Heat treatment of cobalt-chromium alloy wire. This study shows that the ability of cobalt-chromium wire to resist permanent deformation is definitely affected by the temperature of heat treatment. For each temperature of heat treatment up to 1200 degrees F there is progressively greater resistance to permanent deformation; at temperatures of heat treatment above 1200 degrees F, however, there is a rapid decline in resistance to permanent deformation due to partial annealing. The maximum resistance to permanent deformation occurs from heat treatment in the temperature range of 1100 degrees to 1200 degrees F. A clinician desiring maximum resistance to permanent deformation from a .016 inches x .022 inches cobalt-chromium archwire should heat-treat the wire at 1100 degrees to 1200 degrees F for 5 minutes in a dental furnace. If the wire was in a highly work-hardened condition as were the wire specimens of this study, he could expect an increase in resistance to permanent deformation of approximately 174 percent. Heat treatment at lower temperatures could be used in situations requiring less than maximum resistance to permanent deformation. Heat treatment at 900 degrees F would give approximately a 95 percent increase in resistance to permanent deformation. Of course, heat treatment would not be indicated when the desired level of resistance to permanent deformation was not greater than the amount exhibited in the untreated wires of this study. When an electrical resistance heat-treatment unit and 950 degrees F temper-indicating paste were used, the clinician would expect increased resistance to permanent deformation similar to that seen in the wires heat-treated with a dental furnace at 800 degrees and 900 degrees F, i.e., about half of that obtained by the 1200 degrees F treatment. This study has determined the effects that various temperatures of heat treatment have on the resistance to permanent deformation of cobalt-chromium wire specimens which were formed into a specific pattern of loops. The following conclusions can be drawn from the results of this investigation: 1. Heat treatment at 1200 degrees F gives the maximum resistance to permanent deformation to .016 inches x .022 inches cobalt-chromium wire. 2. Increases in resistance to permanent deformation of approximately 95 percent and 174 percent may be expected from heat treatment of .016 inches x .022 inches cobalt-chrome wire at 900 degrees and 1200 degrees, respectively. 3. Wires, heat-treated with an electrical resistance unit using 950 degrees F temper-indicating paste, exhibit increases in resistance to permanent deformation similar to wires heat-treated in a dental furnace at 800 degrees and 900 degrees F.


Orthodontic elastic materials.

Orthodontic elastic materials. Latex elastics and synthetic elastomers have certain similarities and differences. In the fracture tests the latex elastics showed a greater amount of loss in strength than plastic elastomers when stretched over a 21 day period. There is a great variability, as much as 50%, in the tensile strength of the plastic materials taken from the same batch and stretched under the same conditions. The Ormco Power Chain was more resilient than the Unitek AlastiK chain. The Unitek AlastiKs had more force and stretched less. The force decay of synthetic elastomers, stretched over a specific length and time, exhibited a great loss in force. This loss could be as great as 73% during the first day. The decay of force continued at a slower rate during the rest of the 21 day period. Unitek AlastiK C2 double links, when stretched 17 millimeters, had a higher initial force averaging 641 grams (22.5 ounces) than the Ormco Power Chain which averages 342 grams (12.0 ounces). In one day the force was reduced to 171 grams (6.0 ounces) for both materials. The elastic materials within the same batch showed a great variation in the modulus of elasticity under different test conditions. The approximate force generated when stretched dry, within the elastic limit, was 22 grams per millimeter for 3/16 inches heavy latex elastics. The Unitek AlastiK C2 gave a force of 89 grams per millimeter, while the Ormco Power Chain had a value of 46 grams per millimeter. The modulus of elasticity of all of the materials was much lower after immersion in the water bath. The force decay under constant force application to latex, elastic, polymer chains, and tied loops showed that the greatest amount of force decay occurred during the first three hours in the water bath. The forces remained relatively the same throughout the rest of the test period. The elastic materials undergo permanent deformation in shape. The synthetic elastomers exhibited plastic deformation when the elastomers were stretched 17 millimeters for 21 days. In the dry condition the force decay was 63% for the Unitek chains and 42% for the Ormco Power Chain. The synthetic elastomers should be prestretched before being placed in the mouth. The elastomers should be used within their resilient ranges. Clinical treatment procedures should take into consideration the rapid initial force decay of elastic materials that occurs during the first day and the residual forces remaining.


Relationship of occlusion and periodontal disease: part IX-incisor inclination and periodontal status. In this study population the following observations have been made: Periodontal destruction, gingival inflammation and mobility were not significantly related to axial inclination of the incisor teeth. Labial gingival recession of the mandibular incisor was related to linguoversion (less than 85 degrees to GoGn). No other associations between incisor inclination and labial or lingual recession were found. Age was not related to either maxillary or mandibular incisor inclination. The periodontal-incisor inclination relationships reported above for periodontal destruction and gingival inflammation were not altered by the factor of age. Study of the secondary influence of incisor inclination on the relationships of selected occlusal factors and periodontal pathosis showed: A. Severe overjet (more than 6mm) had been found to be associated with more periodontal destruction. With severe overjet maxillary incisors in linguoversion (less than 100 degrees to SN) were somewhat healthier than all others. Among the same cases of severe overjet mandibular incisors in labioversion had slightly more disease than all others. B. The absence of a significant correlation between anterior overbite or crowding reported previously was not influenced by incisor inclination. C. Facial alveolar bone thickness, observed clinically, was studied for its relation to periodontal destruction and gingival inflammation. Thick facial alveolar bone was found to be associated with increased pathosis. This finding was not consistent for the maxillary and mandibular incisor and the influence of other factors might be suspected: Incisor inclination had no effect on the bone thickness-periodontal disease findings.


Measurement of the cell migration index with a HeNe laser. Human diploid fibroblasts (WI38) were inoculated into Rose multipurpose culture chambers, using a high population density to develop confluency. After 24 hours, cells from a 1 mm swath were scraped from the center of the chamber. This cleared path was positioned to permit an unobstructed transmission of a 0.9 X 20 mm beam of light from a 1 mW HeNe laser. As cells migrated, at 37 degrees C, into the path of the laser beam the light scatter was recorded, using a photomultiplier tube. Because the amount of light scatter was proportional to the number of cells migrating into the beam, the system measured the migration index of the cells. Slight variations in the design of this device could facilitate data collection during surveys of toxic agents, fertility tests, and delayed hypersensitivity.


Current laser surgery.

Current laser surgery. With the development of a suitable apparatus sufficient experience has been accumulated in clinical surgery to enable one to reach the conclusion that the CO2 laser has an application in all branches of surgery without exception, whereas it has a decided advantage over other modalities in (1) All operations where the anticipated blood loss is significant. (2) Operations performed on or through infected tissue. (3) Extirpation of malignant tumors. (4) Cavitational surgery involving the use of an endoscope or microscope.


Laser surgery in otolaryngology: interaction of CO2 laser and soft tissue. The sequence of histological change induced by CO2 laser irradiation was discussed in terms of two factors: the physiomechanical factor and the physiochemical factor. At sufficiently high heat energy levels, the immediate findings are characterized by crater formation resulting from rapid vaporization of the water and ejection of the solid component. In the immediate vicinity of the crater edge, the maximum tissue temperature rise is 65 degrees C above the 32 degrees C ambient tissue temperature and it decreases to the primary tissue temperature within a distance of 2 mm. The healing process of CO2 laser induced lesions proceeds with minimal delay. The lymphatic and vascular channels are occluded in the marginal area of coagulation resulting in a marked hemostatic effect. This sealing effect increases the margin of safety in preventing possible dissemination of tumor cells. By selecting the appropriate power, time, and focus cone angle, precise destruction of preselected areas of tissue can be achieved with an extraordinary hemostatic effect without damaging the underlying tissue. These advantages are especially helpful in function-preserving surgery.


Tracheal injury following prolonged intubation. Prolonged respiratory assistance by positive pressure ventilation via cuffed tracheostomy or endotracheal tube can be complicated by mucosal erosions, tracheal stenosis, tracheomalacia, excavation of the tracheal wall with loss of tissue and tracheoesophageal fistula. Stenosis can occur at the subglottic region, at the stoma, or at the cuff site, whereas the other complications occur most often at the cuff site. This paper is concerned with complications occurring below the first tracheal ring.


Peptic stricture of the oesophagus: the role of oesophagogastrostomy. Sixteen patients with severe peptic stricture of the oesophagus were treated by oesophagogastrostomy at the Royal Children's Hospital, Melbourne, during the period 1948 to 1968. It has been possible to obtain a follow up on all patients, so that the period of follow up has varied from seven to 24 years. Although the early postoperative results were promising, later problems occurred in over half of the patients, the major complication being recurrence of peptic stricture at the anastomotic site.


A device for surface cooling and rewarming in operations on the "dry" heart in babies and children during moderate, deep and profound hypothermia. Following a clinical experience of 100 cardiac operation in infants durind deep hypothermia, as low as 15C, the authors have designed a new bath for the procedure which incorporates several improvements over those used previously. The device described allows continuous cooling or rewarming of the patient at any stage of the operation by addition of more cold or hot water as required. It is possible to operate with the patient prone or on the side at any level of hypothermia, and while using heart lung bypass. The construction facilitates the even distribution of the circulating water, and a thermostatic control allows the temperature to be fixed at any level required.


Splenectomy: a review of morbidity.

Splenectomy: a review of morbidity. One hundred and fifty consecutive splenectomies, performed at the Royal Prince Alfred Hospital over a five-year period beginning in 1968, have been reviewed in a retrospective study. Splenectomy incidental to some other resectional procedure in the upper abdomen carried a mortality of 17%, accidental injury to the spleen during upper abdominal surgery carried a mortality of 28%, external trauma to the spleen a 7% mortality, while splenectomy for the diagnosis or therapy of a haematological disorder carried the lowest mortality, namely 4%. Morbidity and mortality were related to the age of the patient, and the mortality among patients 60 years or more was 26%. Pulmonary complications (excluding pulmonary embolus) occurred in 48% of patients. Clinically evident thromboembolism was detected in 10.7% of patients. A definite relationship to platelet counts of more than 500,000/mm3 was noted amongst patients who were not heparinized. Splenectomy is associated with a high morbidity and a significant mortality. Surgeons performing the operation and physicians referring patients for splenectomy need to be aware of the risks involved. Careful patient selection, scrupulous perioperative management, and meticulous surgery may reduce both morbidity and mortality. Elective splenectomy should be managed by a team of surgeons and physicians with a specific interest in the problems involved.


