Experience with 194 posterior chamber lenses in 20 months.

The author describes his experience with 194 posterior chamber lenses, mainly of the Pearce tripod variety. The surgical technique and complications peculiar to this type of prosthesis are considered. It was found that 75 per cent of eyes saw 6/9 or better and that the visual results compared favourably with figures given by other workers using different types of implants. The tripod posterior chamber lens is free of some of the problems associated with other intraocular lenses, especially pupil block glaucoma, hyphaemata, and the contact with plastics of the corneal endothelium. It is felt that the posterior chamber deserves further consideration as the correct place for an intraocular lens, because it provides a more "normal" eye than any other prosthesis.


Effect of intraocular lenses on the corneal endothelium.

Methacrylate surfaces adhere to corneal endothelial cell membranes and appear to tear off the cell membranes as they separate. This adhesion appears to cause much of the massive cell damage seen at the time of intraocular lens insertion even in the hands of several groups of very experienced implant surgeons. The damage appears correlated with the incidence of endothelial touch, and may be avoidable both by avoiding contact, even for a brief period, between the endothelium and the intraocular lens during insertion, and by increasing the safety of such lenses through a hydrophilic protective coating which would give a surface similar to human lens epithelium or soft contact lens material which does not damage the endothelium. It is possible that similar damage also plays a role in causing abdominal adhesions through contact with rubber gloves, as well as venous thromboses and urethral strictures.


Prevention of postoperative ocular hypertension by prostaglandin inhibitors.

The Pneumatonometer of Langham was used to monitor intraocular pressure in the operating theatre and in the early postoperative period after cataract surgery. Both indomethacin and aspirin were shown to prodcue a significant reduction in the acute ocular hypertension which can be expected to follow 6 hours after routine cataract surgery. It is suggested that the inhibition of prostaglandin synthesis by these drugs is probably responsible for this effect.


Treatment of rhegmatogenous detachment without apparent holes.

In a series of cases of retinal detachment without visible holes, failure was not associated with local procedures but, as in all cases of retinal detachment, with membrane formation and retinal fibrosis. In total detachments with no localizing signs we favoured the encirclement procedure. In this group of thirty cases of retinal detachment in which no hole could be found we achieved the surprisingly high success rate of 87 per cent, but in as many as seventeen of the thirty cases a local buckle was applied to the most likely site of the tear. We therefore feel that the principle of performing the least traumatic procedure, i.e. a local procedure, can still be followed in a considerable number of these challenging cases.


Corticosteroids in the management of herpetic eye disease.

The discriminate use of topically applied corticosteroids to modify or abolish the inflammatory response in herpetic stromal keratitis, has, as its objectives, the prevention of visual loss from corneal scarring and disorganization and a lessening of the morbidity associated with this disese. Steroids may be expected to have a profound anti-inflammatory effect in antibody-complement mediated inflammation and are effective in delayed hypersensitivity as in homograft rejection. The equally profound effect of pharmacological vasoconstriction may enable steroids to impede both afferent and efferent pathways in an immunological reflex arc, and they may be expected to reduce inflammation of nonimmunogenic origin. The adverse effects of the misapplication of these potent drugs in herpetic keratitis, in terms of an increase in the rate of complications and in the severity and morbidity of the disease, should be emphasized again.


Prospects of prevention of recurrent herpetic eye disease.

Various theories of recurrence of herpetic disease are outlined to indicate the potential role that interferon, interferon-inducers, or a hypothetical perfect synthetic antiviral may have in preventing recurrences, and the possibilities of minimizing trigger effects are considered. Attention is drawn to certain aspects of the management of herpetic eye disease that have a direct bearing on the incidence of subsequent recurrence. There is a need to initiate a movement to mobibize ophthalmologists everywhere to educate general practitioners in order to restrain them from harmfully using steroids in undiagnosed red eyes.


[Morphological and histoenzymatic characteristics of the bone marrow in the blastic crisis of chronic myeloleukosis].

Morphological and histoenzymatic characteristics of bone marrow in blastic crisis of chronic myeloleukemia are presented. Its involvement is proved to be irregular even within the limits of small topographic zones. The later is of importance in establishing the diagnosis of the disease by trepine biopsies in hematological practice. The histoenzymatic analysis of the cells in blastic crisis, indicates low degree of their differentiation reaching presumably the level of committed elements of hemopoiesis.


[A study of cerebral autonomic attacks with special reference to sympathetic hyperactivity (author's transl)].

The present paper deals with cerebral autonomic attacks, in particular the ergotropic forms. The clinical symptoms associated with these forms of attacks are described. A multichannel recorder was used for the synchronous recording of various neurophysiological parameters such as ECG, pulse form and psychogalvanic reflex. It is shown that the polycrotic pulse form is characteristic hyperactivity of the sympathetic nervous system with the hypertonic, as well as the hypotonic forms of manifestation. Cases with epileptic fits and those with non-epileptic forms of attacks, as well as "mixed forms" are discussed. The diagnostic significance of these investigations is pointed out and the therapeutic consequences hinted at.


Penetration of ions from silicate cement restorations into Copalite--covered cavity walls.

This study aimed to asses the effect of silicate cement on Copalite -covered cavity walls in extracted human teeth. Class V cavities were prepared in 24 premolars and filled with silicate cement (Bio-Trey). Four cavities were unlined, the rest of the cavities were lined with 1 or 2 layers of Copalite before insertion of the restorations. After 6 months, 70-100 microns thick longitudinal sections of the teeth were studied by polarized light microscopy, microradiography and electron probe microanalysis. When imbibed in water or quinoline, a subsurface zone of altered birefringence was noticed in nearly all cavity walls. Nearly half of the cavity walls in the experimental groups showed a surface zone of increased radiopacity. In a few instances a subsurface radiolucent zone was present. By electron probe microanalysis F (0,4-3% by weight), Zn (1-4%) and Al (0,2-6%) were measured in the outer 10-60 microns of the cavity walls. The study shows that even with a double layer of Copalite, known to prevent microleakage, a desirable uptake of F and Al from silicate restorations into cavity walls can take place. Copalite does not prevent a phosphoric acid effect on the cavity walls.


Chewing efficiency and state of dentition. A methodologic study.

Chewing efficiency, defined as the ability to grind a certain portion of a test food during a given time, was tested in 139 Skolt Lapps, ages 14-65. 94 persons had natural teeth and the remaining 45 wore dentures (partial and/or complete). The test food was almonds. Number of chewing strokes, swallowings and chewing time was denoted. The chewing efficiency was classified after a scale from 1 to 5 where 1 meant very good and 5 very poor ability to reduce the particle size of the test food. Clear associations were found between chewing efficiency and dental state. Number of occluding pairs of teeth was closely correlated with chewing efficiency and individuals with less than 20 teeth had a higher index score than those with more than 20 teeth. The values noted for number of chewing strokes, swallowings and chewing time were smaller for those with a good chewing efficiency, but the variation was not linear and not always significant. Denture wearers had statistically significantly higher chewing efficiency score than those with natural teeth, without dentures, and needed more chewing time before swallowing.


Stress/strain behavior of some dental luting cements.

The compressive strength, modulus of elasticity and the plastic strain at fracture have been studied for several dental luting cements. Stress/strain diagrams of cylindrical specimens using two different crosshead speeds (2 mm/min and 0.1 mm/min) at 23 degrees and 37 degrees C showed that large differences existed between various luting cements. A zinc phosphate cement exihibited high strength, high modulus of elasticity and a small plastic strain at fracture. A resin cement also had high strength, but elastic and plastic strains were high. A polycarboxylate and an EBA-cement both showed low values of strength and modulus of elasticity combined with a high degree of plastic deformation at fracture. Testing with low strain rate at 37 degrees C accentuated the differences between these two materials and the zinc phosphate cement.


Histochemical, ultrastructural and functional evidence for a neurogenic control of cerebrospinal fluid production from the choroid plexus.

