[Elastic modulus of dental porcelains by dynamic method (author's transl)]. Using an equipment with sensitive vibretor-controller oscillater of elactrostatic drive system, we sought for the difference between elastic modulus of various kinds of dental porcelain and elastic modulus by firing method. We examined the relation between temperature of firing and elastic modulus as well. The obtained results are as follows: 1). Elastic modulus of low fusing porcelain of enamel color was 4.32 times 10(11) dyn/cm2 by air firing 3.95 approximately 4.63 times 10(11) dyn/cm2 by vacuum firing. Low fusing of porcelain of dentin color and the one of enamel color had the same elastic modulus. 2). Elastic modulas of high fusing porcelain of enamel color was 3.58 times 10(11) dyn/cm2 by air firing, 3.41 approximately 3.64 times 10(11) dyn/cm2 by vacuum firing. High fusing porcelain of dentin color and the one of enamel color were of the same elastic modulus. 3). Porcelain of opaque color for metal bond was 3.22 times 10(11) dyn/cm2 by air firing 3.97 approximately 4.22 times 10(11) dyn/cm2 by vacuum firing. When dentin color was added to opaque color elastic modulus was low (3.90 times 10(11) dyn/cm2). 4). Alumina porcelain of opaque color was 5.42 times 10(11) dyn/cm2 by air firing, 6.50 approximately 6.80 times 10(11) dyn/cm2 by vacuum firing. When dentin color was added to opaque color elastic modulus was very low (3.90 times 10(11) dyn/cm2). 5). Elastic modulus to various kinds porcelain changes according to temprature of fusing. And the highest elastic modulus is at the temperature which is 50 approximately 100 degrees C lower than final firing temperature.


[Study on the age-hardenable silver alloy (3 rd report). III. On the ageing process of dental Ag-Pd-Cu-Au alloy (author's transl)]. The precipitation hardening process of a dental silver base alloy, Ag-28 Pd-10 Cu-12 wt % Au, was studied by means of X-ray diffraction, hardness measurement and metallographic observations. After solution treatment at 900 degrees C for 30 min, specimens were subjected to anisothermal annealing at the rate of 1 degrees C/min. PdCu ordered phase and alpha2 solid solution (Ag rich phase) precipitated hetelogeneously at the grain boundaries and then grew up into each grain. Drastic increase in hardness was recognized with the spread of nodular region. Electron microscopic observation of these precipitates showed very fine lamellar structure. It is concluded that the age hardening of this alloy could be attributed to this grain boundary precipitation and the softening at the overaged stage to the second grain boundary reaction which produced very coarse lamellar structure.


[Studies on the dental gold-alloys (13). Precipitation hardening in gold-cobalt alloys (author's transl)]. The precipitation of cobalt from gold-rich solid solution was studied about Au-Co binary alloys containing less than 5 wt.% cobalt by correlating the results of metallographic observation and micro-hardness measurement to electrical resistivity measurements. The hardness curves of the alloys showed to hardness peaks after isothermal ageing below a certain temperature. It was considered that the first peak was due to formation of G. P. zone which was confirmed by reversion phenomenon. The second peak was due to growing of metastable cobalt rich precipitate. The maximum hardness obtained by ageing was higher in Au-5 wt.% Co alloy than in Au-1 wt.% Co alloy. Difference in growing mechanism of metastable precipitate was deduced from the kinetics data and the values of time exponent obtained by Johnson-Mehl equation.


[Studies on the dental gold-alloys (14). Effect of platinum addition on the AuCu-transformation by means of x-ray diffraction analysis (author's transl)]. X-ray diffraction studies were carried out so as to investigate the effects of 0.33-6.90 at. % additions of platinum on the ordering process of AuCu alloy. The stable existing temperature range of AuCu I was extended to higher temperature by the addition of platinum to stoichiometric gold-copper alloy, the ordering rate in these alloys were slower than that of binary AuCu. Changes in diffraction patterns showed a different sequence in ordering process at higher and lower temperature range. Orthorhombic AuCu II was only found in the alloy containing 0.33 at.% Pt at around 410 degrees C.


[Studies on the dental methacrylic resins (part 4). Flow properties and curing times of the pour methacrylic resins (author's transl)]. Flow properties and curing times of the pour resins consisted of polymethyl methacrylate and methyl methacrylate were investigated by the viscosity and the temperature measurements. The polymers with various article sizes and molecular weights and the monomer with 0.005 per cent hydroquinone were used the pour resins respectively. The initiator system of benzoyl peroxide--N, N-dimethyl-p-toluidine was used for the polymerization. The results were as follows: 1) The viscosities of the pour resins were increased with the time elapsed. That was for reasons of physical phenomenon, that is, dissolution of polymer into monomer. The logarithmic viscosities increased linearly in proportion to the time elapsed. 2) The viscosities of the pour resins were increased by the reduction of the particle size of the polymer and by the increase of the molecular weight of the polymer. 3) The curing times of the pour resins were reduced by the increase of the concentrations of benzoyl peroxide and N, N-dimethyl-p-toluidine, and by the reduction of the particle size and the molecular weight of the polymer respectively.


[A study on the cytotoxic action of gold-copper alloy by means of tissue culture (author's transl)]. Nine kinds of gold-copper alloy containing copper of various contents, such as 91% Au-9% Cu, 83% Au-17% Cu, 75% Au-25% Cu, 58% Au-42% Cu, 50% Au-50% Cu, 25% Au-75% Cu, 20% Au-80% Cu, 15% Au-85% Cu, 10% Au-90% Cu and two pure metals of copper and gold, were used to analyse cytotoxic action of gold-copper alloy. A cytotoxicity of these alloys and metals was observed by replicate culture using L-strain cells. The results obtained, were as follows; When the range of copper content was from 0 to 42%, the alloys showed no cytotoxic reaction. There was, however, strong cytotoxic action in the gold-copper alloys containing copper of 50% or more.


[Studies on the cytotoxic action of various composite resins by means of cell culture (author's transl)]. In order to investigate biocompatibility of composite resin, L strain cells were brought contact either directly with mixed resin or with immersion liquid, which was obtained by replacing with fresh medium twice for 48 hours, followed by utilizing these immersed medium as the second immersion liquid or the third, and results were assessed by cell multiplication rate calculated from cell nuclei counting per milliliter of medium, morphological observation and agar diffusion method, originally used by Guess et al. (1965) and later modified. The materials used were selected from the presently available composite resins, which were classified by composition and form for use provided by manufacturers, i. e, powder, paste, or liquid. Those which were classified were as follows; Types Pa-L-L (Paste-Liquid-Liquid), Pa-L (Paste-Liquid), Pa-Pa (Paste-Paste), Po-L (Powder-Liquid) and Po-L-Pa (Powder-Liquid-Paste).


Contribution to the reconstruction of the lower lip after tumour resection combined with neck dissection. Methods of reconstruction of lip defects following tumour resection must also be assessed in their suitability, as to whether it is possible to combine the simultaneous total excision of the regional lymphatic drainage with the achievement of a functionally and aesthetically satifactory result. The current methods of reconstruction in use in the Hamburg Clinic are demonstrated from this point of view. By viualising the lymphatic drainage in tumours of the lower lip, it is shown that there is no method of reconstruction which realises the principle of en bloc resection of tumours. Supported by the results of postoperative investigation, it can, however, be shown that the percentage of recurrence in the area of lymphatic drainage can still be kept extremely low by observing various principles.


Clinical Experience in the Cryosurgery of Haemangioma. The author using cryoapplicator of his own modification presents cryosurgery as a successful surgical technique in cases of haemangiomas involving the face, lips, tongue and oral cavity. From 1968 to 1974 in the Stomatological Clinic of Lublin 56 patients were operated upon using this method. The results were very encouraging. Total regression of haemangiomas and regeneration of normal mucosa with no noticeable scar resulted. A method of cryosurgery especially suitable for very young patients or for those who are poor risks because of associated disease and advanced age is suggested.


Curative treatment of malignant midline granuloma of the face. The symptomatology of the malignant centro-facial granuloma is described. A case and its treatment are demonstrated. Radiotherapy achieved complete healing. The possibilities of treatment are discussed and the author expresses the opinion that radiotherapy is the method of choice for treating centro-facial malignant granuloma.


Experiences on the sequela of maxillary sinusitis following closure of the causative oro-antral fistula. After describing the method of treating sinusitis in established oro-antral fistulae, which consists of irrigation of the maxillary sinus, antibiotic therapy and closure of the fistula, our experience gained on 75 cases checked postoperatively is presented. We found that a radical operation of the sinus, even later, was not necessary in most cases (present investigation of our clinical material showed 97.3 per cent). The inflammatorily a altered mucosa recovers after the elimination of the causative factor, which in this case is the closure of the oro-antral fistula. These findings thus correlate with those made by Obwegeser a and Tschamer (1957) and by Killey and Kay (1967).


New concept of morphogenesis of clefts in the lip, alveolus, and palate. The morphogenesis of clefts in the lip, alveolus, and palate is a process of both functional and formative adaptation of the affected mouth cavity to the disturbance which the cleft would represent in "pumping" the amniotic fluid. Only a normally developed portal venous system of the foetus, which is a continuation of the digestive canal through the liver, ensures efficient per-oral nutrition after birth. According to the findings known to date, the foetus feeds by "pumping" the amniotic fluid as early as the end of the third month of pregnancy. The amniotic fluid and nutritive substances contained in the fluid, which the foetus receives from the mother through the umbilical vein, are for the greatest part discharged through the foetus's skin. The morphogenesis of clefts proves the formative power of the tongue and its importance in the development of the mouth cavity as well as the ability of the normal growth response of the tissues around the cleft.


Mid-face anthropometry on the cephalometric radiograph in cleft lip and palate cases. An attempt is made to analyse mid-face deformities objectively in operated cleft lip and palate patients with the help of cephalometric techniques. Mid-face growth of cleft patients after the age of 10 years is compared with growth parameters of non-cleft subjects. This comparison indicates that some of the angles in the nasal area (Subnasale angle, Alaria angle) do not undergo any change in size with increasing age. Others which are subject to change (Rhinion angle, Pronasale angle) show no difference in the extent of growth between cleft patients and normal subjects inspite of different conditions at the age of 10 years. The lateral growth of the nasal soft parts (bialar distance) is largely independent of the lateral growth of the bony structures.