Benign osteoblastoma.

Benign osteoblastoma. Benign osteoblastoma is a benign bone-forming lesion, seen most commonly in the first three decades of life and having a predilection for the vertebral column and the short limb bones. It is distinguishable from osteoid osteoma on the bases of size (being more than one centimetre in diameter) and the absence of surrounding sclerosis. The two lesions, however, are probably of the same origin and behave differently because of their different situations. Treatment is by operation, either excision in whole if practicable, or thorough piecemeal excision and curettage, with bone grafting of the defect if indicated.


Synovial chondromatosis of the shoulder. Articular synovial chondromatosis is a rare disease commonly affecting the knee, hip or elbow, and characterized by the formation of metaplastic cartilaginous foci in the synovium. A case of cynovial chondromatosis affecting the shoulder joint is now reported because of the extreme rarity of the disease in this situation.


Clostridial infection in total hip joint replacement: a report of two cases. Two cases of clostridial cellulitis are presented in patients who had Charnley total hip joint replacement for severe osteoarthritis. Early deep infection can be a major problem in this operation, and is usually due to Staphylococcus aureus.


The place of ileorectal anastomosis in Crohn's disease. A study of 41 patients who underwent ileorectal anastomosis for Crohn's disease has shown this operation to be a relatively safe procedure with an immediate mortality of 2.5%. A defunctioning ileostomy may protect the patient against the consequences of anastomotic leakage. Ileorectal anastomosis is associated with a high early recurrence rate and on overall failure rate of up to 50% because of recurrence, intractable diarrhoea and exacerbation of perianal disease. However, half of the patients are able to retain the anastomosis and be restored to long-standing good health. The surgical philosophy in this Centre has largely evolved from treatment of small-bowel Crohn's disease, that is, resection of only the worst areas of involvement with the aim of symptomatic relief, and the results shown by this survey encourage us to pursue this policy by using ileorectal anastomosis for diffuse colonic disease, particularly if the rectum is uninvolved.


Hernia through the foramen of Winslow.

Hernia through the foramen of Winslow. This is a report of a hernia through the foramen of Winslow in which the right half of the colon was herniated. It was gangrenous and perforated. Following hemicolectomy the patient recovered.


Tropical intussusception in adults.

Tropical intussusception in adults. In contrast with the incidence in Britain and the United States, about 50% of intussusceptions in Sri Lanka occur in adults, the maximum age incidence being in the fourth decade. Seventy-six cases of intussusception in adults are analysed in this paper, 62 of which were of the caecocolic type, which though only rarely described in the West, have also been frequently reported from other tropical countries. The clinical picture was characteristic, and a mass was palpable in 90% of the patients, facilitating diagnosis without ancillary investigations. On the basis of the histological examination of resected specimens it is concluded that amoebic granulomatous formation in the dependent "diverticulum" of the caecum is the predisposing cause of the caecocolic intussusception, accounting for the chronicity of a large number of cases. Irrespective of the duration of the illness, gangrene did not occur in any of the cases if this type, although resection was occasionally required on account of irreducibility. In view of the proliferation of fibrous tissue in the wall of the caecum, complete evagination of the intussusception can only be achieved by surgical exploration and manipulation, the results of which are excellent.


Ischaemic ileal necrosis and carcinoid tumour. A case of ischaemic ileal necrosis is reported. It was associated with elastic vascular sclerosis produced by mesenteric metastases of an ileal carcinoid tumour.


One-stage repair of distal hypospadias.

One-stage repair of distal hypospadias. This paper reviews a short series of patients with distal hypospadias who were treated by Mustarde's one-stage technique, to which we have added a minor modification by tubing the flap before penis tunnelization. A single-stage repair has obvious advantages over a more conventional multistage procedure. The advantage of tubing the flap is early healing, and it reduces the risk of fistula formation, even in the presence of infection, which is very common in this country. The new urethral opening is situated at the fossa navicularis, and the functional results are excellent.


Haemangiomatous malformation of the orbito-sphenoidal region: cure by radiotherapy. This case was previously reported in 1973 at the 46th annual general scientific meeting of this College. Following a suggestion made at the meeting the patient was referred for radiotherapy, with a result so satisfactory as to call for a restatement of the case.


Pineal tumours: a clinical study of 23 cases. A series of 23 cases of pineal tumours is presented, and their salient clinical features are analysed. The rationale of the present trend of treatment is discussed, and the relevant literature is reviewed.


Retroperitoneal liposarcoma.

Retroperitoneal liposarcoma. The diagnosis of retroperitoneal fatty tumour is not extremely difficult provided that the possibility of its presence is kept in mind by the surgeon in all cases of distended abdomen in an apparently well-nourished patient. A careful clinical examination and a good excretory pyelogram are very important in the diagnosis. Surgical excision requires a considerable amount of patience and boldness on the part of the surgeon and is always gratifying, even if the tumour cannot be totally removed. Three cases of retroperitoneal tumour treated by us are presented. All three had had previous unsatisfactory treatment, the first two being incorrectly diagnosed and the third being inadequately excised. The pathology, diagnosis and treatment of these tumours are briefly discussed.


Perianal vaccinia: a case report.

Perianal vaccinia: a case report. Accidental perianal vaccinia is a rare condition, presenting acutely with severe pain and characteristic superficial ulceration. There is no specific treatment, and complete resolution occurs. A case is described of autogenous perianal vaccinia occurring in an adult.


A neck incision.

A neck incision. A "hockey stick" neck incision is recommended for laryngectomy with neck dissection, especially when the surgery follows radiotherapy.


The detection of serological factors in acute ulcerative colitis indicating a favourable short-term prognosis. Large-intestinal epithelial cells were obtained from operation specimens and by biopsy at sigmoidoscopy from 16 patients with acute severe mucosal ulcerative colitis and II control subjects with normal large-bowel mucosa. The ability of lymphocytes to release 51Cr label from large-intestinal epithelial cells was quantitatively assessed as percentage lymphocyte activity. The mean +/- standard deviation of percentage lymphocyte activity in 16 patients with acute ulcerative colitis on admission to hospital (88 +/- 8) was significantly greater than that in II normal subjects (16 +/- 8) (P is less than 0.01). In each study, samples of autologous serum were added to two reactions between lymphocytes and autologous large-intestinal epithelial cells. The results in the seven patients who came to urgent colectomy differed significantly from those in the nine who responded to corticosteroids. The mean +/- S.D. of percentage serological inhibition of lymphocyte activity in the group coming to colectomy was 44 +/- 16, and in those responding to steroids 12 +/- 5. When the serum of these patients was studied for immunofluorescent autoantibodies to normal human colonic mucosa, none of the seven patients treated by colectomy had detectable autoantibodies, in contrast with three of the nine patients with a more favourable short-term prognosis, in that they responded to steroid treatment.


Experimental coronary occlusion in calves: the effect of hyperglycaemia on ventricular fibrillation threshold. Measurements of ventricular fibrillation threshold (VFT) were made in two groups of bovine calves, each weighing 25 to 30 kg, before and after ligation of the anterior descending branch of the coronary artery. In the control group, the VFT was determined before occlusion of the anterior descending coronary artery, and the observations were repeated at 20-minute intervals after occlusion. A 33% reduction in VFT was observed 20 minutes after the occlusion. Prior loading with glucose by infusion of 100 ml of 10% glucose prevented the significant fall in VFT.


Response of remission lymphocytes to autochthonous leukaemic myeloblasts. Thymidine incorporation in vitro by remission lymphocytes from a total of 6 patients with acute myeloid leukaemia (AML) was measured following stimulation by autochthonous and allogeneic AML blasts and cell lines. The early peak response to autochthonous blasts in 2 of these patients (48-72 h) is consistent with the concept of a population of lymphocytes pre-immunized to antigens carried by the blasts. Although stimulation in one patient was increased in the presence of more stimulating (S) blasts than responding (R) lymphocytes, positive responses in other tests were obtained at an S : R ratio of 1 : 1-5. When different methods of treatment of the stimulating autochthonous blasts were compared with untreated cells, mitomycin C gave the highest stimulation indices 2 out of 3 tests. Tissue culture medium in which autochthonous blasts had been incubated for 3-5 days failed to stimulate either remission lymphocytes alone, or combined cultures of lymphocytes with autochthonous or allogeneic blasts, suggesting that mitogenic factors released from autochthonous blasts are not responsible for lymphocyte stimulation. Treatment of autochthonous or allogeneic AML blasts with glycine-HC1(pH 3-0) to remove putative "blocking" factors failed to increase the stimulatory capacity of the leukaemic blasts.


Trapping and destruction of blood-borne syngeneic leukaemia cells in lung, liver and spleen of normal and leukaemic rats. Leukaemic cells from rats with a lymphoid (HRL) or myeloid (SAL) leukaemia were labelled with 125IUDR and injected i.v. into either normal or leukaemic syngeneic recipients. The fate of the injected cells was studied in terms of the radioactivity in various tissues at various times up to 24 h later. In normal animals the leukaemia cells were destroyed rapidly in the reticulo-endothelial (RE) system; immediately after injection most recoverable activity was in the lung, with smaller amounts in the blood, spleen and liver but by 24 h only 20-30% of the injected activity could be recovered. In leukaemic recipients with high numbers of blasts in the blood the amount of activity recoverable from the lungs and bone-marrow was markedly reduced, while that in the blood was doubled. Nonetheless, the overall rate at which radioactivity was eliminated was not significantly different from that found in normal rats, in spite of the fact that the RE system was extensively infiltrated by leukaemia cells.