Histochemical studies have shown that the rabbit choroid plexus receives a well-developed adrenergic and cholinergic nerve supply. The adrenergic innervation, which orginates almost entirely from the superior cervical sympathetic ganglia, begins to develop around birth and is fully established 3 weeks later. Electron microscopy has shown that the nerve terminals innervate both the plexus arterioles and its secretory epithelium. The sympathetic fibres have been shown to influence the plexus epithelium, as reflected by their effect on its carbonic anhydrase activity. They appear to have an inhibitory effect on the bulk CSF production, as revealed by electrical nerve stimulation and denervation experiments. The control seems to be excerted primarily on the plexus epithelium, though some of the effect may also be associated with alteration in choroid plexus blood flow.


Electrophoretic properties of esterases in chronic granulocytic leukemia.

Granulocytes were obtained from samples of peripheral blood of five patients who had untreated chronic granulocytic leukemia, and polymorphonuclear leukocytes were isolated from peripheral blood of three normal persons. Specific and nonspecific esterases were extracted from leukocyte preparations with cetyltrimethylammonium bromide and with lysolecithin, and subjected to polyacrylamide disk electrophoresis. In samples from both patients and normal persons, electrophoretic patterns of nonspecific esterase activity using alpha-naphthyl acetate and alpha-naphthyl butyrate were similar, and the esterase bands were weakly inhibited by fluoride. Lysolecithin extracts of specific esterase showed similar electrophoretic patterns for patients and normal subjects. However in cetyltrimethylammonium bromide extracts of specific esterase, 11 bands were seen in preparations from all of the patients with chronic granulocytic leukemia. In preparations of normal polymorphonuclear leukocytes, only eight bands were visualized. The results are consistent with an interpretation that these fast-moving components of specific esterase in chronic granulocytic leukemia granulocytes are present in normal polymorphonuclear leukocytes, but in quantities too small to be visualized with the technics used. Alternatively, the apparent "additional" bands of specific esterase may reflect abnormal metabolism of malignant granulocytes in chronic granulocytic leukemia.


[A new ventilator: the Monaghan 228 (author's transl)].

Application of fluidic elements in ventilator technology has resulted in the development of mechanical ventilators for the use in the therapy of acute respiratory failure. We have tested a new apparatus of this type, the Monaghan 228, in the technical laboratory and in clinical use. The results of this study can be summarized as follows: the technical performance of the Monaghan 228 is comparable to that of sophisticated electrically powered and controlled ventilators. The delivered tidal volume remains quite constant with variations of the opposing resistance and with the application of positive end-expiratory pressure. The differences between set and delivered oxygen concentrations do not exceed 4.5% at different tidal volumes. The ventilator has been used in a surgical intensive care unit during the last two years. More than 100 patients have been treated for a total of over 500 days. Clinical experience leads us to conclude that the Monaghan 228 is a versatile, reliable ventilator which can be used for a wide spectrum of diseases requiring mechanical ventilation.


Prevalence and survival of microbial contaminants in heated nebulizers.

Over a 2-year period, 600 cultures of fluid in heated nebulizers in use by patients in the Peter Bent Brigham Hospital were performed. The most commonly isolated microorganisms were Pseudomonas and Alcaligenes species. Pseudomonas aeruginosa was never isolated. Three types of heated nebulizers were in use, and their contamination rate was significantly different (45 percent, 21 percent, and 8 percent, respectively; p less than 0.001). In the course of the study, the overall contamination rate decreased from 47 percent to 10 percent. This was mainly due to elmination of the type of heated nebulizer that was most prone to contamination. Five types of currently available large-reservoir nebulizers were inculated with various organisms and growth patterns studied. The various nebulizing equiment differed in its ability to inhibit or eliminate microbial growth; 1 of the heated nebulizers appeared to enhance growth of some of the inoculated bacteria.


Vocal cord closure. A cause of upper airway obstruction during controlled ventilation.

Studies of vocal cord function were undertaken in a quadriplegic patient requiring ventilatory assistance, and in 2 normal subjects during controlled ventilation in a tank-type respirator. When the patient and the normal subjects relaxed and made no conscious effort to assist the respirator, the vocal cords were observed to close during inspiration and a large pressure gradient (12 to 19 cm H2O) developed across the cords. When the subjects made a slight inspiratory effort ("assist" mode), the cords opened widely during inspiration. There were large increases in flow and tidal volume in the "assist" mode compared with passive ventilation. Measurements of transdiaphragmatic pressure and esophageal pressure showed that these variables did not increase with the slight assist. Thus, increase in ventilation during the "assist" mode appeared to be due to alleviation of inspiratory obstruction at the level of the vocal cords. The same phenomenon was observed in the patient during phrenic nerve pacing. A pacemaker was designed to be triggered by the electromyographic impulse from an accessory muscle of respiration. In this manner, vocal cord opening could be coordinated with the mechanical assist given by the phrenic nerve pacer.


Acquired hemoglobin H in refractor sideroblastic anemia. A preleukemic marker.

Two patients with idiopathic refractory sideroblastic anemia (IRSA) were found to have acquired hemoglobin H. Both developed leukemic syndromes. Six other patients with IRSA had normal hemoglobin electrpohoretic patterns, and none has developed acute leukemia in up to five years. We suggest that hemoglobin electrphoresis be performed routinely in IRSA. The finding of hemoglobin H in this population may be a relatively frequent occurrence and may serve to distinguish the preleukemic patients from those not destined to develop leukemia.


Therapeutic angiography. Its value to the surgical patient.

Standard angiographic techniques formerly used exclusively as diagnostic modalities have been modified to serve as definitive or adjunctive therapeutic measured. The techniques include transcatheter embolization; infusion of vasoactive drugs, chemotherapeutic agents and radioactive particles; tamponade of bleeding arteries and balloon catheters; extraction of vascular foreign bodies and retained biliary tract stones and transluminal arterial dilation. These techniques have been proved effective and safe when used judiciously.


The combined approach to cancer therapy in cancer centres.

In the complex field of cancer therapy the cancer centre approach may be seen more clearly by division of its structure into vertical and horizontal components. Vertically, there are numerous special consultative clinics in types of cancer usually associated with a body region (lung, breast, melanoma, etc.). Horizontally, there are teams of specialists (surgeons, radiotherapists, solid tumour chemotherapists), in some clinics supplemented by haematologists, immunologists, and endocrinologists, providing a wide therapeutic spectrum. Working together in a particular consultative team, the specialists are clinical oncologists, but without the summed wisdom and expertise of the group, the members are more accurately designated individually as specialists in the field from which they spring, for example, thoracic surgeon, haematologist, radiotherapist, and so on. The team approach lends itself to full exploitation of all the centralized sophisticated cancer machinery, be it in the form of equipment like cell-trifuges and linear accelerators, a range and depth of cancer monitoring aids, or a medical record system aligned to a computer, with consequent immediate and long-term therapeutic gain to patients. For the State there is greater efficiency and hence economy. In teaching, the aggregation of all matters relating to cancer therapy presents enhanced opportunities for training of technicians and scientists and nurses as well as doctors, for postgraduate instruction, and for continuing education. For progress in understanding cancer, it is clear that clinical research in conjunction with the combined approach in cancer centres can be conducted with sufficient numbers of patients to give statistical credence to clinical trials.


Hyperthermia and cancer.

The effects of heat and its possible significance in cance therapy have been documented for more than a century. Hyperthermia has been widely investigated as an alternative or adjuvant to conventional therapies such as surgery, radiation, and chemotherapy. The clinical reports are interesting, notwithstanding some harmful side effects and other complications which, however, may be attributable to an advanced stage of the disease at the time of treatment. In view of the extreme difficulty in matching suitable controls for cancer patients undertaking such therapy, it is essential to extend knowledge of the effects of hyperthermia on normal and neoplastic tissue by experimental studies. Further, the different methods of utilizing heat therapy have need for substantial technological improvements. To stimulate interest in this area, we have gathered together in this review some of the more pertinent reports on the application of hyperthermia to neoplastic and normal tissues as observed clinically and in the laboratory.


The consultant surgeon and mammography.