Conservative treatment of cervico-facial suppurations. The author prefers conservative treatment of suppurations in the cervico-facial area. It consists of evacuation of pus by puncture and simultaneous instillation of antibiotics. The technique for superficial and deep infections is described. On the basis of 470 cases treated the method is considered very efficient.


Teaching of physical diagnosis to dental students and oral surgery residents. To provide background information related to teaching of physical diagnosis, a survey was sent to all dental schools and approved oral surgery residencies. Seventy-eight percent of the schools and 90% of the residencies responded. Analysis of the data indicated only half of the reporting schools taught physical diagnosis to predoctoral students in a specifically designated course. Comparison of the type and duration of experience with that offered to medical students showed a great disparity between the two groups. The programs in physical diagnosis provided to oral surgery residents compared much more favorably with those offered medical students and were superior in some aspects. However, the total experience was not comparable to that which a resident in a medical specialty would obtain. It may be concluded from these data that the weakest link in the educational experience of the oral surgeon related to physical diagnosis lies in the predoctoral program.


Principles of treatment for temporomandibular joint ankylosis. An understanding of the growth and development of the temporomandibular joint (TMJ) is necessary for successful treatment of TMJ ankylosis. The concept of a growth center in the condyle is probably misleading; instead, the soft tissues of the orofacial region seem to provide the primary growth forces. As a result of this concept, methods of treatment should be reexamined.


Surgical correction of temporomandibular joint arthritis. Restoration of the contour of the articular eminence with a prosthesis has been successful when chronic sublaxation has resulted from flattening of the eminence. Use of a prosthesis is helpful in the treatment of patients with arthritic disease of the temporomandibular joint. A careful differential diagnosis is necessary to eliminate other possible causes of the patient's symptoms.


Eminectomy for the treatment of recurrent temporomandibular joint dislocation. Several techniques have been used to treat chronic dislocation of the mandible. Most of these techniques represent attempts at reducing the mobility of the TMJ. The eminectomy procedure is an attempt at restoring normal joint function without reducing mobility of the joint. We have presented two cases of chronic dislocation of the mandible that were treated successfully by removal of the articular tubercle and the lateral portion of the temporal bone. Although surgery of the TMJ area may be hazardous if approached without caution, we feel that the complications associated with this procedure are minimized if adequate care is taken in flap design and tissue dissection. On the basis of the excellent results of the eminectomy procedures reported in the literature and of our own experience with this procedure, we feel that this is the preferred treatment for chronic dislocation of the mandible.


Symptomatic osteoarthritis of the temporomandibular joint: report of a case. A case of osteoarthritis in the TMJ which manifested clinical symptoms, radiographic changes, and the classic microscopic alterations has been presented. Whether the condition was a primary or secondary form of the disease could not be unequivocally ascertained, as the symptoms preceded the injection of a sclerosing solution and a mandibular fracture, both of which could be significant contributing factors to a trauma-induced secondary osteoarthritic change. Nevertherless, a lack of symptoms in other joints would tend to exclude a generalized (primary) form of osteoarthropathy. In this regard, symptoms referable to the TMJ (to the exclusion of other joints) are more consistent with findings of secondary osteoarthritic change. Whether osteoarthritic changes were discernible by radiography in the TMJ before the traumatic episodes recorded in the history is unknown. Indeed, a developmental anatomic anomaly could not be ruled out. Regardless of whether the changes were the result of primary degenerative disease or chronic trauma, the symptoms were adequately resolved by surgical intervention.


Temporomandibular joint ankylosis secondary to Marie-Strümpell disease. Marie-Strümpell disease, or ankylosing spondylitis, is a severe arthritic disorder that may involve the TMJs. Bony alkylosis may result and cause lack of jaw mobility. Familiarity with this disease entity and other arthritic disorders is a necessity for the dentist and oral surgeons.


Bilateral enlargement of the mandibular coronoid processes in a patient with rheumatoid arthritis of the temporomandibular joints. A case of rheumatoid arthritis of the temporomandibular joint with enlargement of both coronoid processes has been presented. Limited excursions of the mandible were due mainly to the encroachment of the coronoid processes on the posterolateral surfaces of the maxilla. The condition was relieved by unilateral arthroplasty and bilateral coronoidectomies. The etiology of the enlarged coronoid processes is unknown. However, the condition does resemble that which occurs experimentally when condylectomy is performed and the ramus is shortened. In this case, shortening of the ramus could be attributed to condylar destruction by the arthritic condition.


Dynamic splints for rehabilitation after surgical treatment of ankylosis. Using strictly surgical techniques without rehabilitation often leads to a systemic pattern of relapse within approximately a year's time. With the technique proposed, we have obtained functional recuperation that has persisted for more than five years (Fig 4). We feel the splints are useful because they afford comfort to the patient, a shorter hospitalization period, and no risk of infection.


A correlation between microscopic numerical evaluation, clinical scoring and total collagen content in inflamed gingivae. The histopathological observation was carried out on 12 periodontally involved gingivae and the microscopic inflammatory index was utilized for a quantitative expression of the periodontal pathology. Namely, each of 40 to 50 sections obtained from one gingival biospy was microscopically examined concerning the changes in the epithelium of the periodontal pocket and the gingival lamina propria which were divided into several items tested. The total number of the indices for each item examined was defined as the microscopic inflammatory index in individual cases. This index showed a tendency to increase proportionally to the decrease of the amount of collagen per wet weight of gingiva adjacent to the gingival biopsy aforementioned. In evaluating periodontal diseases, this estimation appears to be more objective and reproducible compared with other various indices based on clinical observation.


A chlorhexidine-containing methacrylic gel as a periodontal dressing. The modification of a methacrylic gel for use as a periodontal dressing was attempted. The increased adhesion and rigidity of the resultant material appeared consistent with the clinical findings. Satisfactory retention of the dressing was found in 85% of those placed on a group of patients attending for periodontal surgery. The potential value of the methacrylic gel for carrying and releasing pharmacological agents useful in the management of lesions of the oral mucosa was assessed by incorporating chlorhexidine acetate into the dressing. In vitro and in vivo studies demonstrated effective release of the chlorhexidine from the dressing throughout the period of time a periodontal dressing is normally in situ. In conclusion the results suggested that the modified methacrylic gel fulfills the requirements of a periodontal dressing. Study to assess further the potential for this material to carry other pharmacological agents used in the topical treatment of lesions of the oral mucosa is indicated.


Antibacterial properties of periodontal dressings. The relationship between the build-up of bacterial plaque at the dento-gingival junction and the development of gingivitis is well established. The susceptibility of patients requiring periodontal surgery to the pathogenic potential of plaque would seem to necessitate the protection of the surgically treated area by a periodontal dressing until adequate plaque control by the patient is possible. In the light of clinical experience, an investigation was undertaken into the antibacterial properties of certain proprietary periodontal dressings and a zinc oxide/eugenol material. None of these materials showed any marked degree of antibacterial activity. One of these materials, Coe-Pak, had been used alone or combined with Cross Pack for all the patients in the clinical survey with very satisfactory results, and it is concluded that this material is successful because of its physical properties and not its antibacterial ones. Careful attention to asepsis, gentle and controlled tissue handling, correct technique, and thorough removal of plaque and calculus are the prerequisites for successful periodontal surgery. The protection of the surgical wound by a dressing of adequate physical properties aids in ensuring uneventful healing. The use of potent antibacterial agents in the dressing is not necessary; a physical barrier to salivary/bacterial contamination and food impaction may be the most important factor.


Clinical study of iodine as a chemotherapeutic agent for the control of dental plaque and gingivitis in man. The present investigation was conducted to study the effect of the local use of iodine solution as a chemotherapeutic agent on the degree of dental plaque formation and ongingival status in the presence and absence of mechanical oral hygiene. Thirty-six male dental students, 20 freshmen and 16 sophomores, at Case Western Reserve University, participated in the study. All subjects received a prophylaxis and oral hygiene instruction to reduce their plaque and gingival scoeres before the start of the experiment. The 20 freshmen dental students were selected for the test of iodine used in a form of mouthwash. The subjects were randomly divided into two groups. One group received a 0.02% iodine mouthwash, the other a placebo solution of distilled water. Each student was randomly assigned to brush and floss the right or left side of his dentition once daily. The students rinsed with 7.5 ml. of the assigned solution twice daily. The 16 sophomore dental students were selected for the test of iodine applied topically on the tooth surfaces. The subjects were assigned to a randomized block design in which each quadrant received one of the following treatments daily: topical application of iodine solution (2.0% I2 and 2.4% NaI) with brushing and flossing, brushing and flossing only, topical application of iodine solution only, and topical application of distilled water only...


Odontogenic fibromyxoma arising from the periodontal ligament. A case is reported of an intraosseous odontogenic fibromyxoma which presented as an epulis and appeared to arise from the periodontal ligament of an upper lateral incisor. True neoplasms rarely present in this fashion, and the literature reveals no report of an intraosseous myxomatous neoplasm exhibiting such clinical features. Evidence supporting the periodontal ligament origin of the lesion is presented and discussed.


Dental prophylaxis procedures in control of periodontal disease in Lucknow (rural) India. Frequent professional scaling and regular tooth brushing are the main public health measures available for preventing and controlling periodontal disease but their frequency and efficacy are still incompletely understood. This investigation was carried out on 1,416 rural children and 189 factory workers in Lucknow area in the age groups 14 +/- 1, 17 +/- 1 and 28 +/- 2 years of age to evaluate the optimum requirement of these measures to the extent they will be economical and usable in the public health programs. The prevalence of gingivitis and periodontal disease in Lucknow children and adult samples was found to vary between 93 to 100%. Periodontal disease (including gingivitis and loss of attachment) and calculus accumulation showed considerable reduction (P less than 0.01) with any type of treatment. Scaling alone will not reduce the plaque formation for which regular tooth brushing is essential. Yearly and half-yearly scaling along with tooth brushing instructions will considerably improve and maintain the oral hygiene thereby reducing the prevalence and severity of periodontal disease, plaque, and calculus accumulations. However, more intensive measures (quarterly prophylaxis) will further improve the periodontal health and reduce calculus accumulation. The apical migration of the epithelial attachment can practically be stopped by rendering scaling half yearly, without any instructions in oral hygiene and elimination of dental plaque.


A new concept of periodontal diseases.