Nuclear DNA-polymerase estimation in human leukaemic myeloblasts. A technique which detects the presence of DNA-polymerase in cell nuclei by measuring the incorporation of 3H-thymidine-5-triphosphate (3H-TTP) has been used to estimate the proportion of leukaemic myeloblasts which contains DNA-polymerase and DNA capable of acting as primer-template. In six cases of previously untreated acute myeloid leukaemia the 3H-TTP labelling index (3H-TTP LI) was much larger than the fraction in DNA synthesis. After a single 'flash' injection of cytosine arabinoside a pronounced decline was observed in the 3H-TTP LI, which can be explained by a direct inhibition of NDA-polymerase. No change was observed in the fraction of cells labelled with 3H-thymidine. A decrease in 3H-TTP LI was also observed after a single i.v. dose of methotrexate.


Chemotherapy of the blastic phase of chronic granulocytic leukemia: hypodiploidy and response to therapy. Thirty-two patients in the blastic phase of Philadelphia chromosome-positive chronic granulocytic leukemia (CGL) were studied in a prospective randomized trial in which vincristine--prednisone (19 patients) was compared with cytosine arabinoside--6-thioguanine (13 patients). Seven remissions (37%), including two complete remissions, were achieved in the vincristine--prednisone group. Three of the five with predominant hypodiploid blast cell lines treated with vincristine--prednisone had complete or partial remissions. Both complete remitters presented with hypodiploidy consisting of 44 chromosomes. Four patients (30%) who were treated with cytosine arabinoside--6-thioguanine responded with one complete remission. The median survival of the responders was 8 mo, as compared to 1--2 mo for the nonresponders. Crossover to the opposite regimen as secondary therapy following refractoriness or resistance resulted in only 3 partial responses out of 21 treated. All three had previously responded to vincristine--prednisone. Of the 32 cases, 14 had an elective splenectomy during the chronic phase of the disease. Prior splenectomy did not influence the response to chemotherapy, as all three complete remitters occurred in the nonsplenectomized group. Similarly, survival in the blastic phase was not affected by prior splenectomy.


Ultrastructure of chronic megakaryocytic-granulocytic myelosis. To study chronic megakaryocytic-granulocytic myelosis, bone marrow biopsies from 5 patients were obtained. Ultrastructural quantitative and qualitative assessments demonstrate proliferation of both the megakaryocytic and granulocytic cell lines. Factors indicative of malignant growth in megakaryocytes included atypical maturation, nuclear-cytoplasmic asynchrony, nuclear inclusions and production of micromegakaryocytes. Abnormal thrombocyte delineation provoked giant platelet production. The neutrophil series also presented atypia as generally observed in chronic myelogenous leukemia. Even in cases without evidence of myelofibrosis under the light microscope, megakaryoblasts were associated with fibrillar structures. These cells may be responsible for the initial step in fibrillogenesis by providing a medium conductive to the collagen formation found in later stages of this disease.


Six cases of Gilles de la Tourette's syndrome. Six cases of Gilles de la Tourette's syndrome are discussed in the light of conflicting views on the aetiology of the condition. It is hypothesized that the onset of coprolalia in patients with persistent childhood tics indicates a disturbances of the normal balance between a need for tension relief by swearing and a capacity to control such vocal activity. Some conclusions are drawn on the management of the syndrome by the use of butyrophenones, massed practice of tics, and the promotion of personality development. A flexible approach geared to the individual patient's particular needs is recommended.


Atypical measles infections in leukaemic children on immunosuppressive treatment. One case of giant-cell pneumonia and two of encephalopathy, all due to measles infection in children in leukaemic remission on immunosuppressive treatment, were seen recently. The clinical syndromes were variable and atypical and the antibody responses unpredictable. Conventional doses of pooled immunoglobulin failed to protect the two children to whom it was given. Degeneration rather than inflammation seems to characterise the encephalopathy in immunosuppressed children infected with measles virus.


Antitumor activity of N-(phosphonacetyl)-L-aspartic acid, a transition-state inhibitor of aspartate transcarbamylase. N-(Phosphonacetyl)-L-aspartate (PALA) is an analog of the transition state for the aspartate transcarbamylase reaction and has been reported previously to be a potent and specific inhibitor of de novo pyrimidine nucleotide biosynthesis. It is now shown that PALA has considerable antitumor activity against certain transplantable tumors in mice. PALA, unlike other antimetabolites, was less effective against ascitic leukemias than against two solid tumors, B16 melanoma and Lewis lung carcinoma. Another solid tumor, Ridgway osteogenic sarcoma, which is sensitivie to many established chemotherapeutic agents, did not respond to PALA. Daily or intermittent treatment with PALA did not significantly increase the life-span of mice bearing i.p. leukemia L1210. The survival time of mice bearing i.p. P388 leukemia was prolonged by PALA treatment by up to 64%. In a number of experiments mice bearing i.p. B16 melanoma survived 77 to 86% longer than did controls when treated with PALA (490 mg/kg) on Days 1, 5, and 9. Lewis lung carcinoma, a tumor refractory to most established antineoplastic agents, was highly sensitive to PALA. Treatment on Days 1, 5, and 9 following s.c. implantation of Lewis lung carcinoma was curative to 50% of the mice. If treatment was delayed until s.c. Lewis lung tumors had reached about 500 mg, PALA neither cured the mice nor produced significant tumor regression. However, extensive delay of tumor growth and prolongation of survival were still observed.


Elaboration of pyrimidine-specific nucleosidases by human lymphoblastoid cells of established cultures. Pyrimidine-specific nucleosidases were released rapidly by human lymphoblastoid cells of established cultures when incubated under certain culture conditions having no adverse affect on their viability or morphology. Nucleosidase production was not restricted to any particular type of lymphoblastoid line; enzymes with a high level of activity were elaborated by cells of cultures initiated from healthy subjects and patients with uncontrolled lymphocytic or myelocytic leukemia, as well as by cells of cultures exhibiting mostly B- or T-cell properties. Tritiated thymine and uracil, which were not incorporated to any appreciable extent by DNA- and RNA-synthesizing cells, were identified by paper chromatography as the primary products arising from nucleosidase degradation of radiolabeled thymidine, uridine, and cytidine. Neither adenosine nor guanosine was catabolized. These heat-labile and ultraviolet-sensitive enzymes with a molecular weight of  5 to 10 X 10(4) did not affect the viability, morphology, or proliferation of lymphocytes in mitogenactivated cultures, lymphoblastoid cells in long-term cultures, or fibroblasts in monolayer cultures.


Biologic activity of two derivatives and six possible metabolites of cyclophosphamide (NSC-26271). The biologic activity in terms of survival of normal hematopoietic stem, osteosarcoma, and L1210 leukemia cells was determined for the following compounds:cyclophosphamide, its derivatives isophosphamide and trophosphamide, its possible metabolites nor-nitrogen mustard, hydroxylamine mustard, 4-ketocyclophosphamide, and and acrolein, and two substitutes for its primary active metabolite 4-hydroxycyclosphamide anhydro-dimer (4-hydroxy-CP-anhydro-dimer) and 4-hydroperoxycyclophosphamide (4-hydroperoxy-CP). On a molar basis none of the compounds shows a better therapeutic ratio between osteosarcoma and bone marrow stem cells than the parent compound. The therapeutic ratio between L1210 leukemia and normal cells is slightly better for 4-hydroperoxy-CP only. It may be concluded that the conversion of 4-hydroxy-CP-anhydro-dimer and 4-hydroperoxy-CP to the primary active metabolite 4-hydroxycyclophosphamide differs quantitatively. Moreover, it appears that by the use of these precursors a better therapeutic ratio might be obtained for some malignancies but not for others.


Studies on the enhancement by cyclophosphamide (NSC-26271) of artificial lung metastasis after labeled cell inoculation. In a mouse model the retention of125I-5-iodo-2' -deoxyuridine-labeled tumor cells in the lung after iv injection was compared with the formation of tumor colonies in the lung 15 days after injection. The modification in lung retention after treatment with cyclophosphamide (CP), isophosphamide, Corynebacterium parvum, and heparin paralleled the changes in lung-colony numbers by these treatments. Since the modifications could be identified as early as 1 hour after iv administration of tumor cells, further evidence was obtained for the conclusion reached earlier that the modification of lung metastases by CP and Corynebacterium parvum is not due to immunologic mechanisms. Comparison with the lung retention of heat-killed tumor cells and living embryonic cells showed that CP induced an increased retention of all three cell types. In contrast, Corynebacterium parvum decreased the retention of living tumor cells, but failed to modify the retention of dead tumor cells, but did not affect the retention of living embryonic cells. Since no similar cell types were affected by the various treatments it seems likely that different mechanisms are involved. Apparently CP decreases the nonspecific resistance against the lodging and growth of any type of cell in the lung.


The physiological responses to walking uphill under hot environment. A series of human experiments on walking uphill under radiant heat in addition to hot environment were carried out and the safety conditions for walking uphill from the standpoint of physiological response were determined. Experiments were carried out on three healthy adult males aged 21 years, walking uphill on a motor-driven treadmill with the aim of walking at a speed of 45 m/min, 55 m/min and 65 m/min and with a slope gradient of 0 degrees, 5 degrees and 10 degrees. The load weight used was 30, 40 and 50 percent of the body weight for each combination of speed, gradient and load weight. The subjects were exposed to a radiant heat of 1.3 cal/cm2.min, using 12 exsiccating infrared lamps, with a room temperature of 33 degrees C, a relative humidity of 60% and an airflow of 0.7 m/sec. The following results were obtained by estimating the physiological response (heart rate, respiration rate, rectal temperature and RMR (relative metabolic rate)) to different degrees of walking conditions during the 10-minute exercise: 1) The work intensity (RMR) of uphill walking with a certain load weight under hot environment can be changed by varying the walking speed and the load weight according to the slope gradient. 2) As there exists a gap between RMR 5 and 6 in parallel with the other physiological responses, it is preferable to keep the walking condition under RMR 6, as viewed from the change of the other walking conditions. 3) The heart rate as an indicator of the work load must be kept below 130 beats/min for a safe uphill walking of under RMR 6.


Radioisotope scanning for the spinal cord tumor. Radioisotope scanning with 99mTc-pertechnetate or 67Ga-citrate for the spinal cord tumors was reported. Six patients with spinal cord tumors including 2 ependymomas, 1 neurinoma, 1 metastatic medulloblastoma, 1 metastatic astrocytoma, and 1 metastatic pinealoma as well as 6 patients with non-neoplastic lesions were examined with this method. Two out of 6 cases with tumors showed positive scans and two equivocal scans. This new method is different from myeloscintigraphy and radioisotope angiography as already reported. It directly demonstrates tumor itself like brain scanning and is very useful as nontraumatic method for screening spinal cord lesions, especially in poor risk patient. The usefulness and limitation of this method are discussed.


The Paneth cell in the adenoma of familial polyposis coli. It is said that the Paneth cells are found in the large intestine in a pathological state such as ulcerative colitis or adenoma. We examined the Paneth cells in the adenomas of familial polyposis coli. Nine cases including one case of Gardner's syndrome comprised the material for the examination of the Paneth cells because the caecum was available for the examination. The remaining one case had no Paneth cells. In two cases, the Paneth cells were found among the adenomas in the areas beyond the caecum and the proximal part of the colon ascendens. In one remarkable case, the Paneth cells were found in 43% of the adenomas in the caecum. Seven cases were carcinomas but no Paneth cells were found in or near the carcinoma. In the control cases, which were taken from the resected colon with a disease other than familial polyposis coli, the Paneth cells were found confined to the caecum. We concluded that the distribution of the Paneth cell-bearing adenomas reflects the distribution of the Paneth cells in the normal mucosa of the large intestine and that the Paneth cells in the adenoma may have differentiated in the adenoma.


Cleavage lines in the oral mucosa and oral scars. Previously published data on the mucosal cleavage lines were compared with data on the formation of scar tissue after palatoplasty and it was found that, in the palate and surrounding tissues, scar formation is light when incisions are parallel to the long axis of the cleavage lines but severe when incisions are made at right angles to the cleavage lines. A few cases were also found where jaw movement was severely restricted because of the formation of hypertrophic scar between the upper and lower alveolar ridges. It is therefore desirable that surgical incisions in thepalate and surrounding tissues be made parallel to the long axis of the mucosal cleavage lines.


Treatment of restricted jaw movement due to scars after palatoplasty. In order to correct the condition or restricted jaw movement due to hypertrophic scar tissue after palatoplasty, the scar is first cut laterally. After cutting away the scar tissue from under the mucosa and suturing the incision longitudinally, a drastic improvement in free faw movement is obtained.


In vitro studies of bone resorption by the root-resorbing tissue from the bovine deciduous tooth. Granulation tissue which is responsible for root resorption of deciduous tooth lies between root of the deciduous tooth and its permanent tooth germ. This tissue is called "root-resorbing tissue". Its bone-resorbing activity was investigated in vitro. Bovine root-resorbing tissue was cultured in close contact with 45Ca-labeled dead calvaria of rats. Bone-resorbing activity was determined by measuring 45Ca released from labeled calvaria during culture. It was found that only the root-resorbing tissue which was rich in odontoclasts and had a good blood supply in its surface layer had bone-resorbing ability, and that bone resorption occurred only when it was placed in close contact with calvarium. The root-resorbing tissue which was poor in odontoclasts and blood vessels failed to stimulate by 25-hydroxy-vitaim D3 or heparin, but not by larger amounts of parathyroid hormone, vitamin D3, and dihydrotachysterol when added to the culture.


A clinico-pathological survey of exophytic tumors of the urinary bladder. I. An analysis of the structure of the fibro-vascular cores with special references to the clinical prognosis. In this paper the results of the clinicopathological study on a total of 79 bladder tumor cases are presented. They are principally related to the stromal proliferation or branching of the tumors. The tumor cases consist of those with a good prognosis as well as those with a poor prognosis. In the former category there are 61 cases with a long survival history (with or without recurrence); the remainder (18 cases) had a history of a short survival (dying within 2 years). Histologically there was a marked difference in the regularity of the stromal branching of the tumor between those cases with a long survival history and those cases with a short survival history. In the former group the regular type of stromal branching was predominant; in the latter group the irregular type was predominant.


Renal microvasculature in chronic renal failure. The renal microvasculature was examined stereoscopically after intraarterial injection of silicone rubber. Specimens studied were: 29 cases of normal kidney, 4 cases of sclerotic kidney, 10 cases of acute renal failure, and 10 cases of chronic renal failure from the final stage of chronic glomerulonephritis, malignant nephrosclerosis, diabetic nephropathy, and cortical necrosis. The following were common evidences for chronic renal failure: much reduction and wide deficiencies of filling in the cortex, increased filling of vasa recta, narrowing and spiralling of interlobular arteries and cortical afferent arterioles, appearance of giant glomeruli, rarefaction of the peritubular capillary plexus, and relative preservation of glomeruli in the juxtamedullary zone and vasa recta in the medulla may be the major pathway, after the interlobular arteries and afferent arterioles in the subcapsular cortex are destroyed, and these vascular architectural changes may be intimately related to the pathophysiology of chronic renal failure.


Clinical studies on diabetes mellitus and diseases of the oral region. Of the 25,672 patients who visited this clinic between January 1964 and March 1973, 126 were diabetic. These were examined statistically and the following results were obtained. 1. Together with diabetes the following disorders pertaining to the realm of oral surgery were observed: Alveolar pyorrhea (49 cases), infection of oral tissues other than periodontal tissues (24 cases), simple periodontitis (15 cases), tumors (13 cases), dental caries (9 cases), neuralgia (6 cases) and several disorders. 2. Of these 126 cases, 85 needed tooth extraction, which was actually performed in 67 cases with the following results: (a) Of the 67 cases, 13 developed complications such as dry socket, postoperative infection, sequestrum around the extraction socket, etc. This was a significantly higher incidence than in an equal number of controls. (b) In the cases with complications convalescence was prolonged to an average of 54.2 days. (c) In the cases with complications, the preoperative fasting blood sugar level averaged 194.5 mg/dl, which was much higher than in the cases which did not develop complications (average 142.4 mg/dl).


The color of gingiva studied by visual color matching. Part I. Experimental studies on the discrimination threshold for color difference and effect of training. As a preliminary experiment on the gingival color indicated by Munsell system, the makings or the qualities for color sensation of the individual were checked with regard to (1) discrimination threshold for color difference with certain color range of gingiva (paired difference test for color comparison) and (2) promotion of memorial power by training (test for memory color). A total of 20 males and females (20-30 years old) participated in this preliminary study as experimental subjects and the following results were obtained: (1) the average color discrimination threshold for color difference among subject trained for color memory is 0.8 Lab. (Hunter), and is assumed to be greater in the actual colorimetry of gingiva, (2) the similarity of discrimination is more frequent among the subjects trained for color memory than among those who were not trained, and (3) training for color memory is found to be effective in promoting the ability for color discrimination.


Interaction between polymeric materials and tissue -- biodeterioration of polymeric materials. Styrene-isoprene block copolymer/methyl methacrylate graft copolymer (SIS-MMA), styrene-butadiene block copolymers (SBS), polyethylene, 1,2-polybutadiene, polysulfone, polycaprolactone polyurethane (PU) and ethylene-vinyl acetate copolymer (EVA) were implanted subcutaneously in dogs for 1 year. The same materials were stored in physiological saline solution at 37 degrees C (in vitro) and in air at room temperature (in air) for 1 year for comparative purpose. Biodeterioration or biodegradation of these materials was studied by mechanical property testing, viscometry, x-ray diffractometry, infrared spectroscopy and microscopy. A little deterioration of the mechanical properties of all the implanted samples was noticed as compared with the samples stored in vitro and in air. The infrared spectrum and x-ray diffraction pattern of the implanted sample except SIS-MMA were practically identical with the control. The implanted samples of SIS-MMA and SBS showed a cracked surface under a differential interference microscope. Viscosity measurements suggested a possible main chain scission for SIS-MMA and cross-linking for SBS and showed that the molecular weight of the other materials was almost unchanged. The intactness was rather surprising in regard to the infrared spectrum and viscosity of PU and EVA, because they were supposed to be more biodegradable. Deterioration of the mechanical properties was not always due to the results of biodegradation, as is often believed, but it must be considered that it might also be due to the absorption of some constituents such as lipids, steroids and amino acid from the body fluids and/or leaching of low molecular weight substances from the implanted materials.


Osteosarcoma associated with metallic implants. Report of two cases in dogs. This is a report of two dogs in which osteosarcomas arose in association with metallic orthopedic implants. One neoplasm occurred in the distal humerus of a 12-year-old Doberman Pinscher. A stainless steel intramedullary pin had been implanted in the bone 11 years previously. Upon removal, corrosion of the pin was noted. The second neoplasm arose in the proximal tibia of a 12-year-old Irish Wolfhound. Six years previously, a fracture of the tibia had been repaired with a plate and screws made of the same type stainless steel, type 316L, by the same manufacturer. No corrosion appeared to have occured. Infection had not occured in either animal.


Growth characteristics of pulmonary metastases from osteosarcoma. Pulmonary metastases were measured in 7 patients with osteosarcoma. The growth curve of these metastases appears to conform closely to a Gompertzian function, a mathematical description widely accepted as a model for tumor growth in animal systems. Growth curves for pulmonary metastases were projected backwards assuming exponential growth for that period between amputation and initial roentgenologic detection. Lesion size at the time of amputation is estimated and found to vary widely from miniscule lesions of a few cells to large foci destined to become roentgenographically detectable within a few weeks of amputation.


