A retrospective study of recurrent herpes labialis (RHL) in a professional population, 1958-1971.

A retrospective 12-year investigation of 1,788 professional school students from the schools of medicine, veterinary medicine, dental medicine, nursing, and dental hygiene was conducted by the mailed distribution of questionnaires requesting information on current and prior disease history of recurrent herpes labialis (RHL). Because of changes in address, death, loss of married names, and unwillingness to participate in the investigation, only 683 proband subjects were available for the follow-up study. The data suggested a trend toward a decrease in the prevalence and severity of RHL during the interval of study: only slightly more than one firth (23.9 per cent) of the proband population of the present study experienced RHL as compared with almost two fifths (39.6 per cent) at the time when they were students.


Intraosseous benign neural sheath neoplasms of the jaws. Report of seven new cases and review of the literature.

Benign neural sheath neoplasms occurring centrally within the jaws are most uncommon. Our search of the English-language literature revealed twenty-eight previously reported cases. Seven additional cases--five neurofibromas and two neurilemmomas--are newly described here. Most cases have not been associated with multiple neurofibromatosis. These tumors occur predominantly in females, in patients under 45 years of age, and in the posterior mandible. The tumors generally present as asymptomatic radiolucencies, but some are associated with pain and/or swelling. Neurofibromas tend to recur more often than neurilemmomas when treated by conservative local excision.


Ultrastructure of oral squamous-cell carcinoma.

Fresh surgical specimens of sixteen cases of oral squamous-cell carcinoma were processed for electron microscopic study. All cases were histologically graded as moderately differentiated carcinoma. As compared to normal oral stratified squamous epithelium, some unusual ultrastructural features were present in carcinoma. These features were spherical or ovoid nuclear bodies composed of concentrically arranged filaments and granules, clustered ribosomes, many lysosomal bodies, cell residues in other cells, absence and multilayering of basal lamina, pseudopodal cytoplasmic projections, microfilaments in peripheral cytoplasm, clusters of swirled tonofilaments, intracytoplasmic desmosomes, and a small amount of glycogen. These features are interpreted as being related to hyperactivity, phagocytosis, locomotion, and differentiation of cancer cells.


An ultrastructural study of the calcifications in calcifying odontogenic cysts and odontomas.

The calcifications associated with the epithelium of the calcifying odontogenic cyst and odontoma were studied ultrastructurally and found to be of three types: (1) spherical calcifications which form on ghost cells and which therefore are dystrophic, (2) spherical calcifications which appear to be dysplastic enamel, and (3) irregularly shaped, diffuse calcifications which form on a collagenous matrix and appear to by dysplastic dentin or cementum.


Clinical and histologic observations of opalescent dentin associated with enamel defects.

The rare variant of opalescent dentin associated with enamel defect was found in a 1 1/2-year-old boy. The pulp chambers and root canals of the affected deciduous teeth were very large, with no sign of obliteration. The enamel layer of those teeth was markedly reduced in thickness, and the enamel prisms were not recognized even by scanning electron microscopy. The mantle dentin was abnormal, as were other portions of dentin.


Evaluation of débridement techniques for endodontic instruments.

Files, reamers, and Hedström files were used to instrument both wet and dry canals and then cleansed by a chairside technique. Statistical analysis of the various cleansing techniques showed that 2 by 2 inch gauze wipes, either wet or dry, cleansed the instruments of debris better than any other means tested.


Osteosarcoma.

Significant advances are being made in the treatment of osteosarcoma and improvement in the five year survival is being reported. Active study of the etiology, pathogenesis, immunology, immunotherapy, radiotherapy, chemotherapy, and surgical management is currently in progress. The preliminary survival statistics with adjuvant chemotherapy or immunotherapy are encouraging and it is hoped that these survival figures will be maintained with further follow-up. Our experience suggests that, when practical, patients with osteosarcoma should be treated in or in cooperation with centers actively involved in the evaluation of osteosarcoma therapy. Not only does this step offer the patient optimal opportunity to receive the most current therapy, but it is essential in obtaining adequate numbers of patients for critical analysis.


The radiology of bone and soft tissue sarcomas.

Solitary lesions of bone often have characteristic radiographic patterns that suggest the diagnosis of a specific bone tumor. Differentiation of tumor from infection, however, frequently may be impossible, and the majority of bone lesions require biopsy for histologic confirmation of the type of tumor or for identification of the infectious organism. Soft tissue masses, unlike bone tumors, most commonly look alike. They too require biopsy, but in this case to distinguish a benign mass from a soft tissue sarcoma. Special radiographic techniques such as isotopic and CAT scans or angiography add information about the morphology and response of adjacent bone, but fail to differentiate one category of disease from another or to establish a histologic diagnosis of the type of tumor.


[Treatment of acute leukemia].

Evaluations of 650 patients with acute lymphoblastic leukemias (A.L.L.) and of 596 patients with acute granulocytic leukemias (A.G.L.) ara analyzed. The patients were treated in the department of Professeur Jean Bernard at Saint-Louis Hospital between 1964 and 1976. In A.L.L., prognosis is influenced primarely by age, being worse in infants less than 1 year old and in adults: it is also influenced by the blastic load and by other parameters such as cytology and immunological markers which could not be studied in all patients. The correlation between high blastic load and the T lymphoblasts variety is noteworthy. Random studies are still necessary to find out the best drug combinations and the optimal duration of treatment, but the necessity for meningeal prophylaxis, reinduction treatments and of L-A sparaginase consolidation is no longer discussed. Prognostic stratification is useful for therapeutical evaluation and should load to therapeutical modulation. In acute granulocytic leukemias, age is also a significant parameter and remission rate is lower for patients over 50 years of age. Cytology and cytochemistry allow to recognize acute promyelocytic leukemias and acute monoblastic leukemias which bear specific initial risks (D.I.C. for A.P.L., renal failure for acute monoblastic leukemia) but which are highly sensitive to Daunorubicin and Rubidazone respectively. In A.M.L. remission duration is not influenced by age and seems to be improved by intermittent treatment. The role of immunotherapy is still under study.


[Malignant blood dyscrasias occurring during immunosuppressive treatment. 4 New cases (author's transl)].

In the first 3 cases, the initial disorder was a renal problem (glomerulonephritis, renal homograft). The development of secondary neoplasms appeared to be related to long term immunosuppressive therapy. By contrast, in the fourth case the primary disease was already malignant in nature (breast neoplasm) and treatment was mixed (radiotherapy and chemotherapy). In the light of these cases, the risks of treatment using immunosuppressive chemotherapy should not be neglected.


Basophilic differentiation of chronic myelogenous leukaemia cells in vitro.

Peripheral leucocytes from 10 patients with chronic myelogenous leukaemia (CML) were cultured in liquid medium and observed morphologically for 6 to 10 weeks. All cultures showed in increased proportion of mature basophilis at about 3 weeks and most cultures consisted  predominantly of mature basophilis at about 5 weeks. The results indicate preferential basophilic differentiation of CML leucocytes in vitro and are consistent with basophilia frequently observed in CML patients.


[The determination of plasma proteolytic activity].

Experience with different peptide substrates for coagulation and fibrinolysis is reported. As the specifity of these substrates is relative, appropriate characterization of the proteolytic activity of defibrination syndromes is only achieved by simultaneous assays with various substrates. The influence of contact activation on blood sampling must be strictly defined.


[Bite plates and occlusal splints].

Occlusal adjustments are often necessary in cases of masticatory muscle spasm, bruxism, traumatic occlusion and TMJ disturbancies. Before such occlusal adjustments are performed, the patient should either wear a bite plate or an occlusal splint which frees the occlusion for a certain time. The splint is fabricated on a semiadjustable articulator such as the Hanau H2-XPR which is also used for the functional analysis on the models prior to any adjustments. Advantages and disadvantages of different types of plates and occlusal splints are discussed. The authors conclude that an occlusal splint covering the entire dental arch, such freeing the occlusion, seems to be the most appropriate appliance available today.


[Animal experimental studies on a new dentin and pulp-protective lacquer (Bayer D-520)].

In an ADA experiment on the protective qualities of a new polyurethane varnish (D-520 Bayer) 72 class 5 cavities were prepared on 3 monkeys and treated by the following 4 methods: -- 18 silicate cement (Bio-Trey) with varnish -- 18 silicate cement (Bio-Trey) without varnish -- 18 composite (Adaptic) fillings with varnish -- 18 composite (Adaptic) fillings without varnish. After an observation time of 14 days, a significant positive result for the 520 varnish could be obtained. An experiment lasting 12 weeks was subsequently undertaken.


[Consumption of drinking water by workers in a steel foundry during working hours in Hungary].

In a former paper the authors had investigated the fluorine intake per kilogram body weight and its extreme possibilities. This study includes 97 workers of a steel foundry. The amount of liquid ingested during working hours was measured, for 30 persons in summer during 90 days and 67 persons in winter during 201 days. Inside and outside temperatures were recorded. The mean age was 40,02 years. The mean intake of drinking water was, in summer 3732 ml (+/- s 1176 and +/- sx 123 ml) and in winter 1835 ml (+/- s 684 and +/- sx 48 ml). The mean value was 2422 ml and the extreme values were 500 and 8500 ml. The calculation of the individual mean values showed however, that the water intake follows an irregular pattern of distribution. About 11% consumed more than 41, and about 2% more than 51 per day continuously. In this study, there are those who consume habitually little, more and a lot of drinking water. With the results, the authors are examining the possibilities of the maximum fluorine intake.


Probable myeloblastic leukemoid reaction with disseminated sarcoidosis.

A 55-year-old woman had progressive weakness, weight loss, night sweats, fever, right-sided facial weakness, and hepatomegaly. Reticulonodular infiltrates were seen on chest x-ray film and a central filling defect was noted on liver scan. Study of the peripheral blood was noted on liver scan. Study of the peripheral blood revealed pancytopenia and myeloblasts. The bone marrow was not markedly hypercellular but contained noncaseating granulomas and myeloblasts. The patient's condition deteriorated and she died on the 22nd hospital day. Autopsy disclosed disseminated sarcoidosis but no evidence of leukemic infiltrates. Although concomitant "smoldering" acute leukemia cannot be ruled out, the findings in this patient can be best explained on the basis of a myeloblastic leukemoid reaction accompanying sarcoidosis.


[The etiology of denture stomatitis from a gerontological-stomatological point of view].

The aetiology of denture sore is discussed from the aspect of changes in the keratinizing squamous epithelium of the oral mucosa that are caused by age and hormonal effects. An important rôle must be attributed to Candida albicans, the growth conditions for which increase in general with increasing age. Many cases of denture sore are, therefore, cases of candidiasis which may occur in a chronic, an acute and a pseudomembranous form. The improvement of oral hygiene and denture cleanliness is of prime importance to therapy.


[The possibility of prosthetic treatment of diastema].

In so-called late cases, the correction of a diastema will frequently be achieved only by prosthetic measures, co-operation with an orthodontist being recommendable. The various possibilities of treatment are represented by case reports.


[Intraoral bite registration by means of a recording instrument of the author's own construction].

A method for relation determination in full denture prosthesis is described in the present paper. The centric relation is determined by recording the Gothic arch by means of a self-made instrument. The supporting pin is mounted elastically and telescopically and can be interchanged whereby the instrument is also suited for control recordings. The recording method seems to be especially suited for patients with "orofacial dysfunction syndrome".


[A new form of endosseous titanium hemi- implantation and study suggestions aiming at physiological healing].

Bearing in mind the favourable force distribution of the hitherto currently used blade implants and allowing for the Second Symposium on Maxillofacial Surgery at Warnemünde in 1976, the authors devised a technique in which a titanium implant is placed. This procedure promises in the main three advantages: 1. No wedging action on the bone during operation and during mastication. 2. Better force distribution. 3. The mucosa-periosteum suture no longer coincides with the bone groove required for implantation. Furthermore, the authors deal with techniques for coating the titanium angle implant to achieve biological healing.


[Notes on the current discussion on the etiology of periodontopathies].

The aetiology and the therapy of periodontal diseases are main points of stomatological research. As to the methodological approach to aetiological studies, the use of materialistic dialectic proves profitable. For example, conclusions as to therapy result from the exact analysis of and the distinction between the causes of a disease and the pathogenic factors. In this way the exact evaluation of the importance of the known pathogenic factors becomes possible. The concept of multicausality proves to be unfavourable for the orientation to priority problems in aetiological research.


[Conservative periodontal therapy and its indication in stomatological general practice].

The term of "conservative periodontal therapy" covers all therapeutical measures with the exception of surgical interventions. Since each periodontal therapy constitutes a complex of various measures, it seems to be more favourable to subdivide it, on principle, into continuous phases, which results in advantages for the methodics of treatment planning and performance. The contents of the hygienizing, correcting and stabilizing phase of periodontal therapy are expressed in words and tables.


[The importance of the method investing for accuracy of Sipal inlays].

The fit of three-area inlays (phantom) made from Sipal 306 was determined in an experimental study by means of microscopic measurements of the gap width. Six different investment techniques were compared. The necessity of processing Expansit adequately is emphasized. Core embedding using the LAW precision-casting investment compound is recommended.


[The diagnosis of initial carious changes].

On the basis of radiological studies on extracted teeth and of microscopic examinations of longitudinal ground sections it is stated that the early stages of dental caries are very difficult to diagnosticate clinically. Under the microscope, "healthy" teeth may also show initial carious lesions in the fissure region. The greater frequency of these changes (which might be considered to be premorbid conditions) in teeth with narrow fissures was not significant. For various reasons discussed in the present paper, it can be assumed that teeth with large fissures are earlier and more frequently prone to carious lesions.


[Results and experiences with automatic data processing of caries epidemiological data].

The authors report of further results from and experience with the automated processing of caries-epidemiological data by means of the R 300 computer. The extension of result documentation to qualitative characteristics of caries incidence in the framework of scientific problems is described and critically evaluated, taking a caries-protective collective action for an example.


[Radiographic magnification technique with a high-speed rare-earth screen-film system (author's transl)].

The advantages of radiographic magnification technique - better detail recognition and improved contrast with an enlarged field of vision - should prove an important supplement to the properties of a high-speed rare-earth system - low-current intensity, low voltage, short exposure time and, consequently, lower irradiation dosage. Physical measurements of the Wiener spectral value, MTF and HD curve proved the superiority of the radiographic magnification technique in combination with a rare-earth screen-film system as compared with a conventional system (Dupont Par speed screen, RP films). Phantom radiographs confirmed these results. The clinical usefulness of this method was assessed with respect to the detection rate of gall-stones by means of oral cholecystography. Two out of 25 cases showed gallstones only following implementation of the radiographic magnification technique. This method seems to be particularly valuable in angiography. In 7 out of 18 abdominal angiograms and 4 out of 14 renal angiograms the number of visible vessel ramifications was greater with the magnification technique. In 5 cases valuable diagnostic information was revealed only by means of the magnification technique. Despite two-fold or 1.7-fold magnification, measurements of skin irradiation exposure showed a reduction of about half in comparison with conventional techniques. Reduced exposure to irradiation combined with improved detail resolution should ensure that this method receives an established place in routine radiodiagnosis.


[Psychosomatic in gynecology and obstetrics--problems and difficulties (author's transl)].

The hypo-, hyper- and normogonadotropic amenorrheas (according to WHO nomenclature) are psychosomatic amenorrheas. The significance of the various psychic factors is pointed out initially. Especially with psychosomatic disorders in gynecology sexual factors play an important role. Adequate treatment of psychosomatic disorders is rendered difficult of the present state of medical education. Lectures in psychosomatics are not presented outside of psychiatry, the dialogue between doctor and patient is almost completely neglected within the medical training. Psychosomatic treatment in the office of patients with state medical insurance poses problems. At our clinic an outpatient department has been open for 2 years. 136 cases have been treated so far. Gynecologist and the psychosomatic specialist examine the patient simultaneously and define a joint treatment plan. Prevailing problems are conflicts with the partner (31%), , conflicts within the family (20%) and conflicts within the social environment (13%). Following adequate diagnostic clarification patients are treated once (19%) or several times (28%) or are referred to other outpatient clinics. A prolonged therapy in our own outpatient department is presently possible in only 2,5% of cases.


[Psychosomatic disorders of the gastrointestinaltract (author's transl)].

The difficulty of the diagnosis of psychosomatic disorders is known to be lying in the shortage of time, the inadequate training of physicians and in the similarity of psychosomatic symptoms are compared to those of solely organic diseases. The irritable stomach-even with hyperacidity--and the irritable colon with constipation or diarrhea are among the most frequent disorders caused by psychosomatic mechanisms. The duodenal ulcer and the ulcerative colitis belong to the true somatopsychic and psychosomatic diseases. Precise organic (diagnostic) clarification and differentiated drug therapy are necessary in addition to psychotherapeutic measures.


[Psychosomatic aspects of cardiac and circulatory disorders (author's transl)].

Psychic stresses may cause cardiac reactions equal to those caused by physical strain. The intensity necessary for the psychic component to cause manifest clinical symptoms depends on the distinctness of the basic somatic cardiac disorder. Representing the group of functional cardiac and circulatory disorders the so-called phobic cardiac neurosis is discussed more in detail as well as the myocardial infarct as representatives of the group of coronary diseases. On the basis of tests (MMPI plus questionnaire) two groups may be differentiated. One group is characterized by pronounced dependance, sparing attitude, avoidance of situations and narrowing of environmental relations, the other by compensatory activity and physical engagement. The distinction is of relevance for therapeutic reasons and for reasons of somatic diagnosis. Among infarct patients we are presently trying to determine single psychic variables with respect to their importance as risk factors. Compulsiveness and rigidity or sociability and extraversion respectively appear to play a role.


The effect of early loss of primary molars on tooth eruption and space conditions. A longitudinal study.

In 186 children study casts were made at the age of 9, 11 and 13 years. The material was grouped according to early loss of primary molars and a comparison was made between children with and without early losses. Early loss was defined as follows: 1. extraction of the first primary molar between 7 1/2 and 9 1/2 years and/or extraction of the second primary molar between 7 1/2 and 10 1/2 years; 2. extraction of the first and/or second primary molar before 7 1/2 years of age. The following variables were studied: space conditions, dental stage for groups of teeth, eruption stage of single teeth. For the incisors the clinical crown length (CCL) was used as a measure of the eruption stage. The results showed that there was a tendency to later eruption and later onset of dental stages in cases without early losses when a comparison was made with investigations where this factor had not been taken into consideration. The second permanent molar erupted earlier in both jaws after early loss of the second primary molar. Children with loss of primary molars before 7 1/2 years developed more crowding than children without losses and losses after 7 1/2 years had little effect on the relative space.


The amino acid composition of Streptococcus mutans and its culture medium supplemented with xylitol.

The amino and keto acid composition of the cells of Streptococcus mutans, strain Ingbritt, maintained and grown on a Trypticase-Phytone based medium without any added carbohydrate or supplemented with xylitol or glucose, was analyzed. The results showed no remarkable differences in the portions of individual amino acids liberated by acid hydrolysis from the cellular proteins of cells grown in the above mentioned media. However, the amount of free amino acids in the water extracts of the cells grown in the glucose medium differed considerably from those obtained from cells grown in the two other media. The amounts of free amino acids of the medium at the end of the growth period were higher in the glucose containing medium than in the two other media. The content of keto acids was lower in the cells grown in the presence of xylitol or without added carbohydrate when compared to those cells grown in glucose containing medium.


Effect of trituration on dimensional changes of dental amalgam.

The dimensional changes of dental amalgams during setting was evaluated using different methods of specimen production, and measurement procedures. Amalgam specimens were prepared from 10 commercially available dental amalgam alloys by mechanical condensation. Dimensional change was measured on microcators with a measuring load of 1 g. The variation in dimensional change with trituration was substantial, and similar to the difference between various brands of alloys at the same trituration time. Porosity seems to vary between 0.1 and 0.6% independent of severity of trituration except for two alloys in which increased trituration time seemed to reduce porosity. It was therefore pointed out that even though trituration in most cases can be altered to make an amalgam expand, such procedures should not be followed since optimal values of other clinically significant properties may not be maintained.


[The mechanism of cell proliferation in acute (immature-cell) leukemia].

In 40 patients with acute leukaemias the 3H-thymidine and mitosis indices were determined in the population of blast cells in bone marrow and the cellularity of bone marrow was determined. The studies were carried out in the first episode of the disease before treatment and in some patients (13) they were repeated during relapse after remission or improvement. The results showed that proliferative activity of blast cells was reduced in relation to precursors of normal granulopoiesis in all forms of acute leukaemia. Myeloblastic leukaemias showed a greater scater of values of both proliferation parameters in relation to lymphoblastic leukaemias. It was found, moreover, that in highly cellular bone marrow the proliferative activity of blast cell population was significantly lower than in patients with low bone marrow cellularity. On the ground of this observation the authors put forward the view that in acute leukaemias the intrinsic mechanism controlling the proliferation of cells is disturbed.


Metallic implants as growth markers in infants with craniofacial anomalies.

The purpose of the study was to test the retention of metallic implants in bone tissue for evaluation of early facial growth patterns in patients with craniofacial malformations. Implants were inserted in 51 patients (age range: 1-17 months) with different diagnoses, the majority of them with various types of cleft lip and/or palate. Seven positions in the maxilla and four in the mandible were employed. Roentgencephalometric follow-up examinations were carried out at various stages up to the age of about three years. The results indicated that the frequency of implants firmly retained within the bone decreased with time depending on the craniofacial deformity and the implant sites. Stability seemed most critical in positions close to the alveolar processes where more than one-half of the implants inserted were dislocated or lost at the three-year follow-up. For the maxillary implants the patients with bilateral cleft lip and palate displayed the highest failure rate. This investigation did not support continuation of the implant method in infants as used in the present study.


Juvenile diabetes mellitus, optic atrophy, hearing loss, diabetes insipidus, atonia of the urinary tract and bladder, and other abnormalities (Wolfram syndrome). A review of 88 cases from the literature with personal observations on 3 new patients.

A review of 88 cases from the literature with personal observations on 3 new patients is given of the syndrome featured by juvenile diabetes mellitus, optic atrophy, hearing loss, diabetes insipidus, atonia of the urinary tract and bladder and other abnormalities. The postmortem in one of our cases is mentioned. The pattern of inheritance is autosomal recessive. The interpretation of the data on diabetes insipidus from the literature and in our three patients is also discussed. It can only be stated that neurohypophyseal diabetes insipidus can be a component of the syndrome and that in many cases--particularly in the presence of lesions of the efferent urinary tract--the possibility of nephrogenous diabetes insipidus can not be excluded with certainty. It seems probable that the same mechanism can be held responsible for the lesions of the olfactory, optic, vestibular and cochlear nerves, the hypophyseal form of diabetes insipidus, retarded sexual maturation, abnormal pupillary reaction, myelopathy and the electro-encephalographic, electroneurological and electromyographic changes in the Wolfram syndrome. The process underlying this affection of neural structures remains obscure.


A new parallel plate dialyser. II. Description of design and in vitro performance.

Using a high efficiency membrane support pattern, described in the previous paper, a prototype of a new parallel plate dialyser has been developed. The new dialyser is designed in such a way that the number of components is reduced to one item per blood layer and the membrane is folded as a continuum. This permits a semiautomatic assembly of the unit, which reduces production costs. Furthermore this technique facilitates aseptic handling of the item. The in vitro performance has been tested and it compares favorably with commercially available disposable parallel plate dialysers.


A new parallel plate dialyser. III. Preliminary experience on clinical performance.

The clinical model of a new parallel plate dialyser with a membrane area of 0.96 m2 with cuprophane 150 PM has been tested in more than 2000 dialyses with good clinical results. The simple design permits an aseptic, semiautomatic assembly and makes cheap industrial production possible. Clinical clearance values for urea, creatinine and uric acid are presented as well as data for ultrafiltration, residual blood volume and rupture frequency. The specific efficiency per square meter has been found to be high.


A new parallel plate dialyser. I. Development and testing of membrane support.

The pattern of membrane support in the dialysate flow path of a dialyser is one of the most important parameters for high utlization of the membrane-area. 27 different injection moulded membrane support patterns were designed to approximate a pattern with the best overall properties. Only 15 of the patterns had acceptable properties in regard to 1) efficiency, 2) compliance, 3) flow resistance, 4) membrane rupture level, and 5) air retention at low flow values. A pattern with parallel interrupted ridges perpendicular to the direction of dialysate flow showed the best overall results although differences were marginal between the best patterns. The chosen support pattern was approximately 35% better in chloride clearance at low dialysate flow, and approximately 200% better at high flows than the conventional Kiil pattern.


Treatment of marked anteroposterior and transverse discrepancies in mandibular prognathism.

A case report of a patient with a severe skeletal Class III malocclusion has been presented. The patient's marked anteroposterior discrepancy was complicated by the fact that his buccolingual occlusion was normal. The solution to this case thus involved a correction of the transverse discrepancy in addition to the anteroposterior discrepancy, which required orthodontic and surgical solutions. A discussion of mandibular prognathism has also been presented.


Biostereometric analysis of surgically corrected abnormal faces.

Biostereometrics is an accurate anthropometric system for quantifying geometric changes of facial form and the relationship of features as they are influenced by growth and by surgery. Facial features distant from the site of surgical intervention are influenced in their geometric relationship to each other by changes in the soft-tissue drape brought about by manipulation of skeletal tissues. The most accurate coordinate system should be elsewhere than on the surface of the face, but if this is not possible it should be in an area farthest removed from the surgical site. This investigation demonstrates that a usable coordinate transformation system can be created by connecting points supernasale and subnasale for establishing the Y Z plane and the construction of the X Z plane at subnasale. Accurate comparative numerical measurements can be made by using soft-tissue landmarks.


Lower incisor extraction in orthodontic treatment.

The extraction of a single mandibular incisor can be employed as a compromise treatment of certain malocclusions, if the end result fulfills the requirements for a healthier dentition which is functionally and esthetically harmonized in relation to the surrounding structures. Indications, contraindications, and the procedure of treatment have been presented. Class I malocclusions with normal maxillary dentition and good buccal interdigitation in which there is severe lower anterior crowding are the best cases for this procedure, provided that the lower anterior arch length deficiency is greater than 4 to 5 mm. and the anterior tooth ratio is more than 83 mm. In conditions exhibiting a deep overbite pattern, reduction of the mandibular anterior unit should be avoided. Furthermore, I do not regard mandibular incisor extraction as a routine orthodontic procedure but, instead, consider it to be an almost last resort measure since it involves the most important stabilizing area of occlusion.


Immediate tonsillectomy for the treatment of peritonsillar abscess.

Our experience with 119 cases of peritonsillar abscess supports the experience of others, that immediate tonsillectomy is a safe treatment which provides prompt, complete drainage of the abscess. There was one episode of immediate postoperative hemorrhage and one of delayed bleeding, but there were no anesthetic complications. If one believes that the abscess is an indication for tonsillectomy and plans to perform the procedure at some time, we recommend that it be performed as the drainage procedure. The total hospitalization time will as a rule be shortened and a second convalescent period avoided. Its major drawback is the inconvenience of inserting a relative emergency into the schedule.


The mandibular dental arch: Part I, lower incisor position.

The position of the lower incisor with respect to hard tissue references has been evaluated. Two samples were used for this purpose: one containing 78 patients with posttreatment records having a postretention period of at least 4 years, and the other composed of 82 normal occlusions. The results indicated: 1) There was no significant difference in relapse of lower incisor crowding between cases where the lower incisor had been moved lingually, labially, or held in the same relative position during treatment. 2) The position of the maxilla should be considered when placing the lower incisor. The APo plane adequately serves as a guide to this purpose, whereas other reference lines such as mandibular plane or facial plane do not. 3) The positions of the incisors with respect to popular cephalometric reference lines such as APo, NB, or mandibular plane were not correlated with the relapse of mandibular crowding. Therefore, other clinical guides might be more successful for determining stability.


The role of dental compensations in the orthodontic treatment of mandibular prognathism.

Thirty-six patients with orthodontically treated mandibular prognathism were recalled for cephalometric and clinical evaluation. A comparison group of 32 non-Class III patients was similarly examined. Analysis of variables associated with the anterior dentition and documentationtion of labial gingival recession and tooth mobility led to the following conclusions concerning the role of dental compensations in the orthodontic treatment of mandibular prognathism. 1. Vertical and horizontal dental compensations were quantitated in the dentition of the study group (pretreatment to postretention). 2. Increased labial gingival recession and increased tooth mobility in functional jaw positions were present in anterior maxillary and mandibular teeth of the study group relative to the comparison group. 3. Proper diagnosis and the establishment of realistic treatment objectives by clinician and patient are necessary to avoid undesirable sequelae and/or undesirable facial esthetics in the treatment of mandibular prognathism.


Primary retroperitoneal extraosseous osteogenic sarcoma: A case report and review of the literature.

A case of retroperitoneal extra-osseous osteogenic sarcoma is reviewed, as well as the criteria necessary for the diagnosis. The general characteristics and the differential diagnosis of the tumor are also presented.


Desire for attention.

Seeking of attention appears to be intimately bound up with certain principles of motivation, especially the seeking of observable results of action and of optimum levels of stimulation, variety and challenge, and the relationship between results and the cost of achieving them--a high cost will tend to inhibit action but enhance the value subsequently placed upon what is achieved. These principles can be applied to personal relationships: thus friendship can be regarded as a situation involving facilitative feedback between persons, hostility as involving inhibitory feedback and lonliness as occurring when there is no feedback. Which of these situations occurs appears to depend upon the relationships between the costs and benefits of interaction between the persons concerned. The care of psychiatric or senile patients in the community appears likely to impose demands for attention which are unreasonably severe ("costly"). Any attempt to change community attitudes in the hope of securing greater acceptance of such demands appears to be unrealistic. Substantial benefits could probably be attained in many cases from training in skills, especially social skills, which would enable patients to cope more effectively with the world as it is.


A scale to measure the cause of life events.

An increase in life event stress has been shown to occur prior to the onset of a number of psychiatric illnesses. This paper describes the construction of a scale to measure the cause of this increased life event experience. One hundred and five normal adults were asked to judge the extent to which any particular event might have occurred by pure chance, by one's own behaviour or by the behaviour of others. These three perceived causative factors are conceptually distinct and together comprehensive. Scalings on these three perceived causative factors for each of 67 life events were derived. The utility of such a scale is discussed.


Evaluation of group processes using visual analogue scales.

Patients in a general hospital psychiatric unit completed Visual Analogue Mood Scales before and after group psychotherapy sessions, and at corresponding times on days without group meetings. Changes in the dispersion of scores between "before" and "after" measurements differed between days with group psychotherapy and days without. Cohesiveness attributable to the group process is suggested as likely explanation for this difference. Factors influencing measurements are investigated and discussed.


A comparative study of long-stay psychiatric patients discharged to boarding houses and satellite houses.

A comparative psychosocial study of two groups of long-stay psychiatric patients discharged from Callan Park Hospital to boarding houses and satellite houses in the Callan Park Hospital region is reported. It was concluded that the social and vocational functioning of both groups was at a low level but that satellite house residents had more spare money and described a less institutionalized and a more homely environment in satellite houses.


The significance of suicide notes.

Studying the contents of suicide notes might help to improve the understanding of individual cases whilst offering an opportunity to search for possible preventive guidelines. In a study in an Australian capital city, suicides for one year (1972-73) were investigated including the medical and psychiatric data where possible, and psychosocial circumstances in each case. The total number of suicides in the year was 135. Twenty-seven individuals left suicide notes of which 25 were available for examination. The mood as reflected in the notes was categorised in terms of depression and hopelessness, neutral affect and hostility. The affect was related to age, sex, marital status and method of suicide. The results are presented with examples of each category and are discussed with respect to their contribution to (i) understanding the cause of death, (ii) understanding the intention of the suicide, (iii) assisting the relatives in coping with the suicide, (iv) drawing attention to those factors where earlier intervention may have averted suicide.


[Fetal hemoglobin in acute leukemias].

The question of fetal hemoglobin synthesis reactivation is a current topic both from the aspect of the genetic regulation of synthesis and from the aspect of the disorder of erythropoiesis in malignant diseases. The author presents the results of the quantitative determination of fetal hemoglobin in 84 children suffering from acute leukemias. The quantitation of HbF was performed by the method of alkalide-naturation and values of hemoglobin A2 by celulose-acetate electrophoresis. In acute lymphoblastic leukaemias fetal hemoglobin has been increased in 59% of the patients and in acute nonlymphoblastic leukaemias in 72% of the patients. The highest values of fetal hemoglobin were about 20%. The author considers that presence of fetal hemoglobin in these diseases cannot be a marker for estimation of remission and aggravation of the disease.


Automatic ventilation during bronchoscopy: experience with a Bird Mark 2 ventilator.

One hundred and fifty patients were ventilated artificially during bronchoscopy using a Bird Mark 2 ventilator with either oxygen or a nitrous oxide in oxygen mixture as the driving gas. Satisfactory conditions for the examination were achieved. There was no significant deterioration in PaO2 or PaCO2.


Assessment of drug sensitivity of human leukaemic myeloblasts. I. Labelling human myeloblasts with 125IUdR for survival studies in mice.

The compound (125)IUdR can be incorporated in a stable form into the DNA of cells. The isotope is released if labelled cells or their progeny die. Consequently the rate of (125)I excretion from mice can be used to follow the fate of labelled cells in vivo. Using these principles we show:(1) Sufficient label can be incorporated in vitro into both fresh and cryopreserved human leukaemic myeloblasts, in non-toxic concentrations, to allow their survival in mice to be estimated by whole-body counting;(2) The release of isotope from labelled cells is sufficiently slow to offer reasonable expectation that this technique can be used for assessing the sensitivity of myeloblasts to cytotoxic agents in vivo (an application described in the second paper in this series, Sonis, Falcão and MacLennon, 1977);(3) The rate of (125)Iexcretion from mice injected with myeloblasts from different donors varies. This probably reflects different rates of spontaneous death of injected myeloblasts;(4) Active rejection of myeloblasts starts within 48 h of their injection into mice;(5) Indirect evidence that phagocytic cells may be active agents in myeloblast destruction in mice;(6) Various methods of immunologically depriving mice were assessed to see if they would result in a useful increase in survival of injected human myeloblasts. We conclude that there is little advantage and some limitations in using mice thus deprived;(7) One of the agents used for immunological deprivation-silica powder-markedly decreased the rate of (125)I loss from mice injected with labelled killed myeloblasts. This experience emphasizes the importance of including the killed-cell control in this assay.


Assessment of drug sensitivity of human leukaemic myeloblasts. II. The toxic effects of cytosine arabinoside on 125IUdR-labelled human leukaemic myeloblasts in mice.

Leukaemia cells from the peripheral blood and bone marrow of patients with acute myeloblastic leukaemia were labelled in vitro with [125I]5-iodo-2'-deoxy-uridine (IUdR). The myeloblasts were then injected into groups of mice and the survival of these cells estimated by measuring isotope loss, using whole-body counting. The isotope excretion from mice treated with various doses of cytosine arabinoside (Ara-C) and those not treated with drugs were compared. This comparison showed that the sensitivity of myeloblasts to the drug varies from patient to patient, and in one case was different for myeloblasts from bone marrow and from blood from the same patient. We compare the clinical responses of myeloblasts to Ara-C in 6 patients, who had high peripheral blood myeloblast counts, with the sensitivities of their myeloblasts to Ara-C in mice. This comparison indicates that the assay might be a useful way of predicting the response of leukaemic cells in patients to cytotoxic agents.


Bronchiectasis in acute leukaemia.

Five children in remission from acute lymphoblastic leukaemia developed bronchiectasis when on chemotherapy. Persistent collapse or consolidation on chest radiographs was helpful in suggesting the diagnosis. Necropsy established the diagnosis in one child who died of massive haemoptysis when in complete remission, and bronchography confirmed the diagnosis in three. In a further child the diagnosis was based on clinical and chest X-ray findings alone. The surviving children were treated with prophylactic rotating antibiotics. Routine chest radiographs are recommended in children with acute lymphoblastic leukaemia, as bronchiectasis may otherwise be underdiagnosed.


[Hardening of photopolymerizable sealing materials in variously deep enamel zones (in vitro)].

The effect of irradiation times of various lengths on the resulting Vickers-hardness and polymerisation of adhesives (Estilux glaze, Nuva Seal) was estimated for varying UV light sources. Secondary effects depending on position were found in the polymerisation, the progress of which could be estimated. The results of the polymerisation experiments, irradiating caries-containing and healthy enamel sections, using appropriate UV light sources, show polymerisation of adhesives with definable Vickers-hardness in enamel zones of various depths.


[Caries prevention by means of a Na2FPO3-toothpaste after 7 year's application].

After 7 years unsupervised use of a Na2FPO3 paste the number of new DMF-surfaces was 36 to 38% lower than in the control group. The caries-inhibiting effect is statistically significant (P less than 0.001). Separate consideration of the first molar reduced caries of the other teeth to 40--42%.


[Studies on silicate-containing and silicate-free adhesives compared to composite materials II].

The photo-polymerisable adhesive Estilux glaze and its successor product Estiglaze microfill as well as a compound from the same firm were subjected to comparative investigations. Maximal polymerisable thickness of the named materials were ascertained by means of variable intensive light sources. Electron-microscopic investigations were carried out on the matrices in order to estimate the wetting behaviour. No generally valid connection between hardness and abrasion of comparative materials could be observed, but Estiglaze microfill, containing filling-substance shows reduced abrasiveness to the factor 2.5 in comparison to products free from filling substance.


[Testing of various methods for the determination of processing time for amalgam].

Four different test methods for the determination of the processing time of freshly mixed amalgam pastes were examined with the view to their utility, using 9 commercial powder alloys of different setting speeds. The tests used were a schematised stuffing test, close to the procedure used in practise, the cutting test and the compressive strength test after 10 minutes, both of which are still quoted as alternatives in the provisional standard DIN 13904, as well as a Hg addition test described by Jørgensen. The compressive strength test proved to be the quickest and most accurate. It is therefore best suited for routine examinations and general control and is recommended for inclusion in the DIN. It is necessary to set up calibration curves with the help of the stuffing test in order to estimate the processing time. These have to be separately estimated for filing amalgam and globular amalgam. The cutting test proved to be relatively inaccurate. The Hg addition test, though giving usable values, consumed too much time and material.


[The sensitivity of various in-vitro-test systems in biological testing of materials].

In the present paper the biological activity of methylmethacrylate Monomer and di-methylparatoluidin on stationary, cell-proliferating and bacterial cultures is examined. The equi-toxic concentrations were lower in cell culture systems than in stationary cell suspensions or bacterial cultures. Accordingly biological reaction appears to depend on the effective concentration of the toxic substance as well as on the specific sensitivity of the test system. There is no correlation between the sensitivity of cellular and of bacterial test systems.


[Determination of surface morphological changes during therapy of gingivitis].

Changes in inflammatory gingival disease of the anterior dental area of the mandible caused by therapy are evaluated with the help of surface morphometric methods. The clinical diversities of the healthy and diseased gum can be presented by comparative consideration of the measurements. The relationship of the contour of the gum to tartar formation and capacity for retention of plaque are interpreted. The ratio of papillary to dental surface allows these findings to be incorporated into the physiomorphological or pathomorphological state.


[Extracellular polysaccharides from Streptococcus mutans of various biotypes--chemical characterization and enzymatic hydrolysis].

The composition and proportions of different types of compound were established in extracellular polysaccharides synthesized in virto by streptococcus mutans strains of various biotypes. The polysaccharides were further enzymatically hydrolysed with dextranase and the degree of hydrolysis as well as the character and amount of the products of decomposition were determined. Under the conditions employed the strains synthesized solely glucanes. The water insoluble polysaccharides of strains of various biotypes show significant differences with regard to the proportions of alpha 1,3 and alpha 1,3,6-compounds. There is a significant correlation between the proportions of these compounds and the degree of hydrolysis by dextranase.


[The forameter, a device for the exact measurement of the root canal length].

The forameter is an instrument used for measuring the length of the root canal. Here the use of the principle of resistance measurement is refined. The position of the apical foramen is shown acoustically as well as visually. This investigation gives positive results for the measurements in the treatment of devitalised teeth. The inaccuracy of measurement in living teeth appears too great.


Neuropathy in a patient with McArdle's syndrome and diabetes mellitus.

A juvenile-type diabetic patient of five years standing presented with a mononeuritis and gave a history of painful muscle swelling induced by exertion. Failure of the blood lactate to rise during ischaemic exercise and a normal blood glucose rise following intravenous glucagon confirmed the clinical diagnosis of muscle glycogenosis. The association of diabetes and McArdle's Syndrome has not previously been documented. An ulnar nerve palsy, which persisted for many months, followed the ischaemic exercise test possibly due to compression by muscular swelling, but may have been exacerbated by the co-existing diabetes.


Endodontic therapy of traumatised teeth in children.

One of the most difficult problems met with in endodontic therapy for children is the traumatized anterior tooth whose root is still incomplete. In cases where the pulp is vital, treatment by pulp capping or pulpotomy is directed to preserving the vitality of the radicular pulp to ensure completion of root formation. Calcium hydroxide remains the material of choice in both forms of treatment. Once root formation is complete, removal of the pulp residue and filling of the root canal may be performed as a preliminary to restoration by means of a post retained crown. Where the pulp is non vital, attempts to fill the funnel shaped apical part of the canal, whether from a coronal approach or by open operation for retrograde filling, have proved unsatisfactory. Many workers have shown however that a number of root filling materials and root dressings are capable of inducing either continued root growth or a closure of the apical region by a calcific scar. A detailed survey of 34 teeth treated by this method has been made and the important principles which appear to influence the success of the technique are enumerated.


The world wide distribution and significance of oral diseases.

Data available to WHO shows that the profile of oral diseases differs dramatically between the technically advanced and the developing countries. In technically advanced countries the high tooth mortality due to caries is decreasing as a result of widespread dental care, though the incidence of the disease is little affected. Unless preventive measures can be applied the cost of maintaining curative services will outstrip the financial resources of even the most prosperous countries. In the developing countries where manpower is scarce the traditionally low prevalence of caries is tending to increase with progressive urbanization. Preventive measures are therefore vitally important and there is urgent need for field testing in these conditions. In both cases the development of preventive measures against periodontal disease is essential if teeth saved from loss by caries are not to be lost in later decades from the ravages of periodontal breakdown.


The clinical trial in multidisciplinary research.

Dental research has developed along two separate paths. Epidemiological studies can only indicate a cause-disease relationship while laboratory experiments can only be applied to the human situation as a working hypothesis. The final solution can only be arrived at by setting up controlled studies in man, though there are limitations on the possibility of control of some variables in human studies. Experimental studies on the formation of pellicles and plaque are described as examples of the use of clinical trials to bridge the gap between basic research and epidemiological data. The ideal model for dental research would involve the identification of a clinical problem and its subdivision into small biological units which could be studied in the laboratory in order to develop working hypothesis. An in vivo model would then be devised to test the hypotheses and finally they would be applied in a well controlled trial.


Cultural factors in clinical pain assessment.

Experimental evidence suggests that the threshold at which a given stimulus is perceived as painful is relatively constant both for an individual and between individuals. However, higher thresholds at which pain described as severe or at which particular behavioural response occurs are much more variable and appear to depend on cultural factors. Since one concern of a healing profession is to alleviate or minimize pain it would be helpful if some means of assessment of the intensity of pain experienced by other persons were available. Unfortunately no such measure exists. Distinction must be made between relief of pain which should be based on physiological principles and relief of distress in which socio-psychological factors are of much greater importance.


International collaboration and research in the organization of the education of dentists and the public.

The dental curriculum in Western countries is still heavily biased towards technical competence in restorative procedures. Despite the evidence from many countries that curative dentistry has failed to make a significant impact on dental health, there is a reluctance to change to a preventive emphasis. Unfortunately dental education in developing countries is being modelled on the same pattern even though this is totally irrelevant to local needs and resources. The greatest need is for health  education designed to influence the lifestyle of people in a way which will reduce the prevalence of dental disease. Unfortunately the dentist's present training does not fit him to play an effective part in such a programme.


The epidemiology of oral tumours. A report prepared by a Working Group of the Commission on Classification and Statistics for Oral Conditions.

The vital statistics collected by the national and international registries and organizations include information on oral cancer. As their work proceeds and the accumulated information increases and probably also becomes progressively more reliable because of increasing accuracy in clinical diagnosis and death certification, the purpose of epidemiological research, that is, the identification of etiological factors, will come nearer to fulfilment. On the other hand, very little is known about the epidemiology and demography odontogenic tumours. Although these tumours are relatively uncommon they are of considerable practical and theoretical importance to dentists, oral surgeons and pathologists. Since workers in the oral field are especially concerned with these lesions they are in a particularly favourable situation to collate data. Although a lengthy period would be required to amass significant numbers of cases, the effect would be well worth while.


Juxtacortical chondrosarcoma.

The features are described of seven cases of "juxtacortical" chondrosarcoma, the term introduced by Jaffe for a rare but distinct entity and now accepted in the World Health Organisation classification as preferable to the term "periosteal" chondrosarcoma. In all cases the lesion involved the shaft of a long bone, most often the femur, and in two cases two different long bones were affected. Six of the seven patients were male and all were in the second decade. The characteristic appearance was that of a small tumour adjacent to the cortex with areas of spotty calcification often accompanied by radiating bone spicules perpendicular to the bone shaft and a typical Codman's triangle. Histologically all the tumours showed a cartilaginous lobular pattern, well limited on the surface and seldom infiltrating the cortex; areas of spotty calcification and enchondral ossification were often present but tumour osteoid and bone were conspicuously absent. Despite the ominous histological aspect, the prognosis proved to be relatively favourable compared with the usual central chondrosarcoma of a similar grade of malignancy.


Production of mouse globin in heterokaryons of mouse erythroleukaemia cells and human fibroblasts.

In an effort to activate the globin genes of non-erythroid cells, tetraploid murine erythroleukaemia cells (Friend cells) were fused with diploid human amniotic fibroblasts. When the Friend cells were pretreated with dimethylsulphoxide, an average of 27% heterokaryons was observed. These cells stained with benzidine, an indication that they contained haemoglobin. The cells incorporated radioactive amino acids into proteins. Electrophoresis of [3H]leucine-labelled lysates on SDS urea polyacrylamide gels indicated that up to 7% of the newly synthesized protein co-electrophoresed with globin. CM cellulose chromatography demonstrated the presence of mouse but not human globin chains. Hybridization analyses of cytoplasmic RNA also revealed only mouse globin mRNA in the heterokaryons. Although heterokaryons form readily between mouse erythroleukaemia cells and human fibroblasts, and globin synthesis does occur, only the erythroid partner in the fusion system employed here directs globin production.


Independent dimensions of depression: a factor analysis of three self-report depression measures.

Covariance studies of objective depression measures have concentrated on total scores. This approach is relatively insensitive in specifying whether these instruments measure the same sub-aspects of depression. To investigate this question, a factor analysis was performed on the items of the Beck Depression Inventory and the Zung Self-Rating Depression Scale and lists A, B, C, and D of the Lubin Depression Adjective Check Lists. Ss were 91 college students and 29 correctional institution inmates. Four clearly interpretable multimeasure factors resulted from a Varimax rotation. The most salient factor was labeled "Depression: Affective Malaise." Earlier studies also have shown this to be a dominant and reliable dimension of depression. The other factors were: Suicidal Ambivalence," "Appetite-Weight Loss," and "Fatigability." Females showed greater Fatigability associated with depression. Factors specific to the Beck and Zung measures also were found, which suggests that the different emphases of these instruments, intensity/severity vs. frequency of symptoms, may contribute very specific depression indicators. This may indicate that both intensity and frequency of symptoms ought to be considered to obtain a "best" objective measure of depression.


Animal studies concerning the cariogenicity of dry breakfast cereals.

Four studies were performed in rats and hamsters concerning the cariogenicity of cereals and the role of sucrose in that process. The findings indicate that sucrose content per se does not necessarily reflect the cariogenic potential. Presweetened cereals were more conducive to the formation of smooth surface caries in the hamster than were nonpresweetened cereals while no major differences between the cereals were observed in occlusal caries in rats.


Collaborative evaluation of a rat caries model in six laboratories.

When highly controlled parallel rat caries studies were run simultaneously in six laboratories, a similar pattern of caries developed in every laboratory with a range in mean values such that the results of no investigator were significantly different from those of at least two others. These results indicate that the major factors influencing development of rat caries have been recognized and can be controlled within reasonable limits.


A chromatographic study of the relative affinities of rat bone and skin collagen alpha1 chains for hydroxyapatite.

The affinity of a bone collagen alpha1 chain for hydroxyapatite has been compared to a similarly isolated skin component from the same animals. The chain from bone exhibits a higher affinity for the mineral. This enhanced affinity appears to be related to its primary structure, specifically its hydroxylysine moieties.


Evaluation of oral submucosal blood flow at dental injection sites by radioactive Xenon clearance in beagle dogs.

Oral submucosal blood flow was measured at dental injection sites in anesthetized dogs and compared with subcutaneous blood flow. Blood flow was calculated from the measured half-time for clearance of radioactive xenon dissolved in saline. By this method, oral submucosal blood flow was much greater than subcutaneous blood flow and was comparable in magnitude to values reported for cerebral blood flow. Injection of a solution containing 1:100,000 epinephrine at the mandibular canal produce a delayed clearance of isotope which was three times as long as the clearance time for solutions without epinephrine.


Investigations into black extrinsic tooth stain.

An investigation has been carried out into the nature of the black pigment in black extrinsic tooth stain. The results suggest that the black material is a ferric salt, probably ferric sulfide, formed by the reaction between hydrogen sulfide produced by bacterial action and iron in the saliva or gingival exudate.


Estimation of mesiodistal width of permanent canines and premolars in early mixed dentition.

The accuracy for predicting mesiodistal widths of unerupted permanent canines and premolars from x-rays and their estimations based on the already erupted permanent teeth were tested in a group of Israeli children. The observed posteruptive widths related more closely to predicted values obtained from x-ray measurements than from tabulated estimations.


In situ replication techniques: I. Preliminary screening and the negative replication technique.

Fourteen commercially available elastomeric materials were investigated for their suitability as in vivo replication media. After a preliminary screening on an annotated specimen, three materials were chosen for further study. Of all materials evaluated, Xantopren Blue and Silene silicone impression materials provided the best results in vivo. This study demonstrates that a high resolution (ca 1 micron) negative replication technique may prove useful for the clinical evaluation of single-surface phenomena.


Loading rate and temperature as variables in amalgam bending.

Three commercial dental amalgams of known dissimilar clinical properties were evaluated in pure blending at widely different loading rates and temperatures. Comparative data of fracture stress at 140 F rank these alloys according to their clinical fracture resistance; the phenomenon of creep may account for early marginal fracture prior to corrosion-induced fracture.


Hormonal responses of bone in a continuous flow cultural system.

Calvaria from five-day-old mice incubated in a continuous flow system (10 calvaria per culture chamber with 1 ml volume; flow rate 1ml/hr.). In 24-hour cultures, calvaria showed less resorption than in stationary culture. Short-term responses to PTH and calcitonin were similar to those observed in vivo.


The electron microscopy of bacteriophage-like particles in dental plaque.

The morphology of bacteriophage-like particles contained in samples of dental plaque is described. The phage-like particles were observed within fusiform-shaped bacteria and in clumps between bacteria. The particles were hexagonal in cross section, approximately 1,100 nm in diameter and contained an electron-dense core. In areas of cell lysis tail forms were observed both free and in association with the particles. Occasional particles were attached to bacterial cell walls by means of shortened tailpieces.


A microbiological study of normal flora of macropod dental plaque.

The percentage bacterial composition of dental plaques from 12 macropods was determined. The major group of organisms was gram-positive filamentous and pleomorphic rods whose median representation was 92.2%. These were mainly Actinomyces viscosus (median value 62.5%) and Bacterionema matruchotii (median value 23.2%). Streptococci were poorly represented (median value 4.2%) as were anaerobic gram-negative organisms. Aerobic gram-negative bacteria were identified as neisseriae and Moraxella sp. The macropod plaque flora was compared with that of human beings and rodents and the differences discussed in relation to dietary differences and the early externalization of the marsupial young.


Analysis of Asgar-Mahler reaction zone in Dispersalloy amalgam by electron diffraction.

Selected area reflection electron diffraction has been used to determine the phases present in the reaction zones surrounding the Ag-Cu eutectic dispersant in Dispersalloy amalgam. The experiments were carried out on two kinds of specimens, (1) Dispersalloy amalgam and (2) Dispersalloy amalgam using 30, 50, 75, and 100% more mercury than found in commercially available capsules. The results show that the reaction zones in the specimens of the present investigation consist of Cu6Sn5 and Ag2Hg3. These diffraction data confirm the presence of the phases in the reaction zone which are suggested by the elemental analysis obtained by Mahler and his associates using an electron probe. Moreover, the strong intensity of the eta-Cu6Sn5 diffraction rings suggests a composition which is predominantly Cu6Sn5, again, in agreement with the electron probe data.


Effects of daily rinses using sodium fluoride and organic fluorides on rat caries.

The organic fluorides, alexidine dihydrofluoride and amine fluoride, provided greater protection against caries than sodium fluoride when used as a daily mouthrinse in rats. Alexidine dihydrochloride also provided significant caries restriction.


The effect of added particles on the properties of Ag3 Sn-additive amalgams.

Physical and chemical properties of amalgam alloys containing varying amounts of copper were evaluated. Evidence presented refutes the theory of physical strengthening due to the addition of silver-copper by its eutectic. Results suggest that reactive copper could be more advantageously added to the system by using fewer copper additive particles; these particles may need to have a greater copper content that those used in Dispersalloy.


Computerized prediction of optical density for diagnostic radiology.

A computer program was formulated and verified experimentally to predict the optical density on an image receptor for any given set of radiographic variables including tube kilovoltage, milliamperage, and wave form; x-ray beam filtration; nature of filters and absorbers, and type of x-ray film.


Levan production by a strain of Rothia: activation of complement resulting in cytotoxicity for human gingival cells.

An extracellular polysaccharide identified as a levan has been isolated from Rothia dentocariosa, strain 477 serotype 2. The levan produced by strain 477 has been found to activate the complement cascade in the absence of specific antibodies. This activation was found to be cytotoxic for human gingival cells in tissue culture.


In vitro enamel demineralization by Streptococcus mutans in the presence of salivary pellicles.

Salivary pellicles developed on extracted teeth favorably affected the degree and nature of enamel demineralization when the teeth were incubated in vitro with either of two pure strains of cariogenic Streptococcus mutans. The mechanism responsible for this protection may relate to the permselective properties of these salivary pellicles.


Root surface caries in the molar teeth of rice rats. II. Quantitation of lesions induced by high sucrose diet.

Weanling rice rats were fed either standard laboratory chow or Diet 2000. The animals were sacrificed at 4, 8, 12, and 15 weeks. There was an increasing amount of exposed root surface and root surface caries with age in the animals fed Diet 2000. There was exposed root surface but no caries in the animals fed laboratory chow.


Phagocytosis of latex beads by a human gingival epithelial-like cell line in tissue culture.

Phatocytosis by a human gingival epithelial-like cell line in tissue culture was studied using latex beads as a marker. Electron microscopic and chemical analyses revealed that the cells ingested the beads in a quantitative and reproducible manner. This phagocytosis system is potentially useful for studying the effects of dental plaque on cell metabolism.


Polyacrylamide gel electrophoresis of human salivary histidine-rich-polypeptides.

A method of polyacrylamide gel electrophoresis for examining histidine-rich-polypeptides in human saliva is described. Comparison is made to several commonly used electrophoretic techniques. The described method allows for the resolution of seven histidine-rich-polypeptide fractions and is convenient and quite reproducible.


Comparing personality traits of male and female dental students: a study of two freshman classes.

The marked increase in women enrolled in dental school warrants a reassessment of dental student personality profiles. The purpose of this study was threefold: (1) to compare personality profiles of two first-year dental classes, (2) to compare male and female dental student profiles to their respective norm populations, and (3) to compare male and female dental student personality traits with each other. The Comrey Personality Scales were administered to two first-year dental classes at the University of California at Los Angeles. Between sex and within sex comparisons were made over ten inventory scales. Results indicated that the collective personality profiles of male and female dental students were markedly similar to each other for both classes. These results do not reflect the differences encountered between the sexes in the norm population. It was also noted that the "average" male dental student differed from the male norms on Orderliness versus Lack of Compulsion, Social Conformity versus Rebelliousness, and Emotional Stability versus Neuroticism. In addition, "average" female dental student differed from the female norms on Masculinity versus Femininity.


Experiences with a training course in patient counseling.

A program in patient counseling for dental students is described. The main objective of the present course is to make the students more aware of their own behavior and to train them in patient-centered behavior. In an effort to evaluate the effects of the training, a pilot evaluation study was completed. Students who had completed training two weeks before the study showed more nondirectiveness, empathy, warmth, and acceptance than students without such training. Seven months after the training a learning effect was evident as well.


Communication skills training for dental students.

It is important to teach future health professionals about human interaction, a process that will underlie their technical procedures throughout their careers. In the past there have been problems with student acceptance of such teaching. This paper reports a promising attempt to increase the perceived relevance and credibility of a course in communication skills for dental students. Two important features of this course are (1) the use of video-taped communication vignettes, derived from actual dental office situations, to increase the perceived relevance of the program for the dental student and (2) the use of selected clinical dental faculty members as group facilitators to increase the credibility of the program.


Immunity to attenuated influenza virus WRL 105 infection induced by heterologous, inactivated influenza A virus vaccines.

Groups of student volunteers were immunized with one of five different inactivated influenza virus vaccines. The concentration of virus in the various vaccines differed by both the international unitage test and by the concentration of haemagglutinin, as measured by the single radial diffusion test; the results of the two methods of standardization showed no correlation. The serum HI response to immunization was variable; volunteers given A/England/72 showed a 16.6-fold increase in homologous serum antibody titre whilst volunteers given A/Hong Kong/68 vaccine showed a 4.2-fold increase. The variable response of volunteers to immunization could not be explained by the varied concentration of virus in the vaccines, as measured by either test, the titres of serum HI antibody present before immunization, or a combination of these two factors.The ability to infect volunteers with WRL 105 virus 4 weeks after immunization with heterologous, inactivated virus vaccine was directly related to the degree of cross-reactivity between the haemagglutinins of this vaccine virus and WRL 105 virus. Thus, the greatest number of infections by the challenge virus were seen in volunteers given A/Hong Kong/68 vaccine, less were observed in volunteers given A/England/72 vaccine, and least were found in groups given A/Port Chalmers/73 or A/Scotland/74 vaccine. However, compared with the incidence of infection in volunteers given B/Hong Kong/73 vaccine, all the heterologous influenza A vaccine gave some immunity to challenge infection.


Isolation of Campylobacter fetus from recent cases of human vibriosis.

Campylobacter fetus was isolated from five recent cases of human vibriosis, of which two were adults and three were children. One adult presented with pericarditis and the other with recurrent pyrexia. Campylobacter fetus subsp. intestinalis which resembled cattle strains serologically, was isolated under CO2 or anaerobic conditions from blood cultures of these patients. Two of the three children had kwashiorkor and the third was only 8 days old. Isolates identified as Campylobacter fetus subsp. jejuni were cultured from blood of these patients, two of whom had diarrhoea. Three patients succumbed, despite adequate antibiotic therapy. The epidemiology of the disease is discussed and it is suggested that infection may have been from the patients' own flora.


Myxomatosis: the transmission of a highly virulent strain of myxoma virus by the European rabbit flea Sphilopsyllus cuniculi (Dale) in the Mallee region of Victoria.

The European rabbit flea Spilopsyllus cuniculi (Daley was introduced into Australia to act as a vector of myxoma virus. It was first released in the semi-arid Mallee region of Victoria in 1970 where epizootics cuased by field strains of myxoma virus occur each summer. Introductions of the readily identified Lausanne strain were made annually following the release of the flea. The introductions were successful and the strain persisted for up to 16 weeks despite competition from field strains. The Lausanne strain is more readily spread by fleas than the Glenfield strain which has been widely used in rabbit control. The ability of the Lausanne strain to persist and its effective transmission compared with the Glenfield strain may be due in part to the more florid symptoms of the disease.


Innate resistance to myxomatosis in wild rabbits in England.

Wild rabbits (Oryctolagus cuniculus) from one study area in England have been used over a period of 11 years to investigate the possible appearance of innate resistance to myxomatosis. Rabbits of 4-6 weeks old were captured alive, retained in the laboratory until at least 4 months old, and then infected with a type of myxoma virus which kills 90-95% of laboratory rabbits. Observations were made of symptoms, mortality rate and survival times.In the first 4 years of the study (1966-9), mortality rates were not significantly different from those of laboratory rabbits, although survival times of wild rabbits were appreciably longer. In 1970, the mortality rate amongst wild rabbits was 59%, in 1974 it was 17%, and in 1976 it was 20%, thus showing that a considerable degree of inherited resistance to myxomatosis has developed.The types of myxoma virus most commonly isolated from wild rabbits in Great Britain in recent years have been those which cause 70-95% mortality in laboratory rabbits. Therefore, if the degree of innate resistance demonstrated is widespread in Great Britain, there are serious implications regarding the size of the rabbit population, because myxomatosis has been an important factor in holding rabbit numbers at a relatively low level.


The potential for contamination of intravenous infusions by airborne skin scales.

Skin scales may be attracted onto the surface of administration set connector needles before insertion into infusion containers. Viable microorganisms associated with skin scales may therefore gain access to the infusion by this route. A technique is described for creating an environment of airborne skin scales. This environment is used to examine the attraction of skin scales onto the surface of administration set connector needles and three other materials. After exposure, skin scales are found adhering to the surface of each material examined. The attraction of skin scales onto administration set connector needles is dependent on the time of exposure to the environment. Results suggest that intravenous infusions can be contaminated by this route when the infusion and administration set is assembled.


A standard technique for the isolation of Salmonella from animal feeds.

Two trials were carried out by 9 and 47 laboratories to evaluate the reproducibility and sensitivity of a standard technique for the isolation of salmonellas from animal feeding stuffs. The trials involved the examinations of test samples containing known numbers of salmonellas by a buffered peptone water pre-enrichment technique. Statistical analysis of the results of the trials showed that the method was capable of detecting salmonellas in most probable numbers as low as 2.3 per 100 g and that no significant differences in performance were observed between laboratories. The standard technique described is recommended for the examination of animal feed and conforms to international recommendations.


Changes of heart rate during administration of local anesthetics in the oral region.

In an attempt to clarify the mechanism of shock in dental patients, the effects on the heart rate of the injection of an anesthetic agent into the oral mucosa were studied. The heart rates of the subjects decreased by an average of 12.6% during infiltration anesthesia, which was greater than that induced by the mandibular block or breathholding. The response was completely blocked by general anesthesia and partially blocked by inhalation of nitrous oxide and oxygen or previous administration of atropine, indicating the possible participation of trigeminal-vagal reflex in producing these changes of heart rate.


Computer-based analysis of 227 white males and females to establish range of malar-maxillary cephalometric relationships.

A computer-based analysis was undertaken on 227 white males and females to establish the relationship of the sella-nasion orbitale angle to that of the sella-nasion A point. The ratio of sella-orbitale to sella-nasion was also studied and it was discovered that these results were significantly related to the sella-nasion A-point angle. There was little sexual dimorphism. These results provide objective guidelines to the surgical treatment of people suffering from hypoplastic development of the middle part of the face.


Comparison of ilium to rib for bone grafting in defects of canine mandibular alveolar fidge.

The behavior of iliac and rib grafts in surgically created defects in canine alveolar ridges was investigated. Despite the greater amount of potentially osteogenic tissue in the iliac graft, no significant qualitative differences were noted in the bony remodeling for a year. However, the rib grafts did form a mature superior cortical border significantly more rapidly, leading to speculation on the advantages of rib over iliac graft in alveolar ridge grafting.


The spinocervical tract as a possible pathway for muscular nociception.

In decerebrate and chloralose-anaesthetized spinal cats, micro-electrode recordings were made from axons of the spinocervical tract (SCT) during intra-arterial injection of bradykinin, 5-hydroxytryptamine and potassium into the gastrocnemius-soleus (GS) muscle. The results suggest that muscular group IV and group III afferent units which respond to the above painful stimulation project into the SCT. The portion of SCT units that could be activated by injections of these algesic substances into the GS-muscle was different in spinal and decerebrate preparations, showing that the SCT neurones are subject to a descending influence. It is concluded that the spinocervical tract, in addition to its function as a cutaneous sensory pathway, may serve as a pathway for muscular nociception in the cat.


Acute myelogenous leukemia as a late complication of the multimodality therapy for Hodgkin's disease.

Progressive thrombocytopenia developed in a patient following the completion of total lymphoid irradiation and combination chemotherapy for Hodgkin's disease. Thorough evaluation eventually yielded a diagnosis of acute myelogenous leukemia (AML). Previous workers have suggested that the development of thrombocytopenia with a hypoplastic marrow following total lymphoid irradiation indicated recurrent Hodgkin's disease. When the combination cytopenias and hypoplastic marrow is recognized these workers have recommended early combination chemotherapy. Recent data suggest a 1300-fold increase in the risk of AML following multimodality therapy for Hodgkin's disease. We feel that a careful search for AML should be conducted in patients with deteriorating  hematologic parameters following therapy for Hodgkin's disease and that this search should include sampling bone marrow outside irradiated areas.


Chemotherapy with cyclophosphamide, vincristine, cytosine arabinoside, and prednisone (COAP) in childhood acute lymphoblastic leukemia (ALL).

Three groups of children with acute lymphoblastic leukemia (ALL) were treated with intermittent cyclophosphamide, vincristine, cytosine arabinoside, and prednisone (COAP). Group A (no prior relapse) and Group B (prior single-agent relapse) received COAP after 12 months on another chemotherapy regimen. Children in Group C (prior relapse on multiagent regimens) received COAP following A-COAP (asparaginase plus COAP) reinduction. Median disease-free survival after beginning COAP was not reached for Group A, but was only 7 months for Groups B and C. As of November 1976, there were 8 of 15 Group A patients, 1 of 12 Group B patients, and 1 of 28 Group C patients who had remained disease-free from 38 to 60 (median 54.5) months and were off chemotherapy. COAP has activity in childhood ALL. However, effectiveness is markedly diminished in patients with prior bone marrow relapse.


Lack of correlation between blast cell size and length of first remission in acute lymphocytic leukemia in childhood.

The bone marrow from 55 children with acute lymphocytic leukemia diagnosed from April 1969 to June 1973 were evaluated for blast cell morphology and size. Sixteen marrows contained a predominance of macrolymphoblasts (greater than 12 mu), while the remainder contained mainly microlymphoblasts. There was no correlation between blast cell size and the known front-end prognostic indicators of age and initial white blood count, nor could blast cell size be used to predict the length of initial bone marrow remission.


Experimental chemotherapy of rat leukemia RBA-Le with cis-diamminedichloroplatinum.

The antileukemic activity of cis-diamminedichloroplatinum (PDD) was studied in rats bearing myelogenous leukemia RBA-Le. Clinical picture, changes in life-span, hematological indices and weight changes were used to assess the effectiveness of the therapy. Maximum effectiveness was noted when PDD was given in combination with Methotrexate (MTX) and Poly I:C, respectively. The mean life-span of the rats treated with PDD and MTX was prolonged to 37 days that is an increase of 147 percent of the control level. Furthermore 20 percent of the treated animals survived symptom-free for more than 60 days. Out of 20 animals receiving PDD in combination with Poly I:C 6 rats survived 60 days symptom-free. In remaining 14 animals who finally died on leukemia an 85 percent increase in life-span was noted. Only slight increase in life-span was recorded in those groups treated with PDD alone and in combination with Cyclophosphamide regardless of dosage schedule. The general toxicity of PDD therapy is discussed.


[Health personnel and dental health. Visits to the dentist and attitudes to dental care in a group of health personnel].

Studies among Norwegian institutionalized persons have shown an extensive unmet need for dental treatment and a potential demand for preventive dentistry among young and middle-aged institutionalized personnel. The purpose of the present study was to gain information concerning the dental habits of the health personnel working in an institution, since there is reason to believe that the attitudes and dental habits of the employees will be of importance by the introduction of preventive dental health programs. A questionnaire was sent to 454 employees at Lier Sykehus, a mental hospital near Oslo. 385 persons answered the questionnaire (response rate 85). 82% of the respondents visited a dentist regularly, most of them twice a year. Many showed interest in getting treatment at the hospital's dental clinic. It is reasonable to suggest that the dental service at hospitals also should include the health personnel. In that case, the employees should pay the usual fees of the Norwegian Public Dental Health System. In conclusion, good dental care habits of the hospital employees will presumably affect dental health behavior of the handicapped, and thus make our goal--a better dental health for institutionalized persons--easier to achieve.


Further study of the effect of enzyme-enzyme interactions on steady-state enzyme kinetics.

This paper continues an earlier one [Hill, T.L. (1977) Proc. Natl . Acad. Sci. USA 74, 3632-3632] and presents further introductory examples. Most attention is devoted to a closed linear chain of two-state enzyme molecules with nearest-neighbor interactions. The one-dimensional Ising theory can be used here. The Bragg-Williams (mean field) approximation is introduced to deal with a one-, two-, or three-dimensional lattice of enzyme molecules, at steady state, with an arbitrary kinetic diagram. The behavior of the flux in a phase transition is noted. Finally, a treatment is given for the first effect (second "viral" coefficient) of interactions on the flux in a dilute solution of two-state enzyme molecules.


Local interactions in bends of proteins.

Calculated probabilities of bend formation in 47 amino acid sequences of N-acetyl-N'-methylamide dipeptides, determined from a statistical mechanical analysis using empirical conformational energies, were compared with the observed fraction of bends formed in the same 47 dipeptide sequences in the x-ray structures of 20 globular proteins. Agreement between the calculated and observed fraction of bends was found for 26 dipeptides, suggesting that, for those particular dipeptide sequences, local interactions dominate over long-range interactions in determining conformational preference. Seven dipeptide sequences, all of which contained a Gly residue, had a significantly higher calculated than observed bend preference, indicating the strong influence of long-range and/or solvent interactions in those sequences. Of the 14 sequences for which the calculated was significantly less than the observed bend fraction, 13 dipeptide sequences contained at least one polar residue (Ser, Asn, or Asp) and/or an aromatic residue (Phe or Tyr), suggesting that solvent effects may play an important role in dictating the conformation in these sequences. The analysis of dipeptide sequences in the twenty globular proteins also indicated that the 4 leads to 1 hydrogen bond is not a dominant factor in stabilizing bends in proteins, and that most dipeptide sequences are capable of forming several types of bend conformations.


Structure of proteins: packing of alpha-helices and pleated sheets.

Simple models are presented that describe the rules for almost all the packing that occurs between and among alpha-helices and pleated sheets. These packing rules, together with the primary and secondary structures, are the major determinants of the three-dimensional structure of proteins.


Thermodynamic aspects of the linkage between binding of chloride and oxygen to human hemoglobin.

Oxygen isotherms of human hemoglobin measured in distilled water and in solutions of sodium chloride in the concentration range from 0.02 to 3.0 M indicate that the oxygen affinity decreases up to about 1 M salt and then begins to increase. The isotherms obtained in the range from 0.02 to 0.6 M sodium chloride, at 37 degrees and pH 7.4, have been analyzed in terms of changes in Gibbs free energy of heme ligation, resulting from the differential interaction between the chloride ion and the two forms of hemoglobin. The maximal theoretical change in Gibbs free energy that chloride ion can exert on the oxygen binding of hemoglobin amounts to 4.9 +/- 0.2 kcal/mol (21 +/- 0.8 kJ/mol) of hemoglobin tetramer. A plot of the logarithm of oxygen concentration at half saturation versus the logarithm of the chloride concentration has a slope of 0.40, suggesting 1.6 apparent chloride sites per hemoglobin tetramer. Because the interaction between chloride and hemoglobin is dependent on pH, the apparent thermodynamic linkage between chloride and oxygen binding will also include the salt dependence of the Bohr effect at pH 7.4. The fractional change in Gibbs free energy, measured as a function of the chloride concentration, can be approximated by the binding isotherm between a protein and a ligand, using an association constant of 11 M(-1). Thus, if the number of oxygen-linked chloride sites is more than one per hemoglobin tetramer, these sites must be considered independent.


On the mechanism of genetic recombination: the maturation of recombination intermediates.

DNA molecules of the plasmid ColEl are normally recovered from wild-type cells as a set of monomer- and multimer-size rings. The data of this paper show that the multimer-size species are a product of genetic recombination. Multimer rings do not arise after transfection of purified monomers into bacterial host cells lacking a functional recA recombination system. Analogously, purified dimers, trimers, and tetramers, transfected into recA- cells, can replicate, but are constrained to remain in those conformations. Only upon transfection into rec+ cells can they regenerate the full spectrum of monomer- and multimer-size species. In this paper we trace the flow of genetic information from the monomer to the multimer state and back again under the guidance of the recA recombination system. The formation of multimer-size DNA rings is discussed as a natural consequence of the maturation of a Holliday recombination intermediate formed between two monomer plasmid genomes.


On the existence of a steady state in a biological system.

This paper deals with the existence, uniqueness, and stability of a critical point (steady state) in the case of a macromolecular system, such as an allosteric or polysteric protein, for which the first-order kinetic equations are nonlinear. It presents a brief outline of a rigorous proof (to be given in full elsewhere) that, in a restricted but not unrepresentative system of this kind, there always exists one and only one positive critical point and that this point is asymptotically stable in the large: no matter what its starting point, the system will always approach this point by some kind of relaxation process, however complex.


Synthesis of phiX174 viral DNA in vitro depends on phiX replicative form DNA.

A cell-free system that catalyzes phiX174 replicative form I (supercoiled circular duplex, RFI)-dependent phiX174 DNA synthesis has been isolated from Escherichia coli infected with phiX174 phage. The products formed with such preparations are viral strands as judged by hybridization to poly(U,G) followed by equilibrium centrifugation in CsCl. This phiX174 DNA-synthesizing involves formation of DNA-protein complexes that sediment in neutral sucrose with S values of 50, 60-70, and higher. The 50S complex contained a rolling-circle replicative intermediate DNA with an extended tail of single-stranded viral DNA. The DNA contained in the 60-70S region was a mixture of circular and linear single-stranded DNA, RFI, and RFII with an extended single-stranded tail. Such complexes have been isolated during in vivo progeny phiX174 DNA synthesis [Fujisawa, H. & Hayashi, M. (1976) J. Vriol. 19,409]. In vitro, maximal phiX174 DNA synthesis was shown to require the genetically defined proteins E. coli dna B, dna C, dna G, dna Z, rep. phiX174 gene A product, and other phiX174 coded proteins. The synthesis of phiX174 DNA is ATP-dependent and is inhibited by nalidixic acid and novobiocin but is resistant to rifampicin.


Effect of galactose oxidase, with and without prior sialidase treatment, on the viability of erythrocytes in circulation.

Previous studies have shown that sialidase-treated mammalian erythrocytes were rapidly eliminated from circulation. In contrast, chicken asialoerythrocytes remained fully viable. This investigation was undertaken to ascertain the reason for this difference in behavior as well as to determine the extent of the similarity of the physiological mechanism for the elimination from circulation of asialoglycoproteins and mammalian asialoerythrocytes. To that end, erythrocytes from dogs, rabbits, and chickens were each subjected to the action of galactose oxidase (D-galactose:oxygen 6-oxidoreductase; EC 1.1.3.9) both before and after sialidase (acylneuraminyl hydrolase; EC 3.2.1.18) treatment. The viability of the autologously transfused erythrocytes in circulation was monitored by Na2-51CrO4 labeling. Galactose oxidase had no deleterious effect on the viability of dog or chicken erythrocytes, nor did it restore the viability of dog or rabbit asialoerythrocytes. On the other hand, desialated chicken erythrocytes, which were fully viable, were rendered nonviable upon treatment with galactose oxidase. It may be concluded therefore that (a) the physiological mechanism of elimination of mammalian asialoerythrocytes from circulation is not the same as that for plasma asialoglycoproteins and (b) the treatment of chicken asialoerythrocytes with galactose oxidase results in the oxidation at carbons 6 of the galactosyl- or N-acetylgalactosaminyl residues, thereby rendering the erythrocytes nonviable.