A new concept of periodontal diseases. Both the inflammatory and noninflammatory types of periodontal diseases begin with an aseptic, traumatic destruction of alveolar bone, caused by traumatizing parafunctions and followed by changes in the gingiva. The latter may or may not have a superimposed infectious inflammatory process. A new concept to fit these facts is proposed: periodontal diseases are autodestructive processes in the masticatory system, with or without superimposed septic inflammation. To confirm the theory of autodestruction, direct evidence as well as indirect but conclusive evidence is given for the existence of traumatizing forces in the masticatory system, for traumatic destruction of alveolar bone, for changes in the gingiva following destruction of alveolar bone, and for the parafunctions by all persons afflicted by periodontal disease. It is concluded that traumatizing parafunctions are the main factor in the etiology of periodontal diseases and that in therapy recurrences are inevitable unless parafunctions have been eliminated.


A variation in complete mandibular impression form related to an anomaly of the mylohyoid muscle. 1. Mylohyoid eminentiae form on the lingual flange of a denture impression when a gap exists in the mylohyoid muscle. The gap, when void of resistant structures, allows the overlying mucous membrane to sag into the aperture under pressure from impression material. 2. The eminentiae may be considered clinically unimportant, because they can be altered if necessary without affecting the serviceability of the denture.


Use of the remount jig as an aid in relining upper dentures. A remount jig record is used to reposition the teeth of an upper denture reline in their original position. A face-bow record is used to position the upper edentulous cast in the correct relation to cranial planes. The impression may be developed as is done in any other impression procedure, and the repositioning can be accomplished in the laboratory with reasonable assurance that the upper denture is positioned occlusally as it was when the denture was constructed originally. This procedure relieves the dentist of the monumental task of making a reline impression and adjusting the position of the denture in one three-minute operation.


Modification of stresses in alveolar bone induced by a tilted molar. Stresses induced in the supporting bone by a tilted molar tooth under load have been investigated by both the photoelastic and the finite element model systems. The following conclusions were reached. 1. Altering the angle of the load applied to the unsupported molar from 0 (axial) to 30 degrees resulted in a fourfold increase in compressive stress in the supporting bone mesial to the tooth. 2. Increasing the load from 30 to 90 pounds while maintaining a 30 degree angle of application resulted in a linear increase in the shear stress on the supporting bone mesial to the tooth. 3. Following the placement of a fixed partial denture, the induced stress at a point on the mesial aspect of the molar tooth, subjected to a 60 pound load at 30 degrees to the long axis, was reduced from 241 to 43 p.s.i. 4. The introduction of a fixed partial denture resulted in a decrease in the compressive stress in the bone adjacent to the apex of the mesial root of the molar from 481 to 174 p.s.i. 5. A distributed 120 pound load applied over the length of the fixed partial denture compared against individual tooth loadings of 60 pounds revealed that placement of the fixed partial denture favored the tilted molar at the expense of the premolar.


The immediate palatal plate.

The immediate palatal plate. The immediate palatal plate is therapeutically beneficial for relief of temporomandibular joint pain, for reduction of occlusal trauma with and without selective grinding, for orthodontic tooth movement as a disarticulating device, and for relief of pericementitis subsequent to periodontal surgery. The immediate palatal plate is durable and well tolerated by patients and has established itself to be more than just an interim appliance.


Compressive facial splints.

Compressive facial splints. A method of constructing long-term compressive splints for the regions of the head and neck using available materials has been described. These splints have been useful where continuous pressure is needed to promote healing or enhance treatment over long periods of time.


Chronic myofascial pain-dysfunction syndrome with chest pain. A patient with a myofascial pain-dysfunction (MPD) syndrome with pain radiating into the chest has been described. A direct relationship between a dental malocclusion and the chest pain was confirmed by tests. The patient was treated for MPD syndrome related to the malocclusion, and the chest pain symptoms were relieved. This report demonstrates the need for the dentist to consider not only the muscles of mastication in the management of problems of the neuromuscular apparatus but also the delicate balance which exists between the masticatory apparatus and the postural muscles of the head and neck.


The bony residual ridge in man.

The bony residual ridge in man. The bone which fills in the socket after tooth extractions was investigated in 120 dry skull specimens and 100 radiographs in which one or more teeth had been missing for at least three months. The bony content of the socket was of the trabecular type. This trabecular bone was well differentiated from the adjacent cortical bony plates. In buccolingual sections, the residual crest was formed by dense trabecular bone, clearly differentiated from the cortical plates as well as from the less dense trabecular bone that was deeper within the former sockets. From the occlusal aspect, the crest of the edentulous surface had shifted lingually when compared to the original position of the teeth before extractions. From the lateral aspect, the residual ridge formed a concavity or went straight between the alveolar crests of the adjacent remaining teeth. When several teeth were missing, the concavity was more pronounced than when a single tooth was missing.


Restoration of immunocompetency by lymphocyte transfusion. A female patient with metastatic osteosarcoma was given a lymphocyte transfusion from her brother, cured of the same histologic type of tumor ten years earlier. Prior to the transfusion the patient was anergic. Following lymphocyte transfer cutaneous reactivity to DNCB was restored. Skin reactivity to mumps and varidase antigens was specifically transferred. Whole lymphocyte transfer is a feasible method for restoring immune competence in the anergic cancer patient.


Investigation of carbohydrate metabolism and somatomedin in osteosarcoma patients. Altered carbohydrate metabolism associated with fibrosarcomas and chondrosarcomas has been well-documented in past literature. This report describes abnormal carbohydrate metabolism in 2 osteosarcoma patients, and abnormalities in growth hormone and somatomedin serum levels. Experimental evidence is presented showing in vitro suppression of osteosarcoma tumor cell proliferation by 17 beta Estradiol. Estrogen inhibition of linear bone growth, cartilage proliferation, and somatomedin is discussed with reference to possible estrogen therapy in osteosarcoma.


The platelets in preleukemia and myelomonocytic leukemia. Ultrastructural cytochemistry and cytogenetics. Light and electron microscopic studies of platelets from 16 patients with myelomonocytic leukemia or "preleukemia" revealed major morphologic alterations in 15 and minor ones in 1. Although variable in severity from case to case, the changes present followed a distinct pattern. In most cases there were two platelet populations, one morphologically normal and one morpholigically abnormal. The most salient changes pertained to size (giant forms), shape (the platelets being rounded and probably spheroidal), decrease or absence of the microtubules, and increase in immature elements. A striking feature was the variation in size and shape of the granules, with truly giant forms (up to 2.5 mum) being present. In cytogenetic studies in 14 cases, there was no correlation between the chromosomal changes and the various types of platelet anomalies.


[Chronic myelogenous leukaemia as a possible consequence of immunosuppressive treatment of nephrotic syndrome (author's transl)]. A boy, aged 14, suffered since his 5th year from nephrotic syndrome. During the first 7 years he had been treated with adrenocorticosteroids, but his condition hardly improved. Then a cyclophosphamide treatment was started with a total dosis of 5 g in 50 days. The nephrotic syndrome had disappeared, but relapsed 3 years afterwards, this time accompanied by chronic myelogenous leukaemia. The possibility of the onset of chronic myelogenous leukaemia in connection with the immunosuppressive therapy (adrenocorticosteroids and cyclophosphamide) is discussed.


Chronic granulomatous disease: an inherited disorder of phagocytosis in a Maori ancestry. Chronic granulomatous disease, in which abnormal susceptibility to infection is caused by an inherited defect in phagocytic cells, has been diagnosed in three brothers. Two brothers had repeated bacterial infections of the skin, superficial lymph nodes and lungs from infancy and died aged 27 months and 13 months. Characteristic suppurating granulomata were found in many organs. The diagnosis was established in both during life, and in the third asymptomatic brother shortly after birth, by studies of phagocytic function which included tests for nitroblue-tetrazolium reduction, hexose monophosphate shunt activity and bactericidal capacity. Their mother and a maternal aunt, both Maoris with no known Caucasian ancestry, were identified as carriers of the presumed sex-linked recessive gene. The clinical features of the disease and the laboratory methods for diagnosis are described.


Early experience with total knee replacement. This paper presents a review of two years' experience with the geometric total knee replacement. The results of 23 arthroplasties in 22 patients are discussed. Relief of pain was consistent and dramatic, movement was increased postoperatively in only three patients, but imporvement in overall function occurred in 20 of the 22 patients. There was one failure requiring arthrodesis. In this patient, six months after surgery the medial tibial condyle collapsed and the polyethylene tibial component fractured. This complication has not been reported before. Early results are encouraging. Total knee joint replacement is a useful procedure in advanced arthritis when arthrodesis is the only alternative.


Smoking behaviour and respiratory health in teenage sample: the rotorua lakes study, 1. A survey in a New Zealand high school compared boys and girls, Maori and European, aged 13 to 15 years, and found differences in smoking habits. Smoking was most prevalent in Maori students of both sexes, and least in European girls, who appeared to be most influenced by home factors such as father's occupational status and older siblings' habits. Maori students and European boys showed relationships rather to the habits of the peer group. Findings were comparable with earlier studies suggesting little secular change in the smoking habits of this age group. Current smokers in all sex/race groups had higher current respiratory morbidity scores than non-smokers and ex-smokers, and smoking partly accounted for racial differences in morbidity.


Medical services at a music festival.

Medical services at a music festival. A three-day open air musical festival attended by approximately 20 000 people was held at Ngaruawahia in January 1973. A medical service was provided and staffed mainly by medical students, nurses and young medical graduates. There were 1998 patient visits to the medical area, the five most common complaints being sunburn, headaches, minor foot trauma, gastroenteritis and lacerations which collectively accounted for 75 percent of the diagnoses. The medical services provided are discussed and recommendations for future festivals made.


Youthline Dunedin: an evaluation of a telephone counselling service. Youth Dunedin is a telephone counselling service which has been in operation for over two years. The type and pattern of calls is discussed, and results of a survey aimed at eliciting how well the youth of Dunedin know of the operations are presented. The trend in the number of calls is forecast. The calls over a wide range of concerns with no noted daily or monthly pattern. There is an upward trend in the frequency of calls.


Solo mothers after delivery at Christchurch. A questionnaire was sent to 130 single mothers who kept their infants after delivery. The questionnaire was designed to find out the needs if any, of solo mothers. The Social Welfares Services were not fully utilised.


Performance of the Dalkon Shield intrauterine device. A modern second generation intrauterine device, the Dalkon Shield has been assessed at the National Women's Hospital. The markedly low expulsion rate represents a real advance in intrauterine contraception. Pregnancy rates are comparable with other modern devices. Patient acceptability is higher than with earlier devices.


Pediatric mandibular fractures.

Pediatric mandibular fractures. This article is a study of the experience with mandibular fractures at a large pediatric hospital. A total of ninety-four mandibular fractures in sixty-three patients is reviewed. The cause, location, male-female ratio, occurrence of multiple fractures, and associated problems are studied.


Comparison of two submandibular incisions on the motor function of the lower lip. The usual submandibular surgical approach to the mandible carries with it the risk of injury to the mandibular ramus of the seventh nerve. This may result in transient or permanent palsy of the lip. In a study of twenty operative procedures, of which half were performed at the conventional level and the other half at a lower level, an interesting contrast in facial nerve involvement was noted: 50 per cent at the conventional incision and none at the inferior one.


The styloid or "Eagle" syndrome: an unexpected consequence. The development and pathogenesis of the elongated styloid process with a calcified stylohyoid ligament are reviewed and discussed. A case report is presented to demonstrate that, although the related symptoms may be mild, unless the patient is aware of the cause of the discomfort, a "cancerophobia" may cause great emotional distress.


The effect of steroid hormones on buccal mucosa of menopausal women. The effects of local application of estrone and progesterone on the oral mucosa was studied in sixty-one patients. These included forty-one postmenopausal women with various subjective oral complaints, ten postmenopausal women with no oral complaints, and ten normally menstruating women. Subjective complaints (dryness, bad taste, burning sensation, and viscous saliva), quantity of saliva, and histologic changes in buccal mucosa were evaluated before and after treatment. Treatment comprised three modalities: an ointment containing estrone alone; another ointment of estrone and progesterone; and a third with a placebo base. These were massaged three times daily over the gingivae and oral mucosa for 30 days. A significant increase in secretion of saliva was observed with all three treatment modalities. Biopsies showed marked proliferative changes with all three types of ointment. A moderate improvement in subjective complaints followed all types of medication. These results indicate no specific effect of female sex hormones on the factors considered in this study. It appears that simple, repeated massage with any suitable ointment base is an effective method of inducing proliferative changes in atrophic buccal mucosa, increasing salivary secretion, and alleviating some of the subjective oral complaints of postmenopausal women.


The C.C.A. syndrome (congenital contractural arachnodactyly): a new differential syndrome for Marfan's syndrome and homocystinuria. The first case in the dental literature of congenital contractural arachnodactyly (C.C.A. syndrome) is presented. This newly delineated syndrome is an autosomal dominant heritable disorder of connective tissue. Its similarities to Marfan's syndrome and homocystinuria, as well as other syndromes, are discussed. The lack of cardiovascular disease, specific ocular anomalies, and mental retardation are presented in the differential diagnosis of the C.C.A syndrome with Marfan's syndrome and homocystinuria.


Primordial cyst versus keratocyst.

Primordial cyst versus keratocyst. The term primordial cyst was introduced in 1945 to identify the odontogenic cyst formed from enamel organ before calcification occurred as part of a classification based on development, structure, and radiographic appearance. The term odontogenic keratocyst was introduced in 1956 to describe cysts of the jaw exhibiting keratinization of their lining. Periodontal, dentigerous, primordial, residual, and gingival cysts may exhibit keratinized linings and can properly be identified as odontogenic keratocysts on the basis of their histologic appearance but may also be identified by their "developmental" designation. There is no justification for considering odontogenic keratocyst as a synonym for primordial cyst.


Oral nodular excrescences in epidermolysis bullosa. Two brothers are reported with what appears to be a recessive and dystrophic type of epidermolysis bullosa. The oral lesions seen in these patients consisted of small fibrous nodules that were liberally distributed on the bound-down mucosa. These lesions have not been previously reported. One of the offspring of these patients, who was not affected by epidermolysis bullosa, was missing a large number of teeth.


Mucoepidermoid carcinoma arising within a Warthin's tumor. A case of low-grade mucoepidermoid carcinoma arising within a Warthin's tumor is reported. The carcinoma appeared to have originated from the hyperplastic atypical epithelium of the Warthin's tumor. It did not infiltrate the capsule of the lymph node in which the Warthin's tumor developed. After 6 years of follow-up, there is no evidence of recurrence or metastasis. The literature on malignant Warthin's tumor is reviewed.


Nodular fasciitis.

Nodular fasciitis. The case of a highly unusual lesion present in the mandibular area is reported. Operative intervention was successful, and healing was uneventful. The pathologic diagnosis was difficult to make because of the nature of the lesion.


Felty's syndrome.

Felty's syndrome. The clinical and pathologic findings of Felty's syndrome are discussed. A case is presented which demonstrates the nonspecific inflammatory oral lesions commonly seen with this syndrome. The role of the dentist in relating these nonspecific lesions to the basic disease process is emphasized.


Variations in the interpretation of periapical radiolucencies. Comparison of the first and second interpretations by means of measurements on enlarged tracings of forty-five periapical radiolucencies by ten experienced dentists revealed an average relative error of interpretation of 21 per cent for the area measurements of the readily defined radiolucencies and 37 per cent for the area measurements of the diffuse radiolucencies. Comparing the dentists, the relative error of interpretation by means of measurements of the area varied from 14 to 32 per cent for the readily defined radiolucencies and from 23 to 52 per cent for the diffuse radiolucencies. The differences in interpretation were more obvious in the area measurements than in the measurements of the largest distance between the root surface and the outline of the radiolucency or the largest diameter.


Automatic processing of intraoral films in dental schools. Most of the active and provisional members of the American Association of Dental Schools used automatic processors for developing, fixing, and washing intraoral x-ray films. The S. S. White Auveloper was the processor most commonly used, the next most common being Litton's Profexray. Processing solutions were changed, on the average, two to three times a month. The quality of developing, fixing, and washing was generally reported to be satisfactory. The one major drawback to automatic processing was breakdown and malfunction of equipment.


Fibro-osseous lesion of the mandible mimicking chronic osteomyelitis. An account is given of the clinical, radiologic, and pathologic, features of a special form of fibro-osseous lesion of the mandible. The material consists of fifteen cases (eleven females and four males). Two cases are described in detail. Together with Case 1, a probably unique series of radiographic pictures is presented, showing the development of the disease.


Ameloblastoma of the jaws in Nigerian children. A review of sixteen cases. The records of sixteen patients under 18 years of age with ameloblastoma of the jaws treated at the University College Hospital, Ibadan, Nigeria, within the last 10 years were examined. In fifteen of the sixteen cases, the tumor was found in the mandible, with the symphysis being affected in seven cases. The ease with which the monocystic type of the tumor may be confused with a dentigerous cyst is pointed out. The different methods of treatment of ameloblastoma of the jaws in children are discussed.


Craniometaphyseal dysplasia. Report of a case. Craniometaphyseal dysplasia, often referred to as Pyle's disease, is a hereditary disease involving the expansion of the metaphyses of the long bones, giving the appearance of an Erlenmeyer flask. There is diffuse hyperostosis of the entire cranial vault, along with absence or decreased development of the paranasal sinuses. In the case presented here the mouth demonstrated an abnormality wide maxilla with a slight palatal vault. Genetically, this appeared to be a dmoninant form of dysplasia.


The disturbances in odontogenesis in epidermolysis bullosa hereditaria letalis. The disturbances in odontogenesis in a case of epidermolysis bullosa hereditaria letalis are described, with particular emphasis on the morphologic alterations in the ameloblasts and on the nature of vesicles in the enamel organ. These latter structures are compared to those found in the skin.


Scanning and transmission electron microscopy of odontogenic keratocysts. The ultrastructural characteristics of the superficial cells of the epithelial lining of odontogenic keratocysts were studied. Examples of both the parakeratinized type and the less common orthokeratinized variant were examined. Scanning electron microscopy reveals that the morphology of the two cyst types is distinctly different. In parakeratinized cysts the transition of the epithelial cells into parakeratin is readily apparent and the epithelial surface is sparsely covered with parakeratin squames. In the orthokeratinized type the surface morphology is more uniform and is entirely covered with a leafy layer of keratin squames. The morphologic differences between the parakeratinized and orthokeratinized cysts may reflect differences in their biologic behavior.


Odontogenic tumors in an African population. Analysis of twenty-nine cases seen over a 5-year period. The patients reported on here were seen and treated in the Department of Oral Surgery and Pathology, Division of Dentistry, Lagos University Teaching Hospital, between September, 1969, and September, 1974. Materials for histopathologic examination came from tissues removed at biopsy or surgical excision of the lesions. Out of a total of about 200 benign and malignant lesions of the oral cavity seen during the 5-year period (all cysts excluded), twenty-nine (15 per cent) were tumors arising from the odontogenic tissues as follows: ameloblastoma, nineteen; ameloblastic fibroma, two; adrenomatoid odontogenic tumor, two; ameloblastic fibro-odontoma, one; odontoma, two; cementoma, two; and calcifying odontogenic cyst, one. The author had the privilege of seeing all the patients and examining all the biopsy and surgical specimens.


Calcifying epithelial odontogenic tumor. A histologic, histochemical, fluorescent, and ultrastructural study. A previously unreported calcifying epithelial odontogenic tumor (CEOT; Pindborg tumor) occurring in a Negro patient is presented. Only 12 per cent of these neoplasms have been found in nonwhite patients. Ultrastructural and histochemical studies indicated that the amorphous, acellular, eosinophilic substance present within the tumor was not amyloid. The presence of only sparse calcifications is an unusual histologic variant. No relationship between neoplasm and reduced enamel epithelium could be demonstrated.


Endodontic emergency dilemma: leave tooth open or keep it closed? Various methods of emergency endodontic treatment for teeth with vital pulps have been suggested, and some authors have advised that the access be left open if the tooth is tender to percussion. This study evaluated 225 open and closed teeth which were referred after emergency treatment where pulps had been vital. When the access had been left open, a statistically significant greater number of appointments were needed to complete treatment and more intratreatment exacerbations occurred than when the tooth was kept sealed.


The diagnostic correlator: an endodontic teaching device. A chart is proposed as an aid to assist students and practitioners to correlate clinical information and arrive at an accurate endodontic diagnosis. A brief description of current displays, the clinical examination, and an endodontic disease classification is given. A discussion and examples of how to use the chart are presented. The chart has been found to be a useful teaching aid.


Exposure factor determination.

Exposure factor determination. Differences in radiation output between dental x-ray generators operated with a given electrical input often discourage the practitioner from trying to use supplemental x-ray techniques. Methods are described by which the exposure time is easily computed for an generator, regardless of cone length, kilovoltage, milliamperage, or idiosyncrasies of output.


An alternative approach to dose reduction in dental radiography. A responsible approach to dose reduction in dental radiography requires that relative exposure be related to the specific diagnostic task performed. All but the most demanding tasks can be performed when suitable film is used in conjunction with high-speed screens. Placing the source of radiation inside the mouth permits radiographic information to be recorded on an improved Polaroid cassette that has a relatively high quantum efficiency. As a result, the radiation dose can be significantly reduced in a versatile system which provides for instantaneous processing and interpretation from prints rather than negatives.


The development of drug-resistant strains of Eimeria maxima in the laboratory. The development of strains of Eimeria maxima resistant to buquinolate, methyl benzoquate, clopidol, sulphaquinoxaline and robenidine is described. It was not possible to standardize a schedule of inoculations and drug administration, which would enable the development of resistance to the different drugs to be compared directly. Resistance developed most readily to the quinolones. One robenidine-resistant strain proved to be drug-dependent. Dinitolmide showed unusual effects upon sporogony and three attempts to develop resistance against this activity failed. Chicks previously immunized with the parent strain were completely protected against infection with the drug-resistant strains.


Eimeria tenella in chickens: development of resistance to quinolone anticoccidial drugs. The development of drug resistance by the present Houghton strain of Eimeria tenella to the quinolones, methyl benzoquate and buquinolate, was found to take place after a single experimental passage. The development of resistance was independent of drug selection pressure and showed cross resistance to other quinolones, but not to amprolium and robenidine. When the Weybridge, Beltsville and Elberfeld strains of E. tenella were compared under similar laboratory conditions, the Weybridge and Elberfeld strains developed resistance to methyl benzoquate after 6 passages and the Beltsville after 5. Studies on the response of the Houghton strain to methyl benzoquate and buquinolate revealed that the drugs did not completely control the infection as measured by weight gain and that oocyst production was not suppressed. These observations indicate that the strain had already acquired some resistance to these drugs. This was confirmed by examining the resistance to methyl benzoquate of a culture of the Houghton strain of E. tenella which had been stored frozen in liquid nitrogen since 1969. This showed full sensitivity to the drug and developed resistance after 8 passages. This suggests that drug tolerance has been acquired by the Houghton strain since 1969. Oocyst lines were established from the Houghton strain by infecting single birds with approximately 10 oocysts. Eleven of these lines were found to be sensitive to methyl benzoquate, and nine to give rise to resistant parasites. It is concluded that the Houghton strain is contaminated by a small number of resistant oocysts which can be eliminated from a culture by dilution of the challenge inoculum. One of these Houghton oocyst lines, sensitive to methyl benzoquate, developed resistance after 8 serial passages.


[A comparison of paying patients in private practice and in public dental service--found from the Harstad-study 1974]. Since 1950, the Public Dental Service (PDS) has gradually been developed in Norway. In addition to rendering free and systematic treatment to children aged 6--17 years, which has priority, the PDS also offers treatment to other categories of patients at fixed fees, generally lower than those in private practice. The purpose of the present study was to elucidate the impact made by PDS on the dental treatment pattern within one particular area (the district of Harstad with a population of approximately 29,000). Furthermore, the study included a description of the clientele in the PDS, excluding the "free clientele" aged 6--17, in relation to that treated in private practice. During a limited period in February--March 1974, all the 9 dentists in the PDS treating "paying clientele" and all the 9 private practitioners in the district, filled in a questionnaire by each patient visit (course of treatment) (Fig. 1). In addition to the information on social and demographic  characteristics, data were also collected on dental treatment pattern, the treatment presently rendered, and the presence of teeth and possible dentures (Fig. 1). Four--fifths of the visits made by "paying clientele" were made in private practice, only one--fifth in the PDS. In private practice, rural people, women and people of young age were underrepresented. Children under 6 years of age comprised 3% of the clientele in private practice and 9% in the PDS. No significant difference was found between the two types of practice regarding the social class composition of the clientele. Dental status as measured by the occurrence of teeth and dentures was generally poorer among the PDS patients, seemingly due to the overweight of rural people and of those with an irregular or occasional treatment pattern. Totally 40% of all visits were made by regular treatment attenders. 20% of the services delivered were prophylaxes and/or periodontics, 56% were conservative and/or endodontic treatments. The introduction of the FDS in the district some 10--15 years ago has conceivably contributed to an overall increase in the demand for dental services, and to an improvement of denial treatment patterns. During this period, the number of public dentists has increased from 2--3 to a total of 12. Correspondingly, the number of private practitioners has increased from 5 to 9, of whom 2 work part time. The treatment attendance of some population subgroups is, however, still lagging behind: rural people, small children and persons over 50 years of age, and particularly people belonging to lower socio-economic brackets.


[Sale and use of fluoride tablets in Norway]. Fluoride tablets and lozenges have been marketed in Norway since 1963. Until 1971, the consumption was very moderate and less than one per cent of the children between 0 and 12 years of age used fluoride tablets or lozenges. In 1971 a campaign of information was started. Since then it has been a marked increase in the sale (Fig. 1). Estimated from the sale figures, about 15--20 per cent of all Norwegian children used fluoride tablets or lozenges in 1974. There were, however, rather large variations between the different counties (Table 1). In the present paper, the importance of giving fluoride supplement from early childhood is emphasized. The role of dentists, physicians, dental hygienists, and health nurses in promoting dental health in children is discussed.


Antigen mobility in membranes and complement-medical immune attack. The complement fixing activity of liposomes containing cholesterol, dimyristoylphosphatidylcholine (or dipalmitoylphosphatidylcholine), and 3 mol % of cardiolipin has been studied as a function of cholesterol concentration by use of human syphilitic serum containing cardiolipin-specific (Wasserman) antibodies. It is found that complement fixation increases rapidly for cholesterol concentrations above 35 mol %. Spin label studies have been used to study the incorporation of cardiolipin in the relatively rigid phase of binary mixtures of cholesterol and dimyristolphosphatidycholine (or dipalmitoylphosphatidylcholine). It is concluded that cardiolipin is included in such a phase of these lipids for cholesterol concentrations above 35 mol %. These results indicate that a relatively rigid lateral distribution of this monovalent antigen in the plane of the membrane facilitates complement fixation and concomitant complement-mediated membrane damage.


Attraction of the oriental fruit fly, Dacus dorsalis, to methyl eugenol and related olfactory stimulants. The attraction of male oriental fruit flies to methyl eugenol and 34 analogues was investigated quantitatively using the characteristic feeding response. Methyl eugenol was the most active compound studied, with a feeding response to 0.01 mug, but saturation of the allyl side chain or replacement of allyl by allyloxy produced compounds almost as effective. Replacement of the methoxy groups by methylenedioxy, methyl, or chloro groups abolished all response. The ring geometry of the methoxy groups was critical, with orthodimethoxy most active and meta-dimethoxy inactive. Replacement of methoxy with hydroxy, methylthio, or amino groups did not abolish the response. The failure of the oriental fruit fly to respond to the methyl and chloro isosteres of methyl eugenol was contrasted with the response of a human odor panel which perceived these compounds as having weak floral odors.


Preparation and microbial decomposition of synthetic [14C]ligins. A definitive assay for microbiological and biochemical research on the biodegradation of lignin was developed using radioactive synthetic lignins specifically labeled in the side chains, aromatic rings or in the methoxyl groups. The [14C]lignins were prepared by oxidative polymerization with peroxidase and H2O2 Of specifically labeled coniferyl alcohol (4-hydroxy-3-methyoxycinnamyl alcohol). The synthetic polymers were shown by spectroscopic and chemical methods to contain the same intermonomer linkages found in natural lignins. Incubation of the [14C]lignins with known lignin-degrading fungi and with a forest soil resulted in 14CO2 evolution.


Interaction of cholera toxin and membrane GM1 ganglioside of small intestine. Ganglioside GM1 was isolated from the small intestinal mucosa of man, pig, and beef and amounted to 0.1, 2.0, and 43 nmol per g fresh weight, respectively. These differences in GM1 content were associated with a quantitatively differing ability of the mucosal cells to bind cholera toxin. Human cells bound about 15,000 toxin molecules when saturated with the toxin, porcine cells 120,000, and bovine cells 2,600,000 molecules. The association constant (KA) of the cholera toxin binding was, for cells of all three species, about 10(9) liters/mol. Exogenously added GM1 ganglioside was incorporated in intestinal mucosal cells as well as in intact rabbit small bowel. The increment in GM1 was associated with a correspondingly increased number of binding sites for cholera toxin, whereas KA was unchanged. GM1 incorporation increased the sensitivity of the rabbit small bowel to the diarrheogenic action of cholera toxin. Vibrio cholerae sialidase hydrolyzed isolated intestinal diand trisialogangliosides to GM1. However, the enzyme did not change the ganglioside pattern of intestinal mucosa, had very little influence on the number of toxin binding sites on intestinal cells, and did not alter the sensitivity of the small bowel to the diarrheogenic action of the toxin. These results demonstrate a relationship in the intestinal mucosa between the GM1 ganglioside concentration, the number of binding sites for cholera toxin, and the sensitivity to the biologic action of the toxin. Thus, the study strongly supports the concept that the GM1 ganglioside is the intestinal binding receptor for cholera toxin.


Modification of the 5'-terminus of mRNA by soluble guanylyl and methyl transferases from vaccinia virus. RNA guanylyl and methyl transferases have been solubilized from vaccinia virus cores. The guanylyl transferase specifically adds a GMP residue to the 5'-terminus of unmethylated vaccinia virus mRNA to form the structures G(5')ppp(5')Gp- and G(5')ppp(5')Ap-. Studies with [alpha-32P]GTP and [beta, gamma-32P]GTP indicated that only the alpha-phosphate is transferred. In the presence of S-adenosylmethionine, the methyl transferases convert the blocked 5'-termini to m7G(5')ppp(5')Gmp- and m7G(5')ppp(5')Amp-. Similarly, the enzymes can modify synthetic poly(A) to form the structure m7G(5')ppp(5')Amp-.


Site-specific cleavage of single-stranded DNA by a Hemophilus restriction endonuclease. Single-stranded viral DNA of bacteriophage f1 is cleaved into specific fragments by endo R-HaeIII, a restriction endonuclease isolated from Hemophilus aegyptius. The sites of the single strand cleavage correspond to those of the double strand cleavage. A single-stranded DNA fragment containing only one HaeIII site is also cleaved by this enzyme. This observation suggests that the reaction of single-stranded DNA cleavage does not require the formation of a symmetrical double-stranded structure that would result from the intramolecular base-pairing between two different HaeIII sites. Other restriction endonucleases may also cleave single-stranded DNA.


Cholera toxin activation of adenylate cyclase in cancer cell membrane fragments. Activation of adenylate [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] by cholera toxin (84,000 daltons, 5.5 S) is demonstrated in plasma membrane fragments of mouse ascites cancer cells. The activation of adenylate cyclase is mediated by a macromolecular cyclase activating factor (MCAF), which has a sedimentation constant of 2.7 S and a molecular weight of about 26,000. MCAF is derived from, and may be identical to the "A fragment" of cholera toxin. Generation of MCAF depends on prior interaction of cholera toxin with either dithiothreitol, NADH, NAD, or a low-molecular-weight component (less than 700 daltons) present in cytoplasm. Subsequent exposure of this pretreated cholera toxin to cell membranes from a variety of mouse ascites cancer cells is followed rapidly by the appearance of MCAF, which no longer requires dithiothreitol, NADH, or NAD for the activation of adenylate cyclase. Activation of adenylate cyclase by MCAF in ascites cancer cell membrane fragments is not reversed by repeated washing of these membrane fragments. Adenylate cyclase in normal cell membrane fragments fails to respond either to cholera toxin or MCAF in the presence of dithiothreitol. In striking contrast, the adenylate cyclase in membrane fragments from five ascites cancer cells responds to either MCAF or native cholera toxin preincubated with dithiothreitol, NADH, or NAD.


Amino-acid sequence of activation cleavage site in plasminogen: homology with "pro" part of prothrombin. A 38-residue fragment is isolated from carboxymethylated plasminogen. Residues 29-38 have the same sequence as the amino-terminal end of the light chain of plasmin. The sequence 1-28 is therefore the sequence of the carboxyl-terminal end of the heavy chain and contains the specific sequence at which urokinase (EC 3.4.99.26) and other plasminogen-activating serine proteases split. Two of the five carboxymethyl-cysteine residues in the isolated fragment are situated close to the cleavage site and the fragment is not itself a substrate for plasminogen-activators. Residues 1-11 show extensive sequence homology with residues 137-147 and 242-252 in prothrombin, which are located in corresponding regions of the two internally homologous 83-residue structures in the non-thrombin part of the molecule, indicating that such structures may be a common feature of the non-protease part of the larger serine protease zymogens.


Molecular orbital studies of enzyme activity: I: Charge relay system and tetrahedral intermediate in acylation of serine proteinases. The charge relay ststem and its role in the acylation of serine proteinases is studied using the partial retention of diatomic differential overlap (PRDDO) technique to perform approximate ab initio molecular orbital calculations on a model of the enzyme-substrate complex. The aspartate in the charge relay system is seen to act as the ultimate proton acceptor during the charging of the serine nucleophile. A projection of the potential energy surface is obtained in a subspace corresponding to this charge transfer and to the coupled motions of active site residues and the substrate. These results together with extended basis set results for cruder models suggest that a concerted transfer of protons from Ser-195 to His-57 and from His-57 to Asp-102 occurs with an energy barrier of 20-25 kcal/mole (84-105 kJ/mole). The subsequent nucleophilic attack on the scissile peptide linkage by the charged serine is then seen to proceed energetically downhill to the tetrahedral intermediate. The formation of the tetrahedral intermediate from the Michaelis complex is calculated to be nearly thermoneutral.


Methylation of messenger RNA of Newcastle disease virus in vitro by a virion-associated enzyme. Purified Newcastle disease virus contains an enzyme that incorporates the methyl group from S-adenosyl-L-methionine into RNA synthesized in vitro by the virion-associated RNA polymerase (RNA nucleotidyltransferase). Incorporation of radioactivity from S-adenosyl-L-[methyl-3H]methionine was totally dependent upon RNA synthesis. The methylation reaction was completely inhibited by S-adenosyl-L-homocysteine, suggesting the transfer of only the methyl group of S-adenosyl-methionine to RNA products. Velocity sedimentation and hybridization of the in vitro product RNA indicated that both [3H]methyl and [32P]GMP labels resided in single-stranded 18S RNA molecules which were virus specific. Approximately 1 to 2 methyl groups were incorporated per RNA molecule. DEAE-cellulose chromatography of product RNA after alkaline hydrolysis suggested that the 5' terminus was the site of methylation.


Isolation of a cationic polypeptide from human serum that stimulates proliferation of 3T3 cells. A basic polypeptide that stimulates DNA synthesis and cell division in confluent populations of mouse Balb/c-3T3 cells has been isolated from whole human serum, and has been separated from the heterogenous group of molecules with insulin-like activity. This highly purified basic polypeptide has a molecular weight of 1.3 x 10(4) and an isoelectric point of 9.7. Approximately 10(7) polypeptide molecules in the growth medium allow the replication of one density-inhibited cell.


Minimal requirements for template recognition by bacteriophage Qbeta replicase: approach to general RNA-dependent RNA synthesis. Any oligo- or polynucleotide able to offer a C-C-C-sequence at the 3'-terminus and a second C-C-C-sequence in a defined steric position to Qbeta replicase is an efficient template. Corresponding chemical modifications convert non-template RNAs to template RNAs.


Apparent dependence of interactions between cytochrome b5 and cytochrome b5 reductase upon translational diffusion in dimyristoyl lecithin liposomes. Dimyristoyl lecithin liposomes, containing cytochrome b5 reductase (NADH:ferricytochrome b5 oxidoreductase, EC 1.6.2.2) and varying amounts of cytochrome b5, were used to measure flavoprotein catalysis alone and catalysis requiring electron transfer between the reductase and cytochrome as a function of temperature. Whereas flavoprotein catalysis showed a simple linear temperature dependence in an Arrhenius plot, the reaction involving electron transfer between the two bound enzymes showed a marked, 4-fold, change in rate at the crystalline-liquid crystalline phase transition of the hydrocarbon chains of the lecithin vesicles and a second, minor change involving the minor transition. These data represent strong evidence that protein-protein interactions in this membrane model system are dependent upon translational diffusion of nonpolar segments of the proteins in the hydrocarbon region of the phospholipid bilayer.


Protein-water interaction studied by solvent 1H, 2H, and 17O magnetic relaxation. Previous studies of the magnetic field dependence of the magnetic relaxation rate of solvent protons in protein solutions have indicated that this dependence (called relaxation dispersion) is related to the rotational Brownian motion of the solute proteins. In particular, the dispersion of the longitudinal (spin-lattice) relaxation rate 1/T1 shows a monotonic decrease with increasing field, with an inflection point corresponding to a proton Larmor frequency which is inversely proportional to the orientational relaxation time of the protein. We have now compared the relaxation dispersion of solvent 1H, 2H, and 17O In aqueous solutions of lysozyme (molecular weight 14,700) and 1H and 2H in solutions of hemocyanin (molecular weight 14,7 00) and 1H and 2H in solutions of hemocyanin (molecular weight 9 x 10(6)). The main experimental observation is that the dispersion of the relaxation rates of the three solvent nuclei in lysozyme solutions, normalized to their respective rates in pure water, is essentially the same. This is also true for 1H and 2H relaxation in hemocyanin solutions. These results confirm that entire solvent water molecules, rather than exchanging protons, are involved in the interaction. We have been unable to deduce the correct mechanism to explain the data, but we can eliminate several interaction mechanisms from consideration. For example, all observations combined cannot be explained by a simple two-site model of exchange, in which water molecules are either in sites on the protein with a relaxation rate characteristic of these sites, or else in the bulk solvent (the observed relaxation rate being the weighted average of the two). Also eliminated is the class of models in which the protein molecules induce a preferential partial alignment of neighboring solvent molecules, for example by electrostatic interaction of the electric dipole moments of the water with the electric fields produced by surface charges of the protein molecules. In addition, the idea that relaxation of solvent nuclei is due, in the main, to interactions with protein protons is precluded. Rather, it appears that the protein molecules influence the dynamics of the motion of solvent water molecules in their neighborhood in a manner that imposes on all the solvent molecules a correlation time for their orientational relaxation which equals that of the solute proteins.


Hemoglobin synthesis in somatic cell hybrids: coexpression of mouse with human or chinese hamster globin genes in interspecific somatic cell hybrids of mouse erythroleukemia cells. Somatic cell hybrids were derived by fusion of mouse erythroleukemia cells with fractionated human marrow enriched in erythroblasts, or with chinese hamster fetal liver erythroid cells. Such interspecific hybrid cells, when isolated in suspension culture, had retained nearly all the mouse chromosomes and had lost most of the human or chinese hamster chromosomes. However, two such hybrids (one human, the other hamster) studied 4-6 weeks after fusion, were found to contain several non-mouse chromosomes. RNA extracted from the human marrow x erythroleukemia hybrid annealed equally to both human and mouse globin complementary DNA, indicating that coexpression of the globin genes of each species had occurred in the hybrid cells. Mouse and human mRNA were found to accumulate only after incubation of the cells in 2% dimethylsulfoxide. The chinese hamster x erythroleukemia hybrid appeared to contain a double complement of mouse chromosomes in addition to several chinese hamster chromosomes. After 7 days of incubation in 2% dimethylsulfoxide, [3H]leucine was incorporated into chinese hamster beta-globin and the mouse globin chains. Thus, globin genes from differentiated cells, when introduced into spontaneously proliferating erythroleukemia cells, may be expressed after exposure of the resulting hybrid cells to an agent capable of inducing hemoglobin synthesis in the erythroleukemia cell.


Chromatin architecture: investigation of a subunit of chromatin by dark field electron microscopy. Dark field scanning electron microscopy of unstained, unfixed samples of chromatin, histone-1-depleted chromatin, and nucleohistone has been used to identify an apparent subunit of chromatin, namely a disk-shaped structure we term the unit particle, which is probably about 135 A wide and 50 A thick in the hydrated state. The unit particles are found at rather uniform intervals along thin DNA-like fibers. Histone 1 depletion leads to a bimodal distribution of these spacings. Our observations suggest that the unit particle consists of a loop of nucleoprotein, perhaps around a histone core.


Association of high-molecular-weight proteins with microtubules and their role in microtubule assembly in vitro. High-molecular-weight components (HMW) specifically associated with microtubule protein purified from porcine brain tissue were separated from tubulin by DEAE-Sephadex ion exchange chromatography. Analysis by viscometry, sedimentation, and electron microscopy of the unfractionated microtubule protein, separated HMW and tubulin fractions, and reconstituted mixtures showed that HMW promoted formation of ring structures at 5 degrees and tubule polymerization at 37 degrees. The HMW reassociated with tubulin and was identified in thin sections as 18.9 x 5.6 nm projections attached to the microtubules with a longitudinal periodicity of 32.5 nm. These studies: (1) indicate that the HMW fraction stimulates microtubule assembly by facilitating the formation of ring structures which are apparently intermediates in polymerization, and (2) demonstrate that the HMW associates with microtubules as a structural component projecting from the surface of the microtubule wall.


Microfibril assembly by granules of chitin synthetase. Purified preparations of chitin synthetase (EC 2.4.1.16; UDP-2-acetamido-2-deoxy-D-glucose:chitin 4-beta-acetamidodeoxyglucosyltransferase), capable of forming microfibrils in vitro, were isolated from yeast cells of Mucor rouxii. Chitin synthetase was obtained either by substrate-induced liberation of bound enzyme (54,000 x g pellet) or by isolation of unbound enzyme present in the 54,000 x g supernatant of a cell-free extract. Both preparations contained ellipsoidal granules from about 350 to 1000 A diameter. Many granules exhibited a marked depression. No typical unit membrane profiles appeared in thin sections of glutaraldehyde/OsO4-fixed samples. Upon incubation with substrate and activators, chitin microfibrils were produced. The microfibrils were often found intimately associated with granules. The most common configurations were: a microfibril with a granule at one end, or two microfibrils "arising" from the same granule. These findings lend support to the granule hypothesis for the elaboration of cell wall microfibrils by end-synthesis.


Establishment of tight junctions between epithelial cells. Epithelia serve as barriers to the diffusion of solutes between body compartments, and must do so despite the frequent loss of cells. When single cells are experimentally removed from the Necturus gallbladder epithelium, contiguous cells migrate to fill the defect within 30 min. Electrophysiological measurements show that the local electrical resistance across the epithelium in the region of a wound returns to normal in the same period of time; electron microscopy demonstrates that tight junctions are formed concurrently. Physiologically functional and morphologically recognizable tight junctions can thus be established within 30 min, demonstrating a mechanism for the rapid restoration of epithelial integrity after cell loss.


Biosynthesis of delta-aminolevulinic acid from the intact carbon skeleton of glutamic acid in greening barley. The customary route in animals and bacteria for delta-aminolevulinic acid biosynthesis is from glycine and succinyl CoA, catalyzed by the enzyme delta-aminolevulinic acid synthetase [succinyl-CoA:glycine C-succinyltransferase (decarboxylating), EC 2.3.1.37]. Attempts to demonstrate this route in plants have been unsuccessful. Evidence is given for a new enzymic route of synthesis of delta-aminolevulinic acid in plants. This route involves the incorporation of the intact five-carbon skeleton of glutamic acid into delta-aminolevulinic acid. Demonstration of the new pathway in plants has been made by feeding specifically labeled [14C]glutamic acid to etiolated barley shoots greening in the light. In the presence of levulinate, a competitive inhibitor of delta-aminolevulinic acid dehydrastase [porphobilinogen synthase; delta-aminolevulinate hydro-lyase (adding delta-aminolevulinate and cyclizing); EC 4.2.1.24], delta-aminolevulinate accumulates. The delta-aminolevulinate formed was chemically degraded by periodate to formaldehyde and succinic acid. The C5 (formaldehyde) fragment was separated, as the 5,5-dimethyl-1,3-cyclohexanedione (dimedone) derivative, from the C1-C4 (succinic acid) fragment. The C5 atom contained radioactivity predominantly derived from C1 of glutamic acid. Conversely, the labeled C3 and C4 atoms of glutamic acid were found primarily in the succinic acid (C1-C4) fragment of delta-aminolevulinate. This labeling pattern for delta-aminolevulinic acid is consistent with a biosynthetic route utilizing the intact five-carbon skeleton of alpha-ketoglutarate, glutamate, or glutamine, and is inconsistent with the delta-aminolevulinic acid synthetase pathway utilizing glycine and succinyl CoA as precursors.


Myogenesis of avian striated muscle in vitro: role of collagen in myofiber formation. The complex chemical environment required for the development of the myofiber (myotube) from embryonic avian muscle myoblasts in vitro has been simplified. Myotube formation is shown to occur in the presence of insulin, a low-molecular-weight (fusion) factor obtained from embryo extract, and a collagen substratum. In the absence of collagen, globular structures are formed which are microscopically identical to the globular syncytial structures previously described [de la Haba and Amundsen (1972) Proc. Nat. Acad. Sci. USA 69, 1131-1135]. A high-molecular-weight fraction from embryo extract will also promote myotube formation in the presence of the fusion factor. This fraction is shown to contain (a) collagen, which promotes myotube formation, and (b) an additional factor which also promotes myotube formation, and which we tentatively hypothsize to be an inducer of collagen synthesis by myogenic cells.


Feedback dynamics analysis of secondary successional transients in ecosystems. A theoretical dynamic model of the mutual causalities that generate secondary successional behavior in ecological systems is developed using zero- and first-order nonlinear difference equations. The model is based on Odum's tabular model of ecological succession, and has been simulation-tested for the case of secondary succession in a grassland ecosystem. It shows how energy, abiotic and biotic matter, and community (species) diversity interact in time and space to produce autogenic succession, that is, developmental changes generated by biotic components within the system as distinguished from allogenic forcing functions from without the system. The simulations demonstrate that successional transients can arise from the endogenous feedback structure of the ecosystem and provide strong evidence for the validity of the model.


Interlocus variation of genetic distance and the neutral mutation theory. Theoretical distributions of genetic distance between reproductively isolated taxa are derived by means of computer simulation, taking into account mutation and random genetic drift. The distributions obtained are in good agreement with the observed distributions of interracial and interspecific genetic distances for enzymes loci in Drosophila. This indicates that the gene substitution at enzyme loci can be explained by the neutral mutation theory.


Distribution of allelic frequencies in a finite population under stepwise production of neutral alleles. A formula for the distribution of allelic frequencies in a finite population is derived assuming stepwise production of multiple alleles. Monte Carlo experiments were performed to check the validity of the formula, and excellent agreement was obtained between theoretical distribution and experimental results. The formula should be useful for analyzing genetic variability in natural populations that can be detected by electrophoretic methods.


Antigen-induced conformational changes in antibodies and their Fab fragments studied by circular polarization of fluorescence. Conformational changes induced in antibody molecules and in their Fab fragments by binding of antigen were investigated by the circular polarization of the fluorescence emitted by the tryptophan residues. This property of the fluorescence is related to the asymmetry, and thus to the conformation and environment, of the emitting chromophore. Changes in the circular polarization of the fluorescence of the antibody were observed upon binding of RNase to anti-RNase, of poly(DL-alanyl)-poly(L-lysine) to antipoly(D-alanine), and of the "loop" of lysozyme, a monovalent antigenic determinant, to anti"loop." The spectral changes were observed at different antigen-antibody ratios, including high antigen excess, indicating that they are due to antigen binding and not to aggregation. The circular polarization of fluorescence also detects changes in conformation of the different Fab fragments upon binding of the corresponding antigens. These changes in conformation were, however, markedly different from those observed for the whole antibody molecules, and indicated an interaction between the Fc and Fab fragments in the antibody molecule, and probably a change in the conformation of Fc upon binding of antigen to the antibody. In contrast, the small hapten, phosphorylcholine, did not induce a change in the circular polarization of the fluorescence of its antibody or corresponding Fab fragments. Reduction of the interchain disulfide bonds of the antibodies abolished the antigen-induced spectral changes due to the presence of the Fc portion in the molecule, but not the changes observed in Fab, suggesting that the disulfide bonds at the hinge region of the antibody are required for the transmission of the conformational change from the Fab to the Fc.


Lysis of leukemia cells by spleen cells of normal mice. Spleen cells from 2- to 3-month-old normal mice of some strains having a low incidence of spontaneous leukemia were found to lyse cells of the spontaneous AKR leukemia K36 in the 51Cr release assay. Incubation of 51Cr-labeled ADR K36 cells with spleen cells from normal C57BL/6, C57L, C57BL/10, and RF mice resulted in the release of significantly more 51Cr than that released in the presence of medium alone. In contrast, 51Cr released from AKR K36 cells after incubation with spleen cells from mice of the high leukemic strains AKR and C58 was less than that released spontaneously. The results of competitive inhibition tests when C57BL/6 spleen cells were incubated simultaneously with 51Cr-labeled AKR K36 target cells and varying numbers of nonlabeled cells demonstrated that the cytotoxic activity of normal C57BL/6 spleen cells was directed against an antigen(s) associated with several leukemias, but that was undetectable on normal thymocytes. Pretreatment of C57BL/6 spleen cells with carbonyl iron and a magnet, which removed phagocytic macrophages, did not decrease the cytotoxic acitivity for AKR K36 cells.


Interaction of lymphocytes with lipid bilayer membranes: a model for lymphocyte-mediated lysis of target cells. Horizontal lipid bilayer membranes were used as a model system to study lymphocyte-mediated killing of target cells. Dinitrophenylated lipid bilayers can physically support dozens of lymphocytes for periods of over one hour without breakage or increasing the electrical conductance of the membrane. However, in the presence of antibody against Dnp, human lymphocytes rapidly induced increases in membrane conductance of several orders of magnitude without membrane breakage. Such ionic permeability increases occurred only when the membrane voluage was positive on the lymphocyte side, as would be the case with a target cell membrane. The lymphocyte and antibody dependence of this conductance increase parallels that observed for lymphocyte killing of antibody-coated target cells. The results are interpreted as evidence that the primary event in lymphocyte killing of antibody-coated target cells is the creation of ion-conducting channels in the target membrane.


Methylmalonicacidemia: biochemical heterogeneity in defects of 5'-deoxyadenosylcobalamin synthesis. We measured the synthesis of 5'-deoxyadenosylcobalamin (AdoCbl) in fibroblast extracts from patients with inherited methylmalonicacidemia due to deficient activity of the cobalamin-dependent holoenzyme, methylmalonyl-CoA mutase (EC 5.4.99.2). Previous studies with intact fibroblasts from patients whose holoenzyme deficiency was secondary to abnormal cobalamin metabolism had defined two phenotypes, one in which whole cells failed to accumulate AdoCbl and a second in which they failed to accumulate both AdoCbl and the second cobalamin coenzyme, methylcobalamin. With a broken cell assay of AdoCbl synthesis in cell extracts and the cell lines are named cbl A mutants; the other class shows severe deficiency of AdoCbl synthesis and the cell lines are named cbl B mutants. We define cbl C mutants as those in which both AdoCbl and methylcobalamin fail to accumulate in intact cells. The assay for AdoCbl synthesis is thought to measure two enzymatic activities, cob(II)alamin reductase (EC 1.6.99.9) and cob(I)alamin adenosyltransferase (EC 2.5.1.17). Subcellular fractionation studies place this combined activity in mitochondria.


Fetal mouse hearts: a model for studying ischemia. A new experimental model for the study of two important aspects of ischemia, namely, oxygen and substrate deprivation, is proposed: the intact, beating fetal mouse heart in organ culture. This model offers long-term stability, ease and reproducibility of preparation, and the ability to manipulate experimental conditions. Hearts deprived of oxygen and glucose ceased beating immediately. After 3-4 hr of deprivation, biochemical and ultrastructural changes consistent with ischemic injury were evident. These include depletion of ATP and glycogen levels, loss of cytoplasmic enzymes, and extensive swelling and disruption of mitochondrial structure. Glucose and insulin partially protected against ATP depletion. Upon resupply of oxygen and glucose , beating resumed immediately, ATP levels rapidly increased to control levels and, consistent with this, mitochondrial structure returned toward normal. During the recovery phase autophagic vacuoles containing damaged mitochondria and myofibrils were seen, indicating that repair mechanisms were activated. Consistent with this, the proportion of lysosomal enzymes that were present in the nonsedimentable fraction of the tissue homogenate increased. We conclude that the cultured fetal mouse heart is a model useful for studying myocardial responses to anoxia and/or substrate deprivation and for assessing interventions designed to limit damage or to stimulate repair after ischemic injury.


Ontogenesis of a biological clock for serotonin:acetyl coenzyme A N-acetyltransferase in pineal gland of rat. Serotonin:acetyl coenzyme A N-acetyltransferase (EC 2.3.1.5) Activity in pineal gland was assayed in rats which were born and raised under diurnal lighting conditions, in continuous darkness, or in constant light. N-Acetyltransferase activity in the pups raised under diurnal lighting showed a rhythmic pattern, with high enzyme activity during dark period. The pups raised in continuous darkness also showed a rhythmic pattern, the phase of which was delayed by 8 hr in 7-week-old pups; the rhythmic phase of N-acetyltransferase began in the evening in 12-day-old pups and was regularly delayed by 1 hr every week. The pups raised in constant illumination also showed a rhythmic pattern; the rhythmic phase was delayed by 3 hr every week. When the mother rats were coupled in darkness and maintained in darkness during pregnancy and after the pups were born, their pups again showed a rhythmic pattern. These observations indicate that the biological clock for N-acetyltransferase is generated independently of environmental lighting. When mothers were coupled under reversed lighting conditions and transferred into darkness or light, the rhythmic pattern in their pups was inverted 180 degrees from that of pups born of diurnal mothers. When the pups were raised in darkness, the rhythmic phase of N-acetyltransferase in the pups was similar to that of their mothers. It is suggested that in the absence of light-darkness cycle, the mother rat sets the rhythm of the pups to synchronize with her own rhythm. When pups were reared by a foster mother with a different rhythmic pattern from that of their original mother, the rhythmic phase in the pups was closer to that of the original mother, suggesting that the original mother plays the predominant role setting the rhythm of the pups.


Individual odor differences and their social functions in insects. The evolution of individual or subgroup differences in odors of halictine bees is suggested from possible widespread intraspecific variation in pheromones. An important result of such variation may be maintenance of genetic polymorphisms; in nesting Hymenoptera odor differences may also facilitate individual nest recognition. In Lasioglosum zephyrum males habituate to odors of different females and perhaps thus save time by not trying to copulate with nonreceptive individuals. Guards (females) at nest entrances distinguish their few nestmates (other females) from other conspecific individuals by odors, seemingly pheromones. Duration of the habituation in L. zephyrum is at least an hour (perhaps much more) for males in relation to females and 6 or 7 days for guards in relation to nestmates. Studies of pheromones should take into consideration the possibility of pheromonal polymorphism in any species and the likelihood that it may be significant from biological and practical viewpoints.


Slow growth rate of a deep-sea clam determined by 228Ra chronology. The age of a deep-sea clam, Tindaria callistiformis, from 3803 m depth has been determined by 228Ra (6.7 year half-life) chronology of separated size fractions of a captured population. A length of 8.4 mm is attained in about 100 years. Shells of this size fraction show about 100 regularly spaced bands, indicating that the growth feature may be an annual one.


Glycogen metabolism in human skin fibroblasts. Influence of maltose on the activity of acid alpha-1, 4-glucosidase. Maltose added to medium in a concentration of 100 mg/100 ml enhances the hydrolytic activity of acid alpha-1, 4-glucosidase in skin fibroblasts in culture derived from normal human subjects, but under the same conditions maltose has no demostrable effect on the enzyme in fibroblasts derived from skin of patients with Cori Type II glycogenosis. Upon addition of maltose to Cori Type II fibroblasts there is a marked decrease of glucose in medium overlying the cells with a concomitant marked increase in glycogen content of the same cells. Glycogen decreases in a similar manner in both normal and mutant cell types after 16 days in culture. This apparent utilization or degradation of glycogen in Cori Type II fibroblasts in culture is difficult to explain unless only a proportion of the polysaccharide accumulates within lysosomes. We propose, therefore, that extra-lysosomal glycogen which accumulates in fibroblasts from Cori Type II glycogenosis may be more easily degraded by glycogenolytic cytoplasmic enzymes, particularly in cells grown for as long as 2 wk in glucose-starved media.


An effect of chlorhexidine and two related drugs on glycosaminoglycans in rat skin. The aim of the present investigation was to estimate the local effect of three plaque-inhibiting drugs on some glycosaminoglycans in rat skin. The drugs comprised chlorhexidine, dichlorhexidine, and trichlorhexidine; and the glycosaminoglycans examined were hyaluronic acid, chondroitin sulfate, and heparin. Glycosaminoglycans were measured by the carbazole method. Upon subcutaneous injections in rats, chlorhexidine, dichlorhexidine, and trichlorhexidine caused marked reductions in the surrounding skin's content of total hexosamine as well as of the three types of glycosaminoglycans. No significant difference could be demonstrated between the different types of glycosaminoglycans in this respect.


The effectiveness of a synthetic vasopressin analogue as a vasoconstrictor. The effectiveness of a synthetis vassopressin analogue, ornithine-8-vasopressin (POR-8), as a vasocontrictor was tested in the superficial vessels of the rabbit ear. When compared to a control of normal saline and a standard of a dilute solution of epinephrine in lidocaine, POR-8 in saline is more effective than POR-8 in lidocaine, and is comparable in its effectiveness to the epinephrine solution.


Chromosome constitution of cells from human gingiva. This is a study of cells and chromosomes during serial transfer of tissue cultures, starting from the first mitosis occurring before explantation of normal gingival tissues and continuing until a genotypic variation was attained after explantation. From 16 specimens, 9 could be maintained in vitro for varying lengths of time, 7 for more than 50 weeks. In all cases, at 2 months in cultures and afterward, cells were found to be fibroblast-like cells with heteroploid chromosomal complement. The heteroploidy of the cells was due to extrasomy of chromosomes from all groups. However, chromosomes of the  me cells before culturing showed the normal diploid number of 46 chromosomes.


The parakeratin layer of zinc-deficient rat buccal epithelial. Weanling rats were fed a zinc-deificient diet, 1.3 ppm zinc, for four weeks. Parakeratotic changes of the buccal epithelium were studied by electron microscopy. The incomplete disintegration of the nucleus and cytoplasmic organelles in the horny layer is deemed to be due to insufficient function of zinc-related lytic enzymes.


Emotional factors in juvenile diabetes mellitus: a study of the early life experiences of eight diabetic children. The developmental history of eight diabetic children was compared with that of their nondiabetic siblings. On the basis of data obtained through interviews with the children and their families, as well as a chart review, we advance the hypothesis that an as yet unspecified metabolic "pre-diabetic" pathophysiological condition may be reflected in disturbances of appetite, satiation and weight regulation appearing early in life in those children who may later develop clinical diabetes mellitus. We further hypothesize that these dysfunctions are accompanied by a disturbance in important psychological developmental processes, compounding the liability a physiologically susceptible individual suffers. The results are discussed in terms of previous psychosomatic research.


[Rotation myoplasty using the sternocleidomastoid muscle, together with hemimandibulectomy]. Rotation myoplasty using the sternomastoid muscle in association with hemi-mandibulectomy would appear to be of value for two reasons:--functional, strengthening the wall of the buccal cavity and providing a contour capable of containing the prosthesis, following fibrous transformation of the muscle,--plastic, restoring the aesthetic symmetry of the lower half of the face.


A morphologic description of a dry skull with mandibulofacial dysostosis. The morphology of an East Indian, dry skull exhibiting the characteristics of mandibulofacial dysostosis (MFD) is described. The skull was small, but the shape of the calvarium was essentially normal. Extensive anomalies were registered in the sphenoid bone, the temporal bone, the zygomatic bone, the maxilla, and the mandible. A lateral cephalometric radiograph of the skull was compared with a mean value diagram of adult Danish males in order to illustrate the morphologic aberrations of the MFD skull. The etiology and pathogenesis of the syndrome are disucssed.