Transforming factors in human sarcoma cells in tissue culture. Experimental data are presented which demomstrate the existence of a transmissible factor(s) in the majority of samples of leukemic bone marrow. This factor(s) is associated with the presence of a cytoplasmic antigen which can be detected by fixed immunofluorescence test with sera of patients with osteosarcoma, leukemia and some apparently normal individuals. Cultures of leukemic bone marrow carrying this factor(s) also form multinucleated cells when exposed to RD114 virus or cels. This factor(s) is transmitted into susceptible whole human embryo cells by cell-free culture fluid. Appearance of the new antigen can be detected by fixed immunofluorescence test about 6 weeks after transmission. Cultures showing the new antigen also form multinucleated cells following co-cultivation with RD114 virus or cells. Co-cultures of human osteosarcoma cells and leukemic bone marrow cells undergo morphologic as well as antigen changes after a long period of time (at least 3 months). Cell line fluids from these cultures contain a factor which induces in recipient whole human embryo cultures both the new antigen and morphological alterations resembling those observed in the co-cultures. Cell-free fluids from leukemic bone marrow and sarcoma cultures as well as from short-term co-cultures have failed to produce morphological alterations in whole human embryo cells. Extensive electron microscope studies carried out at different stages of the experiments have failed to reveal the presence of viral particles. The morphological changes resemble those induced in susceptible cells by sarcoma viruses. The described factor(s) may conceivably represent subviral components capable of biological activity. While suggestive of viral involvement in human sarcoma of bone and soft tissues, there is no definite proof of viruses being the causative agent(s) of human sarcoma. Present evidence provides only a basis for search of additional ways of treatment of human sarcoma to those of surgery and radiotherapy. Present treatment consists of chemotherapy as adjuvant treatment directed against viral markers represented by enzymes, nucleic acids and proteins of possible viral origin, resembling those already known to be present in animal bone and soft tissue sarcomas. However tenuous the contention of the possiblity of viral involvement in human osteosarcoma may appear, adjuvant therapy directed against viral markers warrants the attention of orthopedic surgeons and other clinicians.


Spontaneous pneumothorax and pulmonary malignant disease--a syndrome sometimes associated with cavitating tumours. Report of nine new cases, four with metastases and five with primary bronchial tumours. Tumours of the lung, primary or secondary, may occasionally be complicated by a pneumothorax, and on rare occasions this may be the presenting feature. Metastatic tumours associated with pneumothorax arise usually from bone or soft tissue sarcomas and hence are more common in the young.


[Differential diagnosis of atypical chronic myeloid leukaemia]. Observations in six adult patients with leukaemic differential white counts, predominantly mature-celled, and with hepatosplenomegaly show that the mature-celled but fulminant (para-)neutrophil leukaemia must be differentiated from Ph1-positive chronic myeloid leukaemia. This (para-)neutrophil leukaemia is probably identical with the previously described atypical chronic myelosis of the adult, chronic myeloid leukaemia of childhood and the Pelger-like chronic myeloid leukaemia. Cardinal signs are a mature-celled differential count, short life expectancy (1 year), initial platelet deficiency, increased activity of granulocyte alkaline phosphatase, absence of Ph1-chromosome, and poor therapeutic response to busulfan. This curious and yet apparently not uncommon disease has been observed in the adult age group predominantly in men. The frequently high HbF level observed in juvenile chronic myeloid leukaemia could not be demonstrated in adults. Some of these neutrophil leukaemias are characterized by medullary fibrosis and terminal increase of immature blast cells (blast crises?) of which the diagnostic reliability is still disputed.


Psychological aspects of white.

Psychological aspects of white. An attempt is made to answer the questions: Is white a color? How do we see fluorescent and non-fluorescent whites? What is the psychological and symbolic significance of white? A qualitative study was based on a sample of 1818 people from 24 differentiated groups from the age of 6 upwards. Two techniques were used in the enquiry: the well-known word association test, and a non-verbal method, new to psychology, which was devised specifically for the purpose of defining the psychological significance of white by emotional reference to a set of grey shades, a set of chromatic colors and a set of simple shapes. In a quantitative study, a sample of 1994 people were asked their reactions to fluorescent and non-fluorescent whites. This work was supplemented by linguistic investigations of the anthropological and physiological significance of white. The conclusion reached is that white meets a psychic need in man. Almost all the respondents attributed the characteristic of "whiteness" only to fluorescent whites.


Limits of accuracy obtainable in the direct determination by fluorimetry of fluorescent whitening agents on thin layer chromatograms. The quantitative direct determination of fluorescent whitening agents (FWAs) by thin layer chromatography involves limits of detection of 0.001 to 0.0005 mug. Visual assessment is about ten to a hundred times less sensitive than photometric measurement on thin layer chromatograms. The standard deviations in 10 measurements of two substances with different degrees of light sensitivity for a single measurement with a limit of detection of the order of 0.005 mug were about +/-13% to 44%. In the higher concentrations normally used (0.5 mug), the standard deviations were only +/-5% for both substances.


Direct determination of fluorescent whitening agents by absorption measurement in situ on thin layer chromatograms. The measuring technique for the chromatogram spectrophotometer (Zeiss) to determine the reflectance curves, the analysis according to the Kubelka-Munck function, and the basic outlines of the quantitative determination of stilbene fluorescent whitening agents (FWAs) are explained.


Comments on the isotope technique of determining fluorescent whitening agents. The notes on the specific marking of fluorescent whitening agents (FWAs) refer to publications in the literature and the example of an autoradiographic measurement of an 35S-labelled FWA of the 1,3-diphenyl-2-pyrazoline type.


Limits of accuracy obtainable in the direct determination by fluorimetry of fluorescent whitening agents in solution. In direct determination by fluorimetry the limits of detection are governed by the restricted light stability of fluorescent whitening agents (FWAs) in solution. The initial value of a fluorimetric reading can be registered by a rapid recorder, and in this way very light sensitive traces of FWAs as low as 10 parts per thousand million can be measured be measured with a statistical standard deviation of +/-15% for a single measurement and a reproducibility of +/-50% with a statistical certainty of 99%.


Bleed fastness of fluorescent whitening agents in mass whitened paper. Paper samples mass whitened with fluorescent whiteing agents (FWAs) of three different types (di-, tetra-, and hexasulfonated derivatives of 4,4'-diaminostilbene-2,2'-disulfonic acid) were examined for bleed fastness in five different eluents. Fluorescece intensity was measured by a sensitive spectrofluorimetric technique instead of the usual visual assessment. The degree of bleed obtained from each of the FWAs tested was less than 0.4mg/600 cm2 of paper surface area. The FWAs were applied at a normal concentration of use i.e. 0.05% active substance. FWAs with a high degree of sulfonation tend to bleed in aqueous solvents, and those with a lower degree of sulfonation in alcohol solutions. In aqueous acid solutions the degree of bleed was very low in all cases (0.04 mg/600 cm2 of paper surface area). In fatty solutions there was no bleed at all. The limit of detection was 3mug/600 cm2 of paper surface area, with an accuracy of +/-15%.


Analysis of river water and drinking water from seven European countries. During the months of June to August and September to December 1972 and again from January to April 1973, the river and drinking water at a number of points in seven European countries was examined for fluorescent content. The purpose of the river water studies was to identify any traces of fluorescent whitening agents (FWAs) and relate them as far as possible to knolementary role and also helped to interpret the scatter of the control level of the river water studies. Identification and separation were carried out by means of a combination of spectrofluorimetry and thin layer chromatography. Detection limits and reproducibility of the methods of determination are explained in the chapters V/3-7 (methods of analysis for FWAs. The second river water survey showed that at only one sampling point (Borås in Sweden) there was detectable concentrations (up to 8 ppb) of a lipophilic unsulfonated FWA [2, 5-BIS (BENZOXAZOL-2-YL)THIOPHENE], And these were still about 1 ppb in the third survey. JENSEN and co-worker had previously detected this substance at the same location. No traces of FWAs were detected in any of the other tests. The detection limit in river water was 0.01 ppb (1 part per American billion = 10(-3) gram per metric ton). For identification purposes, a test mixture of six FWAs each with a different chemical constitution and different fields of application was used, and this was first exposed to light in an aqueous solution for some minutes.


Measurement of the uptake of a 14C-labelled fluorescent whitening agent by fish from water and through a model food chain. A laboratory technique is described which simulates the uptake of a fluorescent whitening agent by fish directly from the water and indirectly through a model food chain. The use of radioactive labelled material enables the direct and indirect uptake and possible accumulation of the compounds to be measured quantitatively. The results are expressed as concentration factors. Between ecological and toxicological data a safety relationship is established.


Pilot trials with a fluorescent whitening agent of the bis(triazoly) stilbene-disulfonic acid type in golden orfes. Golden orfes were examined for uptake, distribution, and elimination of radioactivity administered in the form of a 14C-labelled fluorescent whitening agent (FWA) of the bis(triazolyl)stilbenedisulfonic acid type. Results of these studies are given below. Pilot trials using FWA concentrations of 10 and 100 ppb and a population density of 1 fish per liter show that an equilibrium between uptake and elimination of the FWA develops in the animals within a period of one week; i.e., the incorporated traces of the FWA are not irreversibly bound. The radioactivity is mainly located in the gall bladder and in the intestinal contents, as well as in the liver, throat, and gills. The muscular system (filet) is virtually free from activity. Approximately 1-2% of the FWA amount administered per animal (corresponding to the concentration factors of 7-14) can be temporarily detected in the fish. Radioactivity is eliminated comparatively quickly. Two days following the transfer of the fish into water free from FWA a concentration factor as low as 1 is reached, i.e. from this time the FWA concentration in the animals decreases to less than 10 resp. 100 ppb.


Metabolic behaviour of water-soluble fluorescent whitening agents in the rat and bean plant. The behaviour of three representative water-soluble fluorescent whitening agents (FWAs) was studied in rats and bean plants using 14C-labelled compounds. Following oral doses of 5 mg/kg of each of the FWAs to rats, rapid and complete excretion of radioactive material was observed, with an excretion half life ranging from 7-13 hours. Faeces were practically the only route of excretion, indicating, in combination with the short half life times, that no significant amounts of whitener were absorbed from the digestive tract. No radioactive residues were found in blood, liver, kidney, brain, muscle, or fat 96 hours after dosing (limit of quantitative determination 0.005-0.01 ppm Fwa equivalents). Whereas, after application of compound (1) and compound (3), radioactive material was completely extractable from faeces in the form of unchanged parent compounds, that in the compound (2) experiments was not extractable. When bean plants (Phaseolus vulgaris) were grown in the presence of 14C-labelled compound (3) in nutrient solution (11.5 ppm) and in soil (,7.5 ppm), approximately 55% and 2%  of the applied radioactive material, respectively, was absorbed by the plants. More than 90% of thie material was bound to the roots in both experiments 40 days after the application. Eight percent of the radioactive material absorbed in the soil experiment was translocated mainly into the stems whereas only trace amounts of the order of less than 0.1 ppm reached the leaves and bean pods. It is concluded from these experiments with extremely high concentrations of compound (3) that under the conditions which may occur in practice residues of water-soluble FWAs do not appear in substantial amounts in edible parts of crops.


Mechanism of whitening and quenching.

Mechanism of whitening and quenching. The processes of radiation absorption in a molecule and the energy release by thermal or chemical deactivation, phosphorescence, and fluorescence are outlined briefly, and the difference between fluorescent and non-fluorescent dyestuffs is discussed under physical aspects. After a description of the optical mode of action of fluorescent whitening agents (FWAs), the colorimetrical methods of characterizing FWAs and evaluating the whiteness are investigated.


Toxicological investigations with fluorescent whitening agents. The reasons for which toxicological investigations are carried out are: -handling and consumer safety, -the critical attitude of the public towards the use of chemicals in general, -the need to weigh benefit against risk when using chemicals, and -the safety requirements introduced by authorities. The guidelines for toxicological evaluation of chemicals and particularly fluorescent whitening agents (FWAs), as well as the extent of which man is possibly exposed to these substances through alimentary intake or through contact with the skin are discussed. It is concluded that there is a very wide safety margin for every conceivable use of FWAs.


Acute oral, dermal, and inhalation studies. By appropriate testing procedures, it has been demonstrated that the compounds used as fluorescent whitening agents (FWAs) have a very low order of systemic toxicity in acute experiments. No evidence of dermal toxicity has been found. The full chemical names of the fluorescent whitening agents (FWAs) investigated in this study are listed below. They have been numbered for easy identification and classified by chemical groups.


Study by fluorescence microscopy of the effect of fluorescent whitening agents on the skin of mice. Fluorescence microscopic studies of the skin of hairless mice showed that a fluorescent whitening agent (FWA) of the bis(phenyltriazolyl)stilbenedisulfonate type did not penetrate into the subepithelial layers (dermis and subcutaneous tissue) of the skin after cutaneous application.


Studies on the reaction of skin when exposed to fluorescent whitening agents. In hand washing tests with detergents containing fluorescent whitening agents (FWAs), the amounts of whitener left on both hands were determined by TLC spectrophotometry: they varied from 0.06 mg to 0.17 mg. Whiteners of different chemical constitutions behaved in a very similar manner. After 24 hours the skin of the treated hands was virtually free of whitener.


Chronic toxicity and carcinogenicity studies with FWAs. Compounds (1), (2), (3), and (4) caused no adverse toxic effects and yielded no evidence of carcinogenic activity in a 2-year feeding study in albino rats at dietary levels up to 1000 ppm. Compounds (2), (3) and (4) were without effect in a 2-year study in beagle dogs at levels up to 2000 ppm. Compound (1) at levels of 400 and 1000 ppm led to decreased weight gains in some dogs and caused doserelated pathology consisting of inflammatory changes on the serosal surfaces of abdominal viscera and increased hematopoietic acitivty of the spleen and liver cords. These effect could have been due to the feeding of material, without adjustment of pH, for the first 30 weeks of the study.


Photocarcinogenesis: lack of enhancement by fluorescent white agents. These studies were designed to determine whether fluorescent whitening agents (FWAs) could: (I) produce an augmented acute response of skin to a single ultraviolet light exposure (i.e., phototoxicity), or (II) increase the number or hasten the appearance of skin tumors after several ultraviolet light exposures (i.e., chemically enhanced photocarcinogenesis). Five substituted stilbene FWAs were screened for phototoxicity. The results of pretreatment with these agents were compared with pretreatment by a known photoxic agent, 8-methoxypsoralen (8-MOP) or the vehicle (methanol) using the skin of hairless mice, miniature pigs, and man. None of the FWAs was phototoxic. Photocarcinogenesis testing involved pretreating hairless mouse skin with FWAs, 8-MOP, or methanol only before each daily exposure to simulated solar ultraviolet light. In terms of tumor yield and tumor development time, photocarcinogenesis was enhanced by 8-MOP, but not by FWAs.


Studies of embryo toxicity in rats and rabbits. Embryo toxicity studies were carried out to investigate the effects of different doses of fluorescent whitening agents (FWAs) after oral administration to pregnant rats from the 6th to the 15th day of pregnancy and to rabbits from the 6th to the 18the day of pregnancy. In own studies two FWAs of the bis(triazinylamino or triazoly)stilbenedisulfonic acid type showed no embryo-toxic or teratogenic effect on wither species at daily doses up to 1000 mg/kg. Also the toxic dose to the mothers, 3000 mg/kg, given to rabbits in case of one FWA was without these effects. In the studies of KEPLINGER, et al. (Toxicol. Appl. Parmacol. 27: 494-506, 1974) a triazolylstilbenemonosulfonic acid derivative, two bis(triazinylamino)stilbenedisulfonic acid derivatives and a bis(sulfostyryl)diphenyl derivative had no terato-enic effect on rabbits when administered orally in doses of up to 30 mg/kg/day.


Three-generation Reproduction studies with FWAs. Four fluorescent whitening agents (FWAs), compounds (1), (2), (3) and (4) (see table 1) were investigated for their effects on the reproductive performance of albino rats through 3 successive 2-litter generations at dietary levels of 40, 200, and 1000 ppm. Except for slight and random effects of compound (4) on pup survival, no adverse effects were observed. The random effects with compound (4) were not consistently related to either dose level or cumulative duration of exposure through the 3 generations.


Testing mutagenic properties with the dominant lethal test on the male mouse. Mytagecity studies were carried out with fluorescent whitening agents (FWAs) using the dominant lethal test on male mice. Own tests with five FWAs, and those of KEPLINGER, et al. (Toxicol. Appl. Pharmacol.27: 494-506, 1974), with four FWAs, are described. In our tests, acute oral administration of five FWAs at a dose of 5000 mg/kg body weight gave no evidence of a mutagenic effect during 8 weeks' mating. The FWAs used were three bis(triazinylamino)stilbenedisulfonic acid derivatives and a 1,3-diphenyl-2-pyrazoline derivative. The results of the tests carried out by KEPLINGER, et al. showed that intraperitoneal injection of the four FWAs produced no mutagenic effect during six weeks' mating; the whiteners used were a triazolylstilbenemonosulfonic acid derivative (50 mg/kg), two bis(triazinylamino)stilbenedisulfonic acid derivatives (50 mg/kg) and a bis(sulfostyryl)biphenyl derivative (10 mg/kg).


Nucleus anomaly test and chromosomal analysis of bone marrow cells of the Chinese hamster and dominant lethal test in male mice after treatment with fluorescent whitening agents. Four fluorescent whitening agents (FWAs) were tested for mutagenic activity after oral administration in the following three different mammalian test systems: (1) Dominant lethal test in the male mouse; (2) Cytogenetic studies on metaphase chromosomes from the bone marrow of the Chinese hamster; (3) Nucleus anomaly test in somatic interphase cells (bone marrow) of the Chinese hamster. These investigations yielded no evidence of dominant lethal effects of any of the four compounds on the progeny of male mice. Furthermore, the data obtained from chromosome analyses and the nucleus anomaly test revealed no effects at all. Thus, the results obtained in all these tests gave no indication of mutagenic activity after the administration of these compounds in dosages up to approximately 1/3 or the LD50.


Legal aspects.

Legal aspects. The manufacture, application, use and disposal of fluorescent whitening agents (FWAs) may give rise to legal questions relating mainly to environmental protection and the effects on man and animals. In addition to legal aspects, certain commercial aspects such as the law of competition and the obligations of industry, including compensation for damage caused by FWAs, are discussed.


Technical aspects of whitening.

Technical aspects of whitening. The applicational and ecological advantages of whitening over conventional bleaching processes in the textile and paper industries are outlined.


Whitening of textiles.

Whitening of textiles. In the textile field, fluorescent whitening agents (FWAs) can be used on practically all types of goods at any stage in the finishing process. As examples, three important types of methods for applying FWAs to textiles have been outlined.


Fluorescent whitening agents in detergents. Washing is a form of textile care which is characterized by its repetitive nature. Washing methods vary enormously in different parts of the world. The main types of detergents and fluorescent whitening agents (FWAs) are described. Washing slows down the deterioration in use of white goods, and yellowing is counteracted by FWAs. FWAs also enhance the freshness and brightness of most pale shades. Cost calculations show clearly the economic advantages of using FWAs in washing: the useful life of textiles can be prolonged considerably for a very small additional cost.


Mass whitening of synthetic fibers and plastics. The evaluation of new and improved techniques has led to the development of mass whitening methods for use with synthetic fibers and plastics. The processes are complex but well defined, and call for the use of sophisticated fluorescent whitening agents (FWAs) to meet the requirements of the fiber or plastics manufacturer, the textile finisher, and the end user. The performances of some leading commercial whiteners are compared and their interactions with dyes, fillers and stabilizers are discussed.


Measurement of fluorescent white effects and whiteness. This report surveys the literature and describes various techniques of whiteness measurement and evaluation in current use. Measuring techniques are described for dealing separately with the effects obtained by bleaching, blueing and fluorescent whitening, and an example is given of the direct quantitative estimation of a fluorescent whitening agents (FWAs) on a substrate by measuring reflectance in the ultraviolet region. Another chapter deals with the colorimetric estimation of the whiteness and the shade of a fluorescent white using modern apparatus in conjunction with a programmable minicomputer. A new simple and universally applicab,e formula was worked out: W=D-Y+P-x+Q-y+C which has been successfully used in routine tests and which for the first time gives different weight to whiteness values corresponding to all shade preferences existing in theory. Each user can match the formula to his own preference by appropriate adjustment of the D, P, Q andC values. Y,x and y are the customary colorimetric values as standardized by the CIE (Commission Internationale de l'Eclairage). It was also found that with another formula the shades of fluorescent whitening effects (green to red tints) may be defined in a simple way.


Qualitative thin layer chromatography of fluorescent whitening agents. Experimental details and examples of a "chromatographic program" for testing the major fluorescent whitening agent (FWA) types and material samples containing FWAs are described.


"Chronic myelogenous" leukemia of juvenile type. Report of two cases and review of therapy. The juvenile type of "chronic myelogenous" leukemia (CMLJT) is a rare disease with only 40 cases reported to date. Clearly distinguishable from adult CML on both clinical and laboratory grounds, is is often confused with "congenital" leukemia, pseudoleukemia, leukemoid reactions or chronic granulomatous disease. According to studies of muramidasuria and colony-forming cells it is neither a chronic nor a granulocytic leukemia. It is a panmyelopathy with monocyte predominance and should thus be classified as a variant of myelo-monocytic leukemia. We review reported responses to chemotherapy and splenectomy and report our results with cytosine arabinoside in the treatment of 2 cases with this disease. Chemotherapy may prolong life and splenectomy may be useful in some cases; but the survival rate is 0%, justifying new approaches.


Nutrition in growth and development of oral tissues. The development of teeth, salivary glands, and other oral tissues can be seriously compromised by a deficiency of a number of essential nutrients. Because nutritional stress during critical development periods may decrease the ultimate resistance of the oral tissues to challenge, the prevention of disease and maintenance of oral health are intimately dependent on the nutrient supply during development. Appropriate dietary counseling, particularly with reference to critical developmental times and intake of essential nutrients, can insure optimal oral tissue development.


Nutritional determinants of the ecology of the oral flora. Consideration of nutritional factors as determinants of oral microbial ecology leads to the conclusion that endogenous factors play a dominant role. It is the interactions between specific microorganisms and nutritional and other factors provided by the host that selectively determine the kinds of microorganisms which willinitially reside in the oral cavity and the sites which they will colonize. The persistence of these original "colonists" in their respective ecologic niches will depend in part on the accessibility of endogenous nutrients variously provided by saliva, tissue exudates, crevicular fluids, or degenerating host cells. It will also depend on their response to and interaction with microorganisms which immigrate to that site subsequently. The microbial ecology of a given site is therefore rarely uncomplicated, the notable exception occurring at the most microscopic level where one may encounter microcolonies of individual species within more heterogenous populations of microorganisms. The extent of this heterogeneity quantitatively and qualitatively is a reflection of the degree to which the interactions between the resident flora and the new arrivals, plus the local environmental changes which they both generate, serve to promote or to discourage the survival and growth of the individual species. This element of heterogeneity in a dynamic system with its inherent potential for variation makes it possible for relatively minor changes in local environmental conditions to result in significant differences in the microflora between one site and another even though they may be in close proximity to each other. Once this concept is appreciated it becomes easy to understand how disease processes such as dental caries may affect specific areas of a tooth while nearby areas are unaffected. The effects of exogenous nutrients on the ecology of the oral microbiota, nevertheless cannot be ignored. The diet may modulate such endogenous factors as the salivary secretions and the local resistance of the gingival tissues to infections. Although at our present state of knowledge the direct influence of dietary proteins and fats on the oral microbiota is thought to be of relatively minor consequence, dietary carbohydrates are of major ecological significance. Dietary sugars provide readily available substrates for the oral microorganisms, most of which depend on carbohydrates for energy sources. The metabolism of dietary sucrose by S. sanguis and S. mutans with the productions of acids and intracellular and extracellular polysaccharides has specific influence on the microbial composition, metabolic activities, and mass of coronal plaque. The ready availability of dietary carbohydrates undoubtedly influences the microflora of other parts of the oral cavity as well, eic species or indirectly through the interactions of other organisms with them...


Nutritional implications in wound healing. Healing of wounds is one of the life functions which is intended as a defense mechanism to maintain the integrity of the body. Understanding basic factors that guide the healing process will help the clinician to propitiate those nutritional measures known to enhance the repair function. Nutrients are normally required for growth, development, and maintenance of the integrity of the tissue. The sum total of the nutritional requirements of all tissues and organs constitutes the requirements of the individual. Recommended dietary allowances have been defined for population groups in the United States for different ages and sex. These allowances involve some 17 different nutrients, but many others (up to 50) are now considered essential, although their exact requirement may not be known. When trauma of any sort is inflicted on an individual, both local and general metabolic changes take place which may lead to nutritional inadequacy. These reactions are normally intended to set into motion the mechanisms designed to repair injured tissues. Nutritional management of the individual requires that the clinican determines what, how, when, and how much nutritional supplementation should be given to the patient. Guidelines for the amounts of proteins, vitamins, and certain minerals to be administered have been discussed. Where there are impediments that make it impossible to feed the patient orally, the clinician should resort to parenteral feeding to insure that nutrients are provided for the convalescing patient. Because the trophic environment will determine to a large extent the speed with which tissues will recover, nutritional care of the patient is important and should be interrelated to the total care of the patient.


Role of nutrition in the oral health of the aging patient. The food, diet and nutrition needs of the elderly patient should be considered a part of his total supportive management. It is incumbent upon the dentist to provide the patient with this nutritional information for optimal oral health, because what is good for preventing oral disease will be equally good for preventing general illness. Essentially, if the clinician keeps in mind that the calorie needs for an older patient are less but all other nutrient requirements are as high in old age as they were in youth, the geriatric patient will be well treated. Certainly there are distinctive environmental, physiological and psychological problems that must be considered, but these should not be imponderable. The best possible general advice is that daily diets should include meat, milk, vegetables and fruit, and bread. We suggest an emphasis on good quality protein foods and a generous selection of vegetables and fruits and somewhat less stress on fats, starches, and sugars to avoid an excess of calories. For the individual geriatric new denture wearer we might add that each diet prescription should be based on an analysis and evaluation of his individual food habits (the "why" of the diet) and actual food intake (the "what" of the diet). Furthermore, the physical nature of the diet should be consistent with the patient's experience and ability to swallow, chew, and bite with his dental prosthesis.


Clinical and laboratory diagnosis of nutritional problems. The objective of this article is to familiarize the dentist with clinical signs and laboratory methods used in diagnosing nutritional deficiencies, and to indicate which laboratory methods may be useful to the clinician in cases of suspected nutritional deficiency. It should be noted that the suggested laboratory methods were selected on the basis of their applicability for the clinical situation as well as their reliability as indicators of nutritional status. Therefore these suggested methods of choice may not in every instance be the most accurate of all indicators of nutritional status for a particular nutrient. The dentist who wishes to utilize one of the laboratory methods has a number of options. He can take the appropriate sample in his office, or refer the patient directly to a clinical laboratory for the simpler analyses, or refer his patient to a physician for appropriate metabolic testing. The first option may be more appropriate for the dentist practicing in areas where a clinical laboratory is not within reasonable distance. In this instance the dentist should contact the laboratory for specific information, such as sample volume and special instructions for taking, handling, and shipping the sample. The second option is available to the dentist practicing in an urban area where clinical laboratory facilities are readily available. Finally, the dentist should work in conjunction with a physician when complex metabolic testing is required.


Why cancer patients have anorexia.

Why cancer patients have anorexia. The theory has been advanced that the anorexia of cancer is the result of anorexigenic peptides and of other intermediary metabolites produced by the cancer and the tumor-bearing host. These metabolites are the signals to peripheral receptors and to the brain centers and are responsible for the state of satiety and aversion to food. Although the only effective way to stimulate the appetite of the cancer patient is to control the cancer, efforts should be made to increase the calorie intake even in the presence of anorexia and to maintain a calorie equilibrium. However, controlled studies have not shown that forced feeding can reverse for long periods the progressive tissue wasting process or prolong the cancer patient's survival.


Enzyme variability in natural populations of Daphnia magna. IV. Ecological differentiation and frequency changes of genotypes at Audley End. Genotypic frequencies were analysed for two years in a permanent population of the cladoceran crustacean, Daphnia magna, which was polymorphic for an esterase and for malate dehydrogenase. Large temporal changes in genotypic frequencies occurred at both loci. There was no evidence of a seasonal pattern in the frequency changes. In most samples, genotypes at the two enzyme loci were non-randomly associated; these associations showed temporal changes. On some occasions marked spatial heterogeneity in genotypic frequencies existed within the population. Genotypic differences in parthenogenetic and sexual egg production were observed. In a primarily parthenogenetically reproducing population, non-random associations between genotypes of structural and regulatory loci will be the rule. The allozyme variants themselves may or may not be under selection. The relevance of these observations to ecological studies on Daphnia is considered.


A demographic analysis of the components of selection in a population of Arctic Skuas. From previously published demographic data of the age distributions and reproductive rates of the pale, intermediate and dark phenotypes of the Arctic Skua, revised estimates are obtained of the intrinsic rates of increase and selective coefficients of the phenotypes in each sex. Two significant components of selection are variation in age of maturity and variation in reproductive success. Sexual selection is a component of the variation in reproductive success. Dark and intermediate birds have a greater reproductive success than pales, partly as a result of their advantage in sexual selection. Pale birds have an overall advantage, however, because they are younger when they first breed. Given the estimated selective coefficients, a computer model predicts that pale birds will gradually replace the others. So far there are not enough data collected over a sufficiently long time to test the model rigorously.


Is sex maintained to facilitate or minimise mutational advance? There are two alternative hypotheses for the selective advantages of sex: (i) The "Fisher-Muller" model:sex facilitates evolutionary adaptation to chaning environments. (ii) The "Rachet" model: sex minimises the mutational load. The relative importance of these hypotheses is discussed with reference to (a) comparative data on sexual and asexual reproduction, (b) the timing of sex in species with asexual/sexual alternation, (c) the advantages of haploid/diploid alternation, (d) the disadvantage associated with the recombinational load. It is concluded that the Ratchet model may well be the major mechanism which maintains sex.


The colour polymorphism in Enoplognatha ovatum (Clerck) (araneae: theridiidae)--temporal stability and spatial variability. Colonies of the visually polymorphic spider Enoplognatha ovatum have been studied in Nidderdale, Yorkshire, for up to six years. Morph frequencies are found to be stable within colonies between years but to vary between colonies only short distances apart. The stability of the polymorphism argues in favour of powerful selection acting on this character. The nature of the selective factors are unknown but they are not those which influence time of maturity of the spiders or the mature female population size, both of which have varied between years. A genetic basis proposed for the polymorphism is considered and rejected as being incompatible with stable morph frequencies.


Annual cycles in the incidence of b chromosomes in the grasshopper Myrmeleotettix maculatus (acrididae: orthoptera). The frequency of B chromosomes has been determined for several stages in the grasshopper life-cycle, over three generations, in three natural populations spanning a steep cline in East Anglia. This has revealed a rise in B frequency in prediapause eggs, a fall during the winter in the embryos and a rise in the early nymphs in certain situations. The causes of these effects are discussed and also their importance, along with meiotic drive, in maintaining an environmentally correlated cline of stable adult B frequencies.


Protein polymorphism in the egg albumen of red grouse (L. Lagopus scoticus). Egg albumen of red grouse was separated by electrophoresis and then stained with naphthalene black. The number of dark-blue bands seen in one zone varied from three to six. The four fastest bands were probably controlled by three codominant alleles at an autosomal locus. The pattern of inheritance of the second fastest band was not clear because the sample was small.


Results of surgical treatment in 65 dogs with osteosarcoma. Clinical and necropsy findings were obtained from case records for 65 dogs treated surgically for osteosarcoma at the University of Pennsylvania Small Animal Hospital between July, 1952, and July, 1973, inclusive.  The median age of the dogs was 6 years. There were 39 males and 26 females. All but 5 of the 65 dogs weighed more than 16 kg. Sixty-two of the osteosarcomas arose from the limbs and 3 from the ribs. The median duration of presurgical clinical signs was 6 weeks, with a range of 1 day to 24 weeks. There were no statistical correlations between the postsurigical survival times and the age, sex, or breed of the dog, the site of the osteosarcoma, or the duration of the presurgical clinical signs. Of the 40 dogs with known lung metastases, 11 also had hypertrophic pulmonary osteoarthropathy. The median survival time was 18 weeks, with a range of 3 to greater than 578 weeks. Twenty-six percent were alive 6 months potoperatively, 13.8% were still alive at 9 months, and 10.7% survived more than 1 year. The total median duration of the disease was 24 weeks (range, 8 greater than 578 weeks).


Pulmonary resection for metastatic osteogenic sarcoma. A retrospective analysis of thirty patients who underwent pulmonary resection for metastatic osteosarcoma over a twenty-eight-year period revealed that most were young males with previous amputations for primary lesions of the lower extremity. In each, one to four thoracotomies had been performed, for a total of fifty-two chest operations with resection of 124 pulmonary metastatic lesions. At last follow-up, eleven of the thirty patients were alive and free of disease. At five years 28 per cent had survived: three of them were alive at more than nine years, and one was alive at nearly twenty years. Adverse survival factors identified were short tumor-free interval and multicentricity of pulmonary metastases. Long-term survival was associated with a tumor-free interval of more than two years and one to four thoracotomies at which few foci were present. As a group, patients selected for lung resection had significantly longer suvival than did patients whose pulmonary metastasis was untreated.


The influence of trauma from occlusion on reduced but healthy periodontal tissues in dogs. The experiments were performed in five dogs fed a soft diet which allowed dental plaque accumulation. Experimental periodontal breakdown was introduced on Day 0. After 180 days trauma from occlusion was produced in 4P and P4 i.e. the mandibular fourth premolars, in the manner described by Svanberg & Lindhe (1973). On day 280 the periodontal pockets around 4P and P4 were eliminated. A notch was prepared in the root at the level of the bottom of the surgically eradicated pocket. In addition, the occlusal trauma in the 4P region was deleted. From Day 280 to Day 370 the teeth of the animals were brushed twice a day. The animals were then sacrificed, radiographs of the premolar regions were taken, and tissue sections comprising 3P4P1M (and P3P4M1) were produced and subjected to microscopic analysis. The results indicate that jiggling type occlusal trauma and tooth hypermobility are not factors which detrimentally affect healing following periodontal surgery.


Minor self-inflicted injuries to the gingivae: gingivitis artefacta minor. Three young patients with gingival injuries that were self-inflicted by a fingernail habit are presented. In each case the habit, which was provoked by a pre-existing locus of irritation, was stoped as soon as the locus (or trigger) was identified and treated. A distinction is drawn between these types of cases, (gingivitis artefacta minor), and those of gingivitis artefacta major where the habit is more deeply entrenched and the implications more serious.


Traumatization of teeth and gingiva related to habitual tooth cleaning procedures. Traumatization of oral hard and soft tissues connected with mechanical oral hygiene procedures has been reported in the dental literature. Definitions, classifications and localization of such lesions are listed, and in vivo and in vitro experiments within the field are reviewed. Existing literature suggests that hard tissue lesions are mainly due to abrasives in dentifrices, whereas gingival lesions may be caused by toothbrushing per se. Factual knowledge about the prevalence, severity and clinical significance, as well as relevant and reliable experiments, is scarce and further research on these topics seems to be indicated.


A laboratory method for assessment of dentrifrice abrasivity. This is the report of the Laboratory Abrasion Committee of the American Dental Association (ADA) Dentifrice Program relative to specific methods to measure the in vitro abrasivity of dentifrices. This method was used in two collaborative studies with six participating laboratories. These studies were designed by the ADA Dentifrice Program Statistical Committee and their interpretations form a basis for recommendations on the use of the method. This laboratory method is recommended for use in dentifrice development and may provide some basis for expectations in normal dentifrice use.


Susceptibility of some plaque microorganisms to chemotherapeutic agents. Investigators have used chemotherapeutic agents topically for plaque control without knowing the drug concentration necessary to inhibit the growth of odontopathic microorganisms. S mutans, S sanguis, A viscosus and A naeslundii are important components of the plaque flora. The minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) of niddamycin, vancomycin, bacitracin, and kanamycin were determined for each organism in liquid culture. These antibiotics were selected because of their low absorption from the gastrointestinal tract. Niddamycin, vancomycin, and bacitracin had the lowest MIC, from 0.2 to 10 units/ml. Kanamycin was inhibitory only at much higher concentrations (130 to 500 units/ml). The corresponding MBC was generally higher than the MIC. A viscosus was the most resistant organism tested. These data are important in designing controlled release devices for delivering a suitable antibiotic on a continuous basis intraorally.


Surface and lamina propria lipids of bovine gingiva. In terms of both quality and quantity, the surface lipids are noticeably different from the lamina propria lipids. The surface lipids are mainly structural in nature (cholesterol, cholesterol esters, and phospholipids), whereas the lamina propria lipids are mostly of storage types (triglycerides). The surface lipids are also more unsaturated, whereas the lamina propria lipids are more saturated. Even though gingiva is histologically similar to skin, bovine gingival surface lipids are different from the bovine skin surface lipids. Further studies are needed to investigate the importance of surface lipids in regulating the various physiologic functions of gingiva.


Effect of premature loss of deciduous canines and molars on malocclusion of the permanent dentition. The effect of the premature loss of deciduous canines and first and second molars on malocclusion of the permanent dentition was studied in 255 schoolchildren 11 years of age or older at the most recent examination of the permanent dentition. Malocclusion was evaluated by scoring malalignment (major and minor) and measurement of crowding in the anterior teeth. Children who had a premature loss of one or more canines or molars had a higher frequency of receiving orthodontic treatment of one type or another for the permanent dentition. The likelihood of need of treatment increased with the number of prematurely lost teeth. Children who had lost one or more deciduous teeth through age 9 had a greater than threefold increase in the frequency of orthodontic treatment relative to the control. Of those who did not receive orthodontic treatment, there was no detectable relationship of the premature loss of canines with the malalignment of permanent teeth. However, there was a significant effect of the premature extraction of molars on malalignment especially major malalignment of permanent teeth. No differences were noted in their effects between the first and second deciduous molars. Crowding of the anterior teeth was directly affected by the premature loss of deciduous canines.


Thermocycling of pit and fissure sealants. Both sealants experience early thermocyclic failure, which is manifested as marginal breakdown or separation. From the 20 to 70% failure range (Fig 5) Nuva Seal was three times as resistant to thermocyclic stressing as was Epoxylite 9075. That is, the Nuva Seal-sealed teeth had to be cycled three times more than the Epoxylite 9075-sealed teeth to effect the same failure rates. Both Epoxylite and Nuva Seal reach the same failure rate at 7,000 cycles (75% failure rate). Extremely careful visual examination is required to detect marginal separation failures of pit and fissure sealants.


Epithelial cells associated with the development of dental plaque. Transmission and scanning electron microscopy were used to study desquamated epithelial cells in the developing and mature dental plaque. Epithelial cells were found attached to enamel as early as one hour after clean enamel cylinders were placed in the mouth, and they were seen in great numbers after two days. These cells generally had bacteria attached to their surfaces. Epithelial cells adsorbed to the surface of the enamel appeared to alter their morphology, and mineralization of these structures was also observed. Desquamated epithelial cells could play a role in the initial bacterial colonization of tooth enamel since it is known that bacteria selectively adsorb onto their surfaces. Hydroxyapatite may affect the morphologic alteration of epithelial cells adsorbed to tooth enamel. From the observation of developing and mature plaque samples, it seems that certain suprasurface pelliclelike structures might be epithelial cells.


Follow-up studies of cortisone teratogenicity in CD1 strain mice. The present study was done to evaluate the incidence of cortisone-induced cleft palate in the offspring of CD1 strain mice whose mothers had been injected with cortisone during their own pregnancy. The incidence of induced cleft palate was as high as the incidence of cortisone-induced cleft palate reported previously for the CD1 strain, indicating that the predisposition of CD1 mice to the teratogenic effects of cortisone is not altered significantly when the F2 generation is treated in utero with the same teratogenic agent.