It is important that the mounting wave of criticism of mammography in breast screening programmes should not obscure the fact that it remains the most accurate method of diagnosing breast cancer short of biopsy. Furthermore, breast cancer may be diagnosed by mammography at an early stage before it has spread to regional lymph nodes, at a time when the prognosis is better. At this time it may be beneficial to outline the role of mammography as an aid to the consultant surgeon in the management of patients referred with breast problems.


Psychosocial aspects of head and neck cancer surgery.

Thirty-six patients who underwent major surgical excision and reconstruction for head and neck cancer were subjected to a psychosocial assessment in hospital and, later, in their home environments. The information gained from the survey is discussed, with particular reference to those factors which can be used by the head and neck surgical team to improve the quality of the patients' existence.


Gliomas of the optic nerve and chiasm in children.

This paper reviews the clinical features, management, and prognosis of patients with gliomas of the optic nerves and chiasm who have received treatment at the Royal Children's Hospital, Melbourne, between 1954 and 1977. The relationship of this tumour to other neoplasms in the region is discussed, and emphasis is placed on the natural history of the disease. The controversy concerning the exact nature of this lesion is summarized, and an attempt is made, in the light of this evidence and from the reviewed series, to formulate an appropriate overall plan of management of these patients.


The cavernous sinus: an anatomical survey.

An anatomical survey of the cavernous sinus in 16 adult cadavera has been made, based on serial sections cut at 15 micron in the coronal and sagittal planes. Certain aspects of the survey are of particular interest: (1) the oculomotor, trochlear, and ophthalmic nerves do not run in the lateral dural wall of the cavernous sinus; (2) venous sinuses of the cavernous sinus flow freely in a medial direction both anterior and posterior to the dorsum sellae; (3) trabeculae in the form of collections of fine areolar tissue extend between the vascular and neural elements. The amount present is variable; (4) the horizontal section of the internal carotid artery within the cavernous sinus runs a variable course in relation to the hypophysis and the lateral dural wall; (5) the oculomotor nerve lies within a meningeal envelope as far anteriorly as the tip of the anterior clinoid process; (6) the ophthalmic nerve communicates with the oculomotor, trochlear, and abducent nerves in the anterior part of the cavernous sinus; (7) the abducent nerve may lie within a meningeal envelope in the posterior part of the cavernous sinus; (8) the greater part of the sympathetic nerve plexus around the vertical part of the internal carotid artery passes into the abducent and ophthalmic nerves. Sympathetic fibres pass into the sheaths surrounding the oculomotor and trochlear nerves. Sympathetic ganglia are suspended from the ophthalmic nerve.


The creation of artificial subcutaneous arteriovenous fistulas in patients with malignant haematological disease.

Creation of an artificial subcutaneous arteriovenous fistula was attempted in five patients with malignant haematological disorders (two with Hodgkin's disease, two with acute lymphatic leukaemia, and one with acute myeloid leukaemia). The average time from the start of treatment to attempted creation of the fistulae was four years. Neither direct arteriovenous anastomosis nor an interposition mandril graft was successful in any patient. Failure was attributed to impaired venous run-off secondary to previous episodes of thrombophlebitis induced by the intravenous administration of cytotoxic drugs. The use of an arteriovenous fistula early in the course of the disease might minimize these later problems.


Guidelines for planning clinical trials.

This paper outlines the necessary steps involved in setting up and administering a clinical trial. The importance of adequate preparation, with careful definition of priorities and objectives, is emphasized. Guidelines for writing a clinical protocol are discussed in detail, as well as aids to deal with the running of the study, statistical planning, and presentation of results. The principle of different types of study, methods of patient assessment, and an overall plan of study, have already been introduced in the preceding paper.


Sequential antitumour immunoreactivity and carcinoembryonic antigen levels as a guide to prognosis in colorectal carcinoma.

Twenty-five patients with colorectal carcinoma were tested for blood-lymphocyte anti-tumour cytotoxicity and carcinoembryonic antigen (CEA) levels at three-monthly intervals for eighteen months or more after resection, and examined clinically every three to six months. Twelve of the patients were followed for two years and one for four years. The six patients whose tumours recurred showed positive blood lymphocyte antitumour cytotoxicity and elevated plasma CEA levels at some time from six months after operation, usually well before the recurrence was clinically detectable.


The modulation of tumour-versus-host response in lung, colon, and breast cancer patients: implications for adjuvant immunochemotherapy.

Major advances in the understanding of clinical tumour biology occurred with the appreciation that tumour-associated substances circulated in the blood of cancer patients. In this study their origin and immunogenic function have been investigated. Whole tumour cells (WTC) and cancer cell membrane fractions (CMF) of 24 patients with lung, colon, and breast cancer were investigated for their antigenic effect upon the patients' own lymphocytes and upon healthy allogeneic ones. The antigenicity of whole lung and breast cancer cells to stimulate lymphocyte DNA synthesis, and the ineffectiveness of colon cells were confirmed. CMF had little stimulating effect upon autologous lymphocytes; however, they were able to augment lymphocyte response to PPD and PHA in high dilution and to suppress it in high concentration. The serum of cancer patients exerted similar biphasic activity upon PPD and PHA stimulated lymphocytes ("lymphosuppressive-stimulatory factors", or LSSF). Sephadex studies confirmed that LSSF activity in cancer serum correlated with circulating CMF. These substances modulate lymphocyte nucleic acid synthesis in vitro; it is likely that they similarly modulate the patient tumour-host cell relationship.


Bypass surgery for obesity.

Failure of conservative methods of control of gross obesity has led to the adoption of surgical measures. In our experience intestinal bypass, though resulting in significant weight loss, is associated with a number of unpleasant complications. For this reason our programme now involves the use of 90% gastric bypass. The results in our first 39 patients undergoing this operation are presented, with a six-month to three-year follow up. Weight loss has been satisfactory. Although it is a more major procedure than intestinal bypass, the lack of major metabolic sequelae makes gastric bypass the more acceptable form of management.


Acute acromioclavicular joint dislocation: results of operative treatment with the Bosworth screw.

The results are reported in 21 patients who had acute acromioclavicular joint dislocation treated by open reduction and Bosworth screw fixation, with an average follow-up period of ten years. Nineteen patients had a good or excellent functional result. Good cosmetic results were obtained. Full recovery of shoulder movement occurred in all patients but one, although coracoclavicular calcification was a frequent finding. Complications following this technique were few.


Primary hyperparathyroidism presenting as spinal cord compression: report of a case.

A report of a case of primary hyperparathyroidism presenting as spinal cord compression due to a brown tumour of the vertebra is presented. Coexisting chrondrocalcinosis illustrates one of the several radiological features seen in hyperparathyroidism.


Spinal epidural abscess in pregnancy.

A case of spontaneous epidural abscess occuring in a pregnant woman is reported. Some delay in diagnosis occurred. Decompression resulted in prompt recovery and improvement of a mild neurological deficit.


A method of closed intramedullary nailing of the fractured tibia.

This paper describes a method of closed intramedullary nailing of the tibia, which has now been used in 30 cases, and is simple, quick, and efficient. It requires one additional fitting to the standard orthopaedic table, and the instruments used for an ordinary closed intramedullary nailing of the fractured femur.


A simplified kidney preservation system: the use of hyperosmolar perfusates for continuous perfusion preservation of canine kidneys.

Since the quality of renal preservation following simple ice storage is improved by the use of hyperosmolar washout solutions, hyperosmolar perfusates were evaluated for continuous perfusion preservation. Canine kidneys were preserved for 48 hours by continuous perfusion at 5 degrees C, using hyperosmolar cryoprecipitated plasma and 5% albumin perfusates of osmolalities 397 to 430 mOsm/kg H2O. Hyperosmolar plasma gave significantly better preservation than isosmolar plasma, but the results were only marginally superior to those already obtainable with isosmolar albumin solution. No further improvement in preservation by albumin perfusion was obtained with the hyperosmolar formulations. Because isosmolar albumin solution is easier to prepare than hyperosmolar cryoprecipitated plasma and gives comparable results, it remains our perfusate of choice for continuous perfusion preservation.


The dilemma of stage III breast cancer: a study of preoperative radiotherapy.

The results of treatment of 68 patients with Stage III breast cancer treated by preoperative radiotherapy and subsequent mastectomy have been compared with those in 68 patients treated by more conventional methods, matched individually for age, stage, and year of treatment. Preoperative radiotherapy delayed the time of the first local recurrence, but did not improve overall survival. It is concluded that preoperative radiotherapy may be justified in patients with Stage III breast cancer in an attempt to control local disease, but is unlikely to improve control of systemic recurrence.


Evalution of mechanical ventilators in a hyperbaric environment.

Four mechanical ventilators, the pneumatic Emerson, IMV bird, Urgency bird, and the Modified Mark 2 bird were tested in a hyperbaric chamber at depths up to 165 ft of sea water (FSW). All failed except the Emerson, which is the only machine recommended for chamber use at this time.


A simple system for administering intermittent mandatory ventilation (IMV) with the Oxford ventilator.

A circuit has been devised enabling intermittent mandatory ventilation (IMV) to be delivered from an Oxford ventilator. Two methods for delivering oxygen to the system are described. The circuit is constructed from inexpensive components and only one oxygen flowmeter is required. No modifications to the ventilator are necessary.


Congenital hypoplastic anemia (Diamond-Blackfan syndrome) terminating in acute myelogenous leukemia.

A 31-yr-old female with congenital hypoplastic anemia (Diamond-Blackfan syndrome) whose long course terminated in acute myelogenous leukemia is described. In contrast to Fanconi anemia, malignant transformation rarely occurs in congenital hypoplastic anemia. This patient's diagnosis of congenital hypoplastic anemia is supported by her clinical course, absence of renal abnormalities, a negative family history for hematologic disorders, normal chromosome studies, failure of her skin fibroblasts to transform in culture with SV-40 virus, macrocytic erythrocyte indices, erythrocyte enzyme studies, and bone marrow findings. Only two other cases of malignancy have been reported in patients with congenital hypoplastic anemia. The development of malignancy in these patients suggests that malignant transformation may be a concern in the long-term progression of congenital hypoplastic anemia.


[Delivery of a normal child after chemotherapy of acute promyelocytic leukaemia during pregnancy (author's transl)].

Upon chemotherapy with daunorubidomycin and cytosinarabinoside, a patient suffering from acute promyelocytic leukaemia during the 28. week of pregnancy achieved complete haematological remission. In spite of complicating disseminated intravascular coagulopathy and aggressive chemotherapy a normal child was delivered by cesarian section during the 34. week of pregnancy. Specific problems in the treatment of acute leukaemia during pregnancy are discussed.


Leukostasis associated with blood transfusion in acute myeloid leukaemia.

Three patients with acute myeloblastic leukaemia and blast cell counts greater than 100 X 10(9)/1 (100 000/mm3) died unexpectedly soon after blood transfusion. In two cases postmortem examination disclosed cerebral leukostasis. Analysis of the records from the MRC's fourth and fifth acute myeloid leukaemia trials showed that in the first week after diagnosis mortality was five times greater in patients with blast counts above 100 X 10(9)/1 than in patients with lower counts. Age and platelet count did not explain this excess. The mean haemoglobin concentration in the patients with high blast counts who died within the first week was 10.5 +/- 2.8 g/dl, which was significantly higher than that in the surviving group (7.6 +/- 2.4 g/dl). Only half the patients received chemotherapy within two days of diagnosis. Leukostasis is an important cause of early death in patients with high blast counts, and the increase in viscosity produced by transfusing to a haemoglobin concentration above 10 g/dl may lead to sudden deterioration. Transfusion to such concentrations should be avoided until the blast count has been reduced by early chemotherapy.


Effects of hypothalamic lesions on the food intake of the goldfish (Carassius auratus).

Goldfish were trained to perform an operant in response in order to obtain food, thereby allowing the food intake to be accurately determined. The normal daily food intake was established for each fish before it was given a sham operation or bilateral hypothalamic lesions. It was then observed over a period of up to 60 days. Lesions of the lateral areas of the hypothalamus were found to cause cessations of operant feeding of up to 60 days duration, and cessations of feeding on manually presented food of up to 35 days. Lesions of the anterior-medial areas were followed by cessationsof operant feeding of up to 26 days. The post-lesioning food intake of fish lesioned in the posterior-medial area was similar to that of the control fish. No increases in operant feeding were observed after lesioning. The results are considered to be consistent with a genuine aphagia induced by lesions of the lateral hypothalamus.


Atypical chronic myelogenous leukemia with Philadelphia (Ph') chromosome and an additional translocation.

A case of chronic myelogenous leukemia in which the disease pursued an atypical course is described. The presence of a previously unreported translocation t(1;20), in addition to a Ph' chromosome t(9;22), is demonstrated, and its possible significance and relationship to the disease are discussed.


Echocardiography in adriamycin cardiotoxicity.

Twenty-six patients receiving adriamycin for osteogenic sarcoma had serial echocardiographic assessments of their left ventricular function. A statistically significant deterioration of function was noted throughout the course. Ventricular function tended to normalize in the period following cessation of adriamycin. The velocity of circumferential fibre shortening (Vcf) and ejection fraction (EF) were the best parameters. Sudden declines in these values resulted in us withholding therapy until the parameters again improved. Fatal congestive heart failure was seen in only one patient. Echocardiography thus provides the clinician with a valuable tool enabling one to improve the therapeutic usefulness of adriamycin by removing much of the uncertainty over the development of cardiotoxicity.


Simultaneous presentation of acute myelomonocytic leukemia and multiple myeloma.

A patient with acute myelomonocytic leukemia and multiple myeloma occurring simultaneously prior to initiation of chemotherapy is described. Possible mechanisms for this occurrence are discussed.


Transepiphyseal extension of osteosarcoma: incidence, mechanism, and implications.

Forty-five cases of osteosarcoma were studied for transepiphyseal spread of the lesion because of the current interest in local resection and chemotherapy as treatment of this disease. In 17 cases, the epiphyseal plate had closed and all 17 had transepiphyseal extension of the tumor. In 28 cases, the epiphyseal plate was open; 21 showed growth or microscopic evidence of transepiphyseal extension of the lesion. The most common method of extension was directly through the epiphyseal plate along vascular channels, or less commonly, about the epiphyseal plate beneath the perichondrium and into the epiphysis along the epiphyeal vascular channels. The majority of these extensions were not detectable by either conventional radiography or radioisotope scanning. Local resection with preservation of the epiphysis will, in all likelihood, leave residual disease despite the oft-quoted statement that an open epiphyseal plate is a biologic barrier to the extension of bone tumors.


Disseminated intravascular coagulation in childhood acute lymphocytic leukemia with poor prognostic features.

Three children with ALL having poor prognostic features developed clinical and laboratory evidence of disseminated intravascular coagulation (DIC). Two developed a bleeding diathesis associated temporally with a rapid drop in blast cell counts during induction therapy with L-asparaginase, prednisone, and vincristine. One of these children died of massive cerebral hemorrhage. The third patient developed episodes of superficial thrombophlebitis associated with relapses and rising blast cell counts which responded to chemotherapy and treatment with heparin. The unusual association of ALL with DIC and the fact that all 3 patients had multiple poor prognostic signs have led us to monitor carefully the coagulation system and withhold L-asparaginase in patients with massive disease until the white cell count and organomegaly have responded to prednisone and vincristine. The more common association of DIC with non-lymphocytic leukemia and recent reports of the presence of the Ph' chromosome in children with leukemia morphologically resembling ALL suggest that chromosomal evaluation be done in selected leukemic patients.


Clinical prognostic factors in osteosarcoma.

Clinical characteristics thought to be of prognostic importance for patients with osteosarcoma are reviewed. The importance of considering prognostic factors in the evaluation of new therapies when no concurrent control group is available is emphasized.


Surgical treatment of osteogenic sarcoma at the Mayo clinic.

Osteogenic sarcoma continues to present a tremendous therapeutic challenge. Until recently, treatment has continued at a relatively unsophisticated level. Although amputation, usually at a cross-bone level with a safe margin above the lesion, continues to be the treatment of choice, increased interest is being demonstrated in radical en bloc limb-saving resections. Modern joint implants are proving effective in restoring the osseous integrity and joint function after the resection.


A simple method to increase the FDO2 of resuscitator bags.

Four resuscitator bags were studied to see if the delivered fractional oxygen percentage (FDO2) could be affected by manually controlling the inherent reexpansion rate of the bag so as to allow a greater entrainment of oxygen rather than air into the bag. Flow rates of oxygen into the bag were varied: 5, 10, 15, and 20 liter/min. For each flow rate, bag refill (reexpansion) times were varied: 1, 2, 4 sec. The results show that such a maneuver will effectively increase the FDO2 of the bags at all flow rates tested--in certain instances to values greater than 0.8. This maneuver would be important to resuscitation situations where it is desirable to achieve better patient oxygenation.


A portable, low cost ventilation system for transportation of patients with severe acute respiratory failure.

As part of the development of a life support stretcher for transportation of critically ill patients, a portable ventilation system was developed. This system was used successfully during transportation of 6 of 11 patients who required ventilatory assistance and who were being considered for extracorporeal membrane oxygenator support. Immediately after transportation, PaCO2 values were significantly lower (p less than 0.05) in patients ventilated with this system, when compared to PaCO2 values of the remaining 5 patients in whom ventilation was assisted with a 2-liter anesthesia bag (PaCO2 = 58.7 +/- 3.6). This system offers significant advantages over other presently manufactured systems, including low cost, portability, and efficiency in terms of oxygen utilization. (Manual ventilation is supplied so that no auxiliary electrical power supply is necessary.) Positive end-expiratory pressure (PEEP) can be varied by 2.5 cm H2O increments using a commercially available, weighted ball valve. In addition, it has been useful for transporting patients with acute respiratory failure within the hospital for therapeutic maneuvers or diagnostic studies.


A method of maintaining sterility of heated humidifiers in mechanical ventilator breathing circuits.

Using the standard MA-1 breathing circuit, the Cascade Heated Humidifier and tubing become rapidly contaminated with patient organisms. The rapidity with which this occurs seems to depend on the quantity and quality of patient secretions and dumping infected water from lazy loops into the Humidifier. Following modifications to the ventilator circuit which included: (1) closed system humidifier filling, (2) the addition of a small copper trap and drainage system to the inspired side of the breathing circuit, and (3) alteration of the heater, no contamination of the humidifier contents occurred for periods as long as 28 days. This trap was manufactured in our hospital using standard plumbing fixtures; a commercial model is available. This system is applicable to any volume ventilator using a heated reservoir humidifier.


[Diploid radiation-induced gynogenesis in carp. II. Segragation according to morphological traits in gynogenetic progenies].

The character of segregation in diploid gynogenetic progenies of Cyprinus carpio with respect to the following three external characters was studied: the type of scale cover, the colour and the design. The genetic formulae of these characters are as follows: the type of scale cover: scaled--(Snn); scattered--(ssnn); linear--(S--Nn); nude--(ssNn); the existence of design (D--); the absence of design--(dd); the type of colour: light--(LI); dark--(II). The dominant genes N and L exert a recessive lethal effect. For the loci N--n, D--d and L--l a conspicuous prevalence of dominant form was established. Linear and nude carps constituted 98%, light carps--85% and carps with a design--also 85% of the total number of gynogenetic descendants. The proportions of heterozygotes Nn, Ll and Dd were 97.3, 73.9 and 70.0% respectively. The frequencies of descendants dominant and recessive for the locus S--s proved to be closely similar: 52.4% (S--) and 47.6% (ss)the proportion of heterozygotes Ss being 4.8%. The data on the frequency of gynogenetic heterozygotes suggest the existence of a high positive interference in the carp. The value of the latter for the four loci studied, the genetic distance between each of these loci and "its" centromere was determined. The data obtained are discussed.


Chromosome abnormalities and clinical and morphologic manifestations of chronic myeloid leukemia.

Forty cases of chronic myeloid leukemia (CML) were studied and subgroups of cases with similar chromosomal abnormalities in terminal stage were defined. Certain correlations were observed between the type of chromosomal changes, and clinical and morphologic manifestations of the disease: (1) It seems that, in cases without any karyotype changes other than translocation (9;22), the terminal stage is longer and milder than in cases with additional chromosomal abnormalities; (2) cases with marker i(17q) are clinically and morphologically rather uniform and are characterized by distinct signs of myeloid differentiation of blast cells, absent in other cases; (3) in cases with various atypical chromosomal abnormalities, the course of the terminal stage is the most rapid and grave. The blast cells differ from myeloblasts and resemble lymphoid elements.


Waste of dental pain.

The effects of dental disease on the population are difficult to describe to the lay public in terms which that public will appreciate. An attempt has been made to quantify the impairment of the quality of life which results from uncontrolled dental disease. Studies indicated that each person could have three to four days of dental pain a year which could be equivalent to 200 million days of toothache per year in the United Kingdom. Only 15 per cent of those who had toothache did seek dental advice for it. This represented a waste and an impairment in the quality of life. It is proposed that estimates of days of dental pain could prove an index of the quality of life of a population.


Cell adhesion.

Before cells can adhere to a surface, the atoms forming the adhesive bonds must come to within 0.5 nanometers of each other. Distances of this order may not correspond to the averaged electron micrographic data. The events leading to close approach of parts of cells are discussed in terms of electrical parameters, with an emphasis on the surface heterogeneities of cellular adherends. The distinct phenomenon of cell detachment is not simply the reverse of cell adhesion, and must be measured by different techniques. The effects of various pathophysiologic factors on cell attachment and detachment is discussed, with illustrative examples of direct and indirect factors. These include regeneration, degeneration, metabolic inhibitors, endotoxin and antisera. It is concluded the stability of the union between cells and teeth represents a delicate balance between factors promoting contact and initial adhesions, factors strengthening the adhesive interphase and factors promoting separation.


Adjunctive orthodontics in oral rehabilitation.

This paper encompasses a few of the more common indications for adjunctive orthodontics. It is by no means a complete list, but relates to those problems often seen in restorative practice and readily handled by the trained restorative clinician. A multitude of techniques exist for the accomplishment of any of the objectives discussed above. The choice of method to be utilized lies with the aptitude of the clinician concerned. It should be noted that, irrespective of the method used, some form of stabilization will be essential on completion of the tooth movement.


A comparative study of panorex and periapical radiographs for evaluating caries and periodontal disease.

Since large lesions were detected easily in both methods, it is felt that for longitudinal studies of periodontal disease in large populations the panorex with two posterior bite-wing films has the following advantages: 1. Allows recording of the entire dentition, alveolar bone continuity and surrounding structures, beyond comparison with the periapical technique. 2. Has fixed head position and alignment factors which facilitate standardization. 3. Simplicity of operation requiring minimal time and effort. 4. Low radiation exposure.


Effect of sodium fluoride rinsing on dental plaque accumulation.

1. Daily rinsing with water does not prevent plaque accumulation and leads to increased levels of gingival inflammation. 2. Toothbrushing or mouth rinsing with sodium fluoride alone decreases plaque accumulation and improves gingival health. 3. The combined method (toothbrushing and rinsing with sodium fluoride) is the most effective. Confirmation of the above results and conclusions requires additional experiments carried out over a longer period of time.


Sex-linked genes in age-structured populations.

We study the progress towards equilibrium of the frequencies of sex-linked genes in elementary discrete time models of age-structured, overlapping generation populations. It is found that, if a finite upper age limit is assumed, the difference in the frequencies of an allele in males and females will oscillate as in the familiar non-overlapping generation models, although the oscillations may be irregular. Monotonic convergence of that difference, as found by Nagylaki (1975) in continuous-time overlapping generation models without age-structure, occurs in the models considered here only when there is no upper age limit and when there is "sufficient" overlap of generations.


A simple ventilator suitable for respiratory gas studies.

A simple ventilator is described where a spring-loaded bellows is filled from a compressed gas supply. The outflow from the bellows to the subjects is controlled by solenoid valves. The device is a minute volume divider and the durations of inspiration and expiration are set by timers that operate the solenoid valves. The valves are positioned near the subject to minimize dead space and gas compression effects. Precise valve timing ensures separation of inspirate and expirate. The ventilator is suitable for respiratory gas studies on animals and may be modified for human use if required.


Bone marrow fibrosis in acute lymphoblastic leukaemia of childhood.

A prospective study of bone marrow fibrosis was made in a group of 40 children with acute lymphoblastic leukaemia to see whether it affected the prognosis or course of the disease. Secondary myelofibrosis (SMF) was present at diagnosis in 57% of the cases. It was not statistically significantly related to the prognosis or course of the disease. Thus, although trephine biopsy occasionally provided useful information in different diagnosis and when aspiration was difficult, it provided little information of use for management.


Antibody formation and cell-mediated immunity to dog pulp tissue altered by N2 paste via the root canal.

1. N2 paste when incubated with dog pulp tissue renders it antigenically active. 2. Specific systemic circulating antibody to dog pulp tissue altered by N2 paste was obtained. 3. When dog pulp tissue was altered by N2 paste a specific lymphocyte stimulation resulted. 4. The root canal is an effective mode of immunization.


Diffusion phenomena during artificial carious lesion formation.

Artificial carious lesions were produced in human enamel using lactic acid [HL] buffers plus diphosphonate [MHDP]. Surface layer thickness was related to [MHDP], middle zone (body) and inner zone depths to [HL] and pH. Indications are that diffusion in enamel is predominantly by unionised species such as HL and CaHPO4, and dissolution by H+ and L-.


Erythroplasia: the earliest sign of asymptomatic oral cancer.

This prospective study was conducted to determine the significance of erythroplasia (red) versus leukoplakia (white) in the diagnosis of asymptomatic oral carcinoma and to accurately record the appearance of the erythroplastic lesion. Persistent asymptomatic lesions in any portion of the oral cavity, except the lip, that were considered clinically suspicious with our previous criteria (erythroplasia), or those changes that did not correspond to the visual criteria but were found in high risk sites, were studied and biopsies were performed. Degrees of redness versus whiteness and clinical diagnoses were documented. Of 148 lesions in 113 patients, 66 were malignant (52 invasive and 14 in situ). There was a false negative diagnostic rate of 4.5% (3 of 66) and a false positive rate of 7% (4 of 57). Of the malignant lesions, 86.3% were primarily red compared with 31.9% of the benign lesions. OF the cancers, 10.7% were predominantly white as opposed to 66.7% of benign lesions. This analysis confirms our previous suppositions that persistent erythroplasia rather than leukoplakia, in high-risk sites of the oral cavity, is the earliest and predominant sign of oral carcinoma.


An inquiry into the sterilization of dental handpieces relative to transmission of hepatitis B virus.

The transmission of the hepatitis B virus has been implicated in the dental office. The dental profession should be keenly aware of aseptic clinical techniques and effective sterilization procedures. Some dental handpieces can be damaged by conventional sterilization procedures. Alternative procedures are discussed. A review of currently available handpieces and their appropriate sterilization procedures is presented.


Oral exfoliative cytology.

Oral exfoliative cytology can be a powerful tool for early detection of malignant and premalignant lesions as well as for some viral and fungal infections, if the limitations of the method are thoroughly understood and appreciated by the dental clinician. The rationale for oral cytology is developed and documented, and interpretations of the results are explained. Advantages and disadvantages of this technique are given and indications and contraindications for this diagnostic adjunct are discussed. A simple method involving the use of inexpensive equipment in the office is suggested.


Aspects of illness behavior in patients with facial pain.

Results of recent studies have suggested that factors other than clinical signs and symptoms have a significant role in determining whether people seek treatment for perceived facial pain and mandibular dysfunction. The concept of "illness behavior" can be used to investigate this problem. Knowledge of a patient's illness behavior patterns helps enable the dentist to understand who seeks care for symptoms of facial pain and mandibular dysfunction; why the care is sought; the meaning of the symptoms to the patient; and the patient's response to treatment.


Human pulpal response to citric acid cavity cleanser.

Treatment of cavities with citric acid cavity cleanser, also used as an etchant, before restoration with zinc oxide-eugenol cement, was toxic to the human dental pulp in comparison to sham-treated controls. The cleanser caused a significantly (P less than .01) greater intensity and incidence (P less than .01) of inflammation. The added insult from cleanser pretreatment caused destruction of the odontoblast processes withnin the cut dentinal tubules, and an increase in diameter of the tubules. These effects on dentin and odontoblasts probably contributed to the observed increase in adverse pulp responses.


The effect of sodium trimetaphosphate (TMP) as a chewing gum additive on caries increments in children.

A three-year study on school-age children using trimetaphosphate as a chewing gum additive produced significant reductions in proximal surface dental caries increments as compared to an non-chewing gum group. The reductions were 23.3% for the TMP sucrose gum group and 47.6% for the TMP nonsugar group as compared to the no-gum group.


An evaluation of electromyographic biofeedback in the treatment of myofascial pain-dysfunction syndrome.

Electromyographic (EMG) biofeedback was used in a controlled situation to teach patients with myofascial pain-dysfunction syndrome to relax and masseter muscle. Those receiving biofeedback were able to reduce their mean masseter EMG levels significantly. Concurrently, there was a reduction of symptoms. Seventy-five percent of the successfully treated patients required no further therapy during one year of observation.


Aneurysmal atherosclerosis of the inferior labial artery with segmental arteriectomy.

A case of aneurysmal atherosclerosis of the inferior labial artery has been presented in which a segmental arteriectomy was performed to eliminate the possibility of involuntary trauma to the area, which could produce considerable hemorrhage. Psychologicall, the patient felt better by knowing that the mass was completely removed. Atherosclerosis should be considered when masses are found in the lips in elderly patients. It is thought that this lesion is common but has not been reported in the past.


Metallic contamination of bone during drilling procedures.

The influence of drills and burs of different shapes and materials on the amount of metallic transfer was studied. In these experiments, holes were drilled in bone with radioactive tools and the amount of metal transferred to the bone was measured by means of gamma-ray spectrometry. The proportion of the drill material transferred to the bone varied widely, depending on the type of the drill, its previous usage, and on the specific element considered. Most of the drills transfer a few microgram of iron to the bone, together with smaller quantities of cobalt, tungsten, and chromium. The total quantity of material transferred to the bone from new drills exceeded that of old drills. Almost invariably, the second drilling transferred less material than did the first, even with used drills.


Sliding osteotomy in the mandibular body for correction of prognathism.

To overcome some of the disadvantages of the mandibular body ostectomy, a sliding osteotomy accomplished by parallel sectionings of the mandible in the regions of the first premolars was used for the treatment of mandibular prognathism in two cases. The osteotomy was performed by an intraoral approach without any damage to the contents of the mental foramen. The anterior segment could be moved back to any desirable position without losing optimum bony contact. An adequate blood supply to the anterior segment was maintained by a large area of periosteal attachment on the lingual side. The method is effective for correction of mandibular prognathism in which a good occlusion cannot be expected by a ramus osteotomy.


The perimeatal exposure of the condyle.

The perimeatal approach to the condyle provides access to the area of the glenoid fossa by the combination of preauricular and postauricular incisions. Damage to the frontal branch of the facial nerve does not occur because the anterior tissues are not retracted excessively. The cartilaginous meatus is not transected during the operation, which avoids the problem of stenosis of infection of the cartilage.


Huge osteoma of the mandible: report of case.

A review of the literature on osteoma of the jaws as well as its relationship to Gardner syndrome was presented. A case report of a compact or ivory osteoma that had been slowly enlarging for a minimum of eight years was described. The one-year postoperative examination has shown no discernible resumption of growth.


Tuberculous ulcer of the tongue: report of case.

In the case presented, the patient sought treatment for a painful ulcer on the right lateral border of the tongue. In the absence of any other significant finding, the clinical features of the lesion suggested malignancy. Histopathologic examination of a biopsy specimen was an important aid in the diagnosis of tuberculosis. Pulmonary lesions were subsequently detected and the patient was treated accordingly. The ulcer on the tongue was believed to be secondary to the pulmonary tuberculosis.


Systemic tuberculosis initially seen as an oral ulceration: report of case.

A 67-year-old white man was seen for the treatment of a painful oral ulceration. His medical history was highly suggestive of systemic disease. Radiographs of the chest and cultures of sputum were positive for tuberculosis. The incidence, appearance, and characteristics of oral tubercular lesions have been presented. The diagnosis of tuberculosis should be considered along with carcinoma, syphilis, fungal disease, and trauma whenever granulomatous ulcerations appear in the oral cavity.


Subcutaneous parotid effusion after mandibular osteotomy.

A case of subcutaneous parotid secretion after extraoral vertical mandibular osteotomy for prognathism has been described. The possible causes have been discussed and a rationale for conservative management has been suggested.


A simple clamp for stabilization of the mandible during surgery.

There has beeen an unfilled need for a clamping device to stabilize the mandible during certain types of surgery. The instrument described accomplishes this in a very simple and positive fashion.


Mandibular metastasis of an extraskeletal myxoid chondrosarcoma arising on the plantar surface of the foot: report of case.

This paper presented a discussion of the initial appearance and atypical clinical course, histopathology, treatment, and prognosis of a case of extraskeletal myxoid chondrosarcoma that originated on the plantar surface of the left foot and that metastasized to the mandible. The clinical behavior of this neoplasm, as reported, is distinctively less aggressive and therefore thought to have a better prognosis than chondrosarcoma of bone. Contrary to the biologic behavior reported in the literature, however, our patient had a less than six-year remission from the neoplasm.


Computer-graphic representation of mandibular movements in three dimensions. Part I. The horizontal plane.

A computer-graphics simulation was developed to display the effects of mandibular movement patterns of both the maxillary and mandibular teeth in the occlusal plane. The many parameters affecting mandibular movement patterns may be varied selectively. The effects of these parameters on the pathways of movement described by the supporting cusps during occlusion can be graphically observed in the horizontal plane.


Anterior guidance--the key to successful occlusal treatment.

1. The occlusion of the anterior teeth is the key to developing and perpetuating an "ideal" occlusion. 2. The anterior teeth protect the posterior teeth by disoccluding them in eccentric positions, and the posterior teeth protect the anterior teeth by receiving most of the forces of closure in centric position. 3. The anterior guidance is a result of both anterior tooth position and condylar border movements; both factors must be considered in the creation of an anterior guidance.


Microleakage and marginal adaptation of composite resin restorations.

It has been shown that the use of a sealant offers no advantage with respect to the retentive strength of a composite resin restoration. However, for the improvement of marginal seal and adaptation, the present findings indicate that enamel etching and the application of a sealant, in conjunction with use of a cavity geometry which reduces shrinkage strain, are absolute necessities.


Microleakage and enamel finish.

Cavity preparations that are finished with hand instruments allow significantly less marginal leakage than those which are completed only with rotary instruments. This does not mean that hand-instruments walls are perfectly smooth; it only means that these walls allow less marginal leakage. Cavity preparations restored with composite resin showed more marginal leakage than those restored with amalgam. Also, the degree of marginal leakage was greater in cavity preparations restored with composite resin than in those restored with amalgam. Cavity preparations are more prone to marginal leakage at sharply defined cavosurface acute angles than at the smooth or straight surfaces of the cavity. This pattern of marginal leakage was true for both amalgam restorations and composite restorations, but the degree of marginal leakage was greater when composite resin was used as a restorative material. Since less marginal leakage was found in the finished cavity preparations, it is obvious that all cavity preparations must be finished with hand instruments. This may not completely eliminate the problem of marginal leakage, but it will reduce the potential secondary caries both in degree and frequency. Also, since sharply defined acute angles did exhibit more marginal leakage, this part of the cavity preparation needs special attention. With amalgam and composite restorations at least, these angles should not be sharply defined but should be slightly round, so that better condensation of restorative materials can be obtained. This may reduce the degree of marginal leakage.


Punch shear strength of polycarboxylate cements.

Two general conclusions are drawn which apply to all the four commercial polycarboxylate cements: First, the effect of storage condition upon shear strength was much more pronounced after 24 hours than after 1 hour of storage time; second, the effect of storage condition was most extreme when the specimens were tested free of their matrices. Additionally some specific comparisons between the four products tested can be made based on differences of shear strength within the same experimental condition. The effect of confinement decreased in the following order: Boston greater than Bondal greater than PCA greater than Durelon. Sensitivity to storage conditions decreased in this order: Durelon greater than Bondal greater than PCA greater than Boston. Finally sensitivity to storage times decreased in the order Bondal greater than Durelon greater than Boston greater than PCA.


Obturator prosthesis design for acquired maxillary defects.

Fabrication of obturator prostheses does not require a special ability to fabricate a prosthesis extension into a defect or an arbitrary extension of a prosthesis into a defect. Fabrication of an obturator prosthesis depends on the application of basic prosthodontic principles that are used in the treatment of patients without maxillary defects. Some principles must be modified because of the defect and the character and position of the remaining structures. The defect, in conjunction with the remaining structures, must be used to provide support, retention, and stability of an obturator prosthesis. If basic prosthodontic principles are applied the size and extension of the obturator will be determined, and the extensive variation so commonly seen in obturators will be minimized. Acceptable prosthodontic care for the patient with the acquired maxillary defect should include cautious prosthesis design combined with routine maintenance care to provide comfort, function, cosmetics, and minimal change to the compromised remaining structures.


Maximum mandibular opening in patients with and without a history of TMJ dysfunction.

It was shown that there was no direct connection between maximum jaw opening and a history of TMJ symptoms (Fig. 7). An accurate diagnosis requires the evaluation of a wide range of signs and symptoms through both a history and a clinical examination.


One face-bow adapts to three articulators.

A procedure has been described whereby simple adaptors will allow the convenient Whip-Mix Quick Mount face-bow to be transferred to the commonly used Hanau H-2 and Dentatus ARH semiadjustable articulators.


The specificity of the microcytotoxicity assay for cell-mediated immunity in human bladder cancer.

Cytotoxicity of lymphocytes from T1 or T2 bladder cancer patients and patients with other diseases was tested in 44-hour microcytotoxicity assay against 3 different target cell lines: 1) HU 456, derived from human bladder carcinoma and established in our laboratory, 2) HU 609, a line derived from normal human bladder tissue and established in our laboratory and 3) SAOS-2, a human osteosarcoma cell line from the Memorial Sloan-Kettering Cancer Institute. Lymphocyte concentrations ranging from 7.8 time 10(4) to 2.5 times 10(6) lymphocytes per ml. were tested against each cell line. Lymphocytes from both groups of patients demonstrated a cytotoxicity against all 3 target cell lines, proportional to the lymphocyte concentration used. There was no difference in reactivity to HU 609 or to SAOS-2 between bladder cancer and control patients but the lymphocytes of bladder cancer patients showed a statistically greater cytotoxicity for HU 456, demonstrating a tumor type-specific cellular immune reaction superimposed on a background of non-specific cytotoxicity.


Maxillary sinus infection with Allescheria boydii (Petriellidium boydii).

Allescheria boydii (Petriellidium boydii) has previously been described as a cause of Madura foot and pulmonary and other visceral infections. This report describes infection of the maxillary sinus and facial soft tissue with A. boydii in a compromised host. The infection did not respond to antibiotics, including amphotericin B and 5-fluorocytosine. Miconazole was not used in our patient, although in vitro data obtained after death indicated sensitivity of the fungus to miconazole.


Lung resection for metastatic osteogenic sarcoma.

Osteogenic sarcoma, excluding the paraosteal osteosarcoma, has a grave prognosis, half of the patients dying within 1 year following ablative surgery of the primary lesion. Once pulmonary metastasis is detected, most patients do not survive more than 3 years. Various attempts by investigators to prolong patient survival, including surgery, chemotherapy, immunotherapy, radiation therapy, and combined modalities, have met with some success. This report is a summary of 13 patients who underwent lung resections and received adjuvant chemo- and/or immunotherapy for metastatic osteogenic sarcoma in our intstitute in the past 7 years.


Oliguria and its sequelae.

Fifty-nine patients were seen with oliguria in 1975. Forty had acute renal failure (ARF) and 19 rapidly reversible oliguria (RR). The causes of the oliguria were medical (64%), surgical (27%) and obstetrical (9%). The following were valuable in the assessment of patients with oliguria: urine sodium concentration (UNa) and osmolality, coagulation studies and high dose intravenous urography. Patients presenting with a high UNa or a coagulation abnormality were more likely to have ARF. Central venous pressure monitoring was helpful in the initial management but the administration of diuretics was not. Twenty patients with ARF were treated conservatively and the remainder by dialysis. Infection was both the commonest complication of ARF and the most frequent cause of death. Seventy percent of those with ARF died. Death was more common in the elderly or patients with a medical aetiology. The mortality of ARF remains high in spite of advances in the management of its metabolic and infective complications because of the acceptance of more high risk patients. An improved awareness of the preventable causes of oliguria is apparent.


Maori abortion practices in pre and early European New Zealand.

The practice of abortion and infanticide in pre and early European New Zealand is confirmed. The reasons for these practices and the methods used are discussed in relation to early Maori attitudes and mythology.


Pain and pain relief in labour.

In a survey of 50 women delivered consecutively in a modern maternity hospital, 45 suffered severe and/or very severe pain. This followed an average of just over five hours of mild or moderate pain, and lasted for an average of 3 1/4 hours, in spite of pain relief. Intramuscular pethidine, which tended to be given late in labour, was notably ineffective in relieving pain. Epidural analgesia was highly effective, but was used in only 10 patients, and after an average of 5 1/2 hours of severe or very severe pain. A majority of primiparas found the pain more severe or much more severe than they had been led to expect, and only 34% of the sample were "quite happy" about their next labour, with regard to pain. It is suggested that there is room for improvement.


The Christchurch Hospital diabetes education programme.

The Christchurch Hospital diabetes teaching programme is now well established and towards the end of 1977 the results of an evaluation programme should be available. Our aim is to give diabetics and their families the best possible education and to stress the importance of patient self-sufficiency. Patient feedback methods are used to encourage continuing education. The assessment of the value of the educational programme warrants considerable attention and suitable methods of evaluation are being attempted.


The nutritional status of New Zealanders with respect to manganese, copper, zinc and cadmium--a review.

The information currently available for assessing the manganese, copper, zinc and cadmium status of New Zealanders was reviewed. By comparison with current standards the status of manganese and zinc in New Zealanders appears to be adequate and the body burden of cadmium is low. The Cu status of some New Zealanders could be inadequate.


Subacute ectopic pregnancy.

A series of 90 patients with 98 ectopic pregnancies is discussed, emphasising problems of diagnosis. Predisposing factors and evidence of previous pelvic pathology were not uncommon. Laparotomy was considerably delayed in 31 patients, 15 of whom required two admissions before definitive treatment. There was one death in the series. An accurate history is most important. In doubtful cases, direct inspection of the pelvic organs is the only sure way of excluding ectopic pregnancy. Laparoscopy allows this, yet will save a laparotomy in a number of cases.


The virus of hepatitis B a new dimension in the diagnosis of sexually transmitted disease.

Ten patients presenting with venereal or dermatological disorders have been found to have evidence of infection with the virus of hepatitis B; only five had distinguishable liver dysfunction, yet all had either detectable antigen or antibody. Antigen subtype ayw has been identified in four of these people. Once rare in the local population, hepatitis B virus infection appears to be increasing in incidence with cases attributable to inoculation and to direct contact, as well as presenting as a covert partner to gonorrhoea, urethritis and candidiasis. Testing for hepatitis B antigen and antibody is recommended for patients attending the venereal diseases clinic, for patients presenting for removal of tattoos, for those with suspected drug taking and for Polynesians, in whom the carrier rate may be expected to be high (Austin and others, 1974). In our current clinical practice the sterilisation of instruments, the handling of patients, and the transmission of specimens to the laboratory have been reviewed in the light of the US Public Health Service supplement 1976, Perspectives on the Control of Viral Hepatitis, Type B.


Pre-hospital trauma management.

Pre-hospital trauma care and management in the United Kingdom, West Germany, Denmark, the United States of America, Australia and New Zealand, are briefly compared. An analysis is presented of 738 serious motor vehicle accidents attended in Canterbury from November 1972 until February 1977, showing that the accidents with life threatening conditions commonly occurred more than 20km from the base hospital.


A trial of live virus intra-nasal influenza vaccine.

One hundred and fifty-seven medical students were randomly divided into three groups: one group was vaccinated with ALICE live virus intra-nasal vaccine; one with sub-unit vaccine given subcutaneously and the third group with a placebo intra-nasal vaccine. One hundred and four patients from two group practices were also given ALICE vaccine by one of four different practitioners. Sero conversion occurred to an equivalent extent in all those given ALICE vaccine and there was only a minor increase in the sero-conversion rate following a second dose of vaccine. Protection by the ALICE intra-nasal vaccine against the A/ Port Chalmers strain of influenza appeared to be superior to that of sub-unit vaccine and HI antibody titres persisted longer in the ALICE group than in those subjects given the sub-unit vaccine.


Clinical use of plasma renin assays.

The use of plasma renin assays in clinical practice is reviewed and experience with an assay for plasma renin activity (PRA) is reported. In normal subjects, 10am ambulant PRA was significantly related to plasma angiotensin II levels but not related to daily urine sodium exretion in these subjects consuming normal diets. PRA was suppressed in patients with mineralocorticoid hypertension and in a small proportion of patients with essential hypertension. Very high values were observed in patients with untreated primary adrenal insufficiency, treatment of which resulted in a prompt fall of PRA to normal. PRA was usually normal in adrenalectomised patients and those with chronic adrenal insufficiency receiving satisfactory steroid replacement therapy. It is concluded that provided standardised conditions are used for the collection and assay, PRA is helpful in the assessment of hypokalaemic hypertension as well as in the early detection and management of patients with primary adrenal insufficiency or related conditions of salt wasting.


Weights and heights of Fijians from coastal and inland villages.

Heights, weights and nutrition indices are presented for an inland dwelling population of Fijians surveyed in 1961. The results are contrasted with those for coastal dwelling Fijians and the conclusions drawn that coastal dwellers were taller and heavier and suffered more obesity and less malnutrition, than inland dwellers. The differences were not great.


Sisomicin in the treatment of severe or complicated urinary tract infections.

Sisomicin is a new aminoglycoside aminocyclitol antibiotic with pharmacological similarities to gentamicin and tobramycin. Fourteen of 24 patients with a severe or complicated urinary tract infection were cured by treatment with a 4-14 day course of sisomicin. In three patients the organism was not eliminated, in one there was a relapse with the same organism while in the remaining six patients a new pathogen (a gram-positive organism in five of these six) appeared within three to six days of completing the course of treatment. The initial infecting organism was therefore eradicated in 20 of the 24 patients treated. This drug should prove beneficial for the treatment of severe gram-negative sepsis.


A technique for investigating the intensity and duration of human psychomotor impairment after intravenous diazepam.

The objective of this study was to evaluate the impairment of both psychomotor function and memory after intravenous administration of 17 to 28 mg. of diazepam to normal volunteers. A battery of tests, including word memory, Seguin form board, digit symbol, digit span, block design, and reaction time, was administered at set intervals to both drug and nondrug subjects. The diazepam group demonstrated both psychomotor and anterograde memory deficits which persisted throughout the 150-minute evaluation; but relative to the control group, the diazepam group had enhanced retrograde memory. These preliminary results indicate that even after subjects appear to be recovered from the effect;s of diazepam, residual psychomotor and memory impairment remain.


Central giant-cell lesion in the mandibular condyle. Report of a case.

Giant-cell lesions of the temporomandibular joint are rare. In the present case a central giant-cell lesion of the temporomandibular joint is described, and the distinction between central giant-cell reparative granulomas and giant-cell tumors is discussed. Successful reconstruction of the temporomandibular joint by means of an 8 cm. costochondral graