the traumatic bone cyst of the jaws, and these observations were recorded. --The lesion is one of skeletal-wide distribution, but in the jaws it occurs most frequently in the posterior portions of the mandible. --The majority of cases are not associated with trauma, and the lesion is most commonly detected in routine radiographs. --The median age of this series of patients was 20 years, and the majority of patients in this series white men. --Histologically extravasated red blood cells, degenerating fibromyxomatous tissue both inside and outside of bone, hemorrhagic membranes, and other changes consistent with degenerative processes were observed. --The origin of the traumatic bone cyst was not determined in this study, but histologic evidence pointed toward a degenerative process that also could not be adequately explained; therefore, the more general term solitary bone cyst is suggested for use. --Treatment of the solitary bone cyst consists essentially of exposing the lesion and mild curetting to produce a clot formation that will subsequently organize and fill in with new bone.


Point and interval estimation in the combination of bioassay results. A procedure for combining evidence from different biological assays is shown to be equivalent both to generalized least-squares and to maximum-likelihood estimation. By appropriate nesting of hypotheses, the likelihood function can be used to test the agreement between the assays and to obtain probability limits for the combined estimate of potency. The properties of these limits are examined, with particular reference to the situation, unusual but not impossible in practice, in which the values of relative potency that they define consist of several disjoint segments instead of a single interval. The connection with general theory of estimating linear functional relations is pointed out.


Investigation of cross-infection in isolation wards of different design. A survey was conducted in seven hospitals to assess the risk of cross-infection with the highly infectious air-borne diseases, varicella-zoster and measles, in isolation wards of different design. Existing wards and isolation techniques were found to afford a high degree of protection, but there was considerable variation in the incidence of cross-infection related to ward structure, ward practice and the availability of trained staff. Recommendations are made for the design of new isolation wards and for safe practice.


Role of rubella in congenital malformations in India. In the present study rubella HI antibodies were determined in cases of congenital malformation and bad obstetric history to determine the role of rubella in such cases in India, as it has been reported to be rare in Japan in contrast to Western countries. The incidence of antibodies was statistically significant in cases of congenital eye, C.N.S., visceral and miscellaneous malformations and cases of spontaneous abortion and still-birth compared with controls of matching age groups. This is further supported by the demonstration of IgM antibodies in seven cases of congenital malformations and ten cases of spontaneous abortion. Our findings show that congenital rubella is not rare in India.


A contribution to the primary reconstruction of the upper lip and labial commissure following tumour excision. Two procedures for the primary reconstruction of the upper lip and corner of the mouth following tumour excision have been described in the paper presented. One method represents a modification of Burow's technique (1855) for the reconstruction of the lower lip, which is very suitable in the reconstruction of the lateral border of the upper lip. The second procedure is best suited for the remoulding of the area of the angle of the mouth. The tumour is excised in a crescent-shaped manner, and the missing upper and lower lip reconstructed by means of a horizontal incision in the cheek, and de-epithelisation of two triangular areas which are covered with undermined buccal mucosa. The incision lines described have been illustrated in two cases.


Late results after advancing the mandible by sagittal splitting of the rami. 38 patients have been followed up for at least 2 years, and in the mean 5 years after surgical correction of retrognathia. The technique used was the sagittal splitting of the rami (Obwegeser 1955, 1957) usually with the modification of the lateral cortical bone cut of Dal Pont (1959). 26 patients showed no changes compared with the early postoperative result. In 8 other cases, the horizontal overjet increased up to 3 mm without impairment of the aesthetic or functional result. Therefore the operation may be considered successful in 90% of cases. Four severe relapses were noted. They are at least partially caused by poor repositioning of the condyle-bearing segment during operation. Reduced function of different degrees was seen at the late check-up in 20% of the mental nerves. 45% of the patients have cracking in the temporomandibular joint. Causes and possible late consequences are discussed. To conclude, the sagittal splitting of the rami for the forward movement of the mandible as the standard method of our clinic seems justified.


New guiding principles in the treatment of clefts. Breathing through the nose with the mouth shut is essential for the normal development of the facial region related to the mouth and nasal cavities and for the normal development of the two cavities named. Surgical treatment of unilateral total cleft practised hitherto calls for the closure of a cleft in the lip and a cleft in the alveolar ridge at the same surgical intervention. In the great majority of cases a combined intervention closes the respiratory pathway, which was established through the cleft nasal floor and alveolar ridge after birth. From the first surgical intervention on, the child is forced to breathe through the mouth. The disruption of the normal functional development mechanism causes the formation of the characteristic physiognomy of a child with a cleft. The correct treatment as presented in this paper, must consistently observe, in addition to other no less important principles, the primary principle: it is essential for a child with cleft to be made to breathe through the nose with the mouth shut, as soon as possible. The operative plan of treatment must help a child with a cleft to create, by utilizing the natural development abilities, and with minimal application of trauma, the same conditions for the functional development mechanism as are possessed by a healthy child of the same age. The enclosed evidence proves the validity of the described guiding rules, and affirms again the well known principle that only normal function produces normal form.


Maxillary alveolar hyperplasia, diagnosis and treatment planning. Literature pertaining to studies of the vertical relationships of the facial skeleton, the dentition, and the lips is reviewed. A surgical procedure for superior repositioning of the total maxillary alveolus is presented. The usefulness of the procedure to correct maxillary alveolar hyperplasia is illustrated with two case reports.


Visor osteotomy to increase the absolute height of the atrophied mandible. A preliminary report. A method of operation is described whereby the alveolar ridge of the mandible is osteotomised and moved on the principle of a visor. The two parts are fixed together with wires, thus increasing the absolute height of the alveolar ridge of the mandible.


Topographical anatomy of the total osteotomy of the midface. In this study, the operating conditions for total osteotomy of the middle part of the face have been simulated in a cadaver and the topography of the organs at risk has been examined. The area of the maxillary tuberosity is the region which is mainly exposed to considerable injury to vessels; here an uncontrolled fracture as compared with a systematic osteotomy is the safer method under the given anatomical conditions.


Surgical removal of orbital osteoma; case report. Thr authors report a patient with a large orbital osteoma causing marked physical deformity and diplopia but with preservation of visual acuity. A combined transorbital and transcranial operative approach was used for total tumor removal and cosmetic repair.


Mechanisms of early maxillary growth-implications for surgery. Previous studies of the effects of surgical techniques on facial growth (with one exception) have been done in dogs, pigs, rabbits, and rats; the phylogenetically closer nonhuman primate serves as a better model. Current data, obtained from resection of the nasal septum in baboons, indicate that proper coordination of timing and surgical technique can cause arrest of growth in the upper part of the face.


Secondary correction of nasal abnormalities associated with cleft lip. Approximately 30% of patients will require a second operation for correction of nasal abnormalities associated with unilateral cleft lip. In a single second operation, the following steps seem to give the most satisfactory correction: repositioning the nasal septum in the midline; altering the contour of the alar cartilage on the cleft side; and rotation of the axis of the external naris on the cleft side. The usual result following this combination of procedures is moderate but not complete correction of the abnormality. About 50% of the patients will need a second operation for correction of nasal abnormalities associated with bilateral cleft lip. Satisfactory correction of the bilateral cleft lip nasal deformity is usually obtained by lengthening the columella (which secondarily corrects a flat nasal tip) and narrowing the width of the nose at the level of the alae. Satisfactory restoration to normal is usually obtained by the aforementioned procedure.


Interdental osteotomy for immediate repositioning of dental-osseous elements. The treatment of crowded, poorly aligned, and spaced teeth is most commonly accomplished by orthodontic means. Interdental osteotomy offers a method for the immediate repositioning of dental-osseous elements that may serve as an aid to orthodontic treatment or be used as an independent procedure. The history of the procedure, its indications, planning considerations, surgical methods, and case results are presented.


Combined anterior and posterior maxillary osteotomy. The combined anterior and posterior maxillary osteotomy is primarily indicated for maxillary alveolar hyperplasia. Treatment planning is somewhat more complex than usual for the combined procedure. A method for developing a treatment plan is presented. In contrast to the anterior maxillary osteotomy, the technique for posterior osteotomy is relatively new and has had several recent modifications. Guidelines are presented for rational selection of a specific combined technique. The results obtained with the combined technique have not been well documented. Nonetheless, results appear to be stable and complications are infrequent.


Psychological considerations in corrective maxillary and midfacial surgery. For the majority of patients with dentofacial deformities, surgical correction results in improved reactions to one's environment. In a few instances, this emotional improvement is lacking or is minimal and may result in a patient's dissatisfaction. The results of evaluation of several specific factors may be used to classify patients into three groups according to probable risk of dissatisfaction. Some negative reactors will respond to supportive measures specifically designed to aid in achieving a smooth postoperative course. In others, surgery should be undertaken only with the close cooperation of a psychiatrist, although occasionally surgery should be deferred indefinitely. By making a planned attempt to evaluate the patient's psychological status and dealing appropriately with that evaluation, the surgeon may increase the number of patients who respond favorably to his treatment and therefore increase his own satisfaction as well.


Modification of the sagittal ramus-split osteotomy for retrognathia. A modification of the sagittal ramus split osteotomy for mandibular advancement has been described. It prevents rotation of the distal fragment, simplifies fixation, and reduces lateral pharyngeal edema.


Dislocation of the condyle into the middle cranial fossa. Surgical intervention by a preauricular approach appears to be the preferred treatment in this rare injury. It does not appear necessary or wise to disimpact the condyle as it presents more of a surgical risk and its presence in the cranial fossa seems to pose no neurological problems. The use of an interposing medium, placed after the teeth are secured in occlusion, appears to be definitely indicated to prevent ankylosis and, hopefully, to eliminate deviation of the mandible. A carved piece of Silastic, designed to conform to the recontoured roof of the glenoid fossa, has produced excellent results in cases of ankylosis; it served well in this case. Silastic has the advantages of being easy to carve, it may be attached to the rim of the fossa, and it is extremely nonirritating; it eventually becomes encased in a fibrous capsule.


Acute myelogenous leukemia in children: a preliminary report of combination chemotherapy. Twenty-four children (2 to 21 years) diagnosed as having AML from 1969 to 1972 were randomized to receive either a single combination (COMP or PRAVD) or sequential combination chemotherapy (alternating POMP and PRAVD). Seventeen achieved complete remission. Patients who received POMP alone had the longest median duration of remission (1,400 days) compared to PRAVD (395 days) or POMP-PRAVD (270 days); interpretation of this difference is uncertain, since the numbers in each group are small. Fifteen patients have relapsed, four initially with CNS involvement. Successful reinduction was achieved almost exclusively for patients who had initially received POMP. Survival after first relapse was short. Patients less than 16 years had a median survival of 632 days, compared to 285 days for patiens greater than 16 (p less than 0.05). The high initial induction rate in these patients is encouraging, but the duration remission is inferior to that seen in childhood ALL. Moreover, the slope of the relapse curve is continuous over a five-year period with no definite plateau where it might appear that patients are no longer at risk of relapse. Improved methods for the treatment of childhood ALL and adult AML suggest possible new approaches to AML in children, with prophylactic treatment of central nervous system, late intensification, and immunotherapy.


Reversible dementia temporally associated with intraventricular therapy with methotrexate in a child with acute myelogenous leukemia. During maintenance therapy with intraventricular methotrexate, progressive dementia developed in a child with meningeal leukemia. Cerebrospinal fluid levels of MTX were in the nontoxic range and neurologic evaluation failed to demonstrate anatomic obstruction, infection, or folate depletion. The patient's symptoms gradually resolved when the methotrexate was discontinued, suggesting that methotrexate neurotoxicity may occur in the absence of an elevated CSF concentration of MTX.


Influence of a chlorhexidine and a zinc mouthrinse on gingivitis. The end point methodology did not indicate a difference between the agents. The prophylaxis effect was only demonstrable through 8 weeks, although the analysis of variance indicated a prophylaxis effect on gingival index throughout the study. An agent effect was not demonstrable in the study. The "positive control," chlorhexidine, did not give the same results in this brushing study as in previous no-brushing studies reported by Loe and by our group. One might conclude that the effectiveness of brushing in reducing gingivitis is greater than the effect of chlorhexidine. Decreasing plaque and gingivitis scores are seen with increasing time, probably reflecting increased subject interest and involvement in the study. Mere involvement in the study apparently produced a beneficial effect on gingival health. This "placebo effect" also has been noted in an earlier study. A similar decrease in plaque scores in a placebo group attributable to a general improvement of oral hygiene was reported by Gjermo and Rolla. The subjects who began the study with no calculus (prophylaxis group) had consistently lower calculus scores than those not given a prophylaxis. This difference became less distinct at later exams, as the treated group developed calculus. The agents, although ineffective under the test regimen produced no adverse effects.


Necrotizing ulcerative gingivitis in children: a 9 year clinical study. Twenty-eight children with ANUG and nine children with noma were studied over the past 9 years. It is concluded that these entities occur only in children from low socioeconomic groups and have a multifactorial etiology consisting of poor oral hygiene and malnutrition. In the case of noma, a prior infection with a viral agent or intestinal parasitism appears to be important predisposing factors.


The relationship of 17-hydroxycorticosteroid to acute necrotizing ulcerative gingivitis. Eleven patients presenting with acute necrotizing ulcerative gingivitis (ANUG) collected 24-hour urine samples during and after the course of their ANUG. The Porter-Silber technique was used to determine the 17-hydroxycorticosteroid concent of the urine, a physiological measure of stress. All of the patients had significantly higher levels of 17-hydroxycorticosteroid during the course of their ANUG than after it had resolved.


Uremic stomatitis: report of a case.

Uremic stomatitis: report of a case. A case report has been presented demonstrating the influence of chronic renal failure in the development of oral disease. Uremic stomatitis is a disease entity that requires both local and systemic therapy. The primary emphasis is directed toward the correction of the systemic pathology for proper resolution of the oral condition.


The prevalence of periodontal disease in a selected dental population. Sixty-five dental personnel, who presented for voluntary examination at a periodontal screening center, were assessed for plaque accumulation, gingival soft tissue changes, gingival recession and pocket depth. The relationship of these parameters to one another and to a variety of oral hygiene techniques was analyzed. Positive correlations were found between pocket depth and soft tissue changes and also between some of the parameters and use of an interdental stimulator or an oral irrigating device. The nature of the results is discussed.


Split thickness flap, apically replaced, with protected linear periosteal fenestration. The split thickness flap, apically replaced, with internal linear periosteal fenestration, is a combination of two known techniques. This procedure is another choice to solve mucogingival problems. The advantages in addition to securing a firmer bond of periosteum to bone and mucosa to periosteum at the selected position are: there is no bone exposed, healing is apparently faster and postoperative pain is minimal. An experimental work, carried out on dogs to study the histological reactions after this procedure, is in progress. The results of these observations will be reported in a future publication.


The accuracy of the Schei ruler: a laboratory investigation. A study has been carried out to assess the accuracy of the Schei ruler for measuring the amount of alveolar bone loss from radiographs. A dried human mandible was used for the purpose of this study. A preliminary test was conducted to achieve a standard radiographic technique. Two sets of radiographs were taken of anterior and posterior segments after successive modification of the height of the alveolar bony crest. These heights were measured directly and also by means of the Schei ruler for each stage, using first the root length, and secondly, the total tooth length, as references for obtaining the percentage of remaining alveolar bone. There are two points which may be concluded from this investigation: 1. The ruler proved to be a sensitive tool for measuring the amount of alveolar bone loss as well as being efficient in this application because of its simplicity and ability to give direct readings of the percentage of the bone lost (or remaining). 2. The use of the total tooth length as a reference for the percentage bone loss, overcomes the difficulties of locating other reference points.


The relationship between dialy sperm production as determined by quantitative testicular histology and daily sperm output in the stallion. The relationship between daily sperm productions (DSP) and daily sperm output (DSO) was determined in eleven stallions. The DSO was determined by collecting single ejaculates, with an artificial vagina, at 24-hr intervals. The stallions were killed 24 hr after the last collection and the DSP was determined by quantitative testicular histology. The mean DSP was 8-0 X 10(9) (S.E. +/- 0-4 X 10(9), and the mean DSO was 7-0 X 10(9) (S.E. +/- 0-4 X 10(9)). It was estimated that 87% of the spermatozoa produced by the testes were harvested. The correlation between DSP and DSO was 0-80 (P less than 0-01), and between DSP and testis weight was 0-77 (P less than 0-01).


Results of long-term storage of stallion semen frozen by the pellet method. Stallion semen frozen by the pellet method showed no significant loss of sperm motility and fertility over long periods of storage in liquid nitrogen. Eighteen of thirty mares conceived after insemination with semen recovered in nine ejaculates from seven stallions and stored for 18 months to 7 years.


Results of insemination of mares with fresh and frozen stallion semen. Artificial insemination using deep-frozen semen was performed on 116 mares in 1973 using twelve ejaculates from eight stallions of the Hanoverian breed. Despite the fact that the quality of the semen used was poor, the majority of the mares inseminated were subfertile and some mares were inseminated during one oestrus only, 44% nevertheless conceived and gave birth to live foals. Of a small group of ten mares inseminated in the same year with fresh semen, seven conceived.


Results of artificial insemination of horses in Poland in the post-war period. Artificial insemination (A.I.) of mares in Poland has not yet been widely applied. Initial attempts were made by research groups between 1945 and 1955 but A.I. of mares was only introduced into the normal practice of A.I. Centres during 1964-67. Intensive research into methods for preserving stallion semen in liquid nitrogen has been undertaken since 1968. Of the total of 3734 mares artificially inseminated in Poland since 1945, 350 were inseminated with frozen semen. The slow progress of A.I. in horses is imputed to the small numbers of people involved in the work, to the conservation of the authorities responsible for breeding, to the wrong choice of stallions for A.I. Centres and, most importantly, to the lack of a simple and reliable method of preservation of stallion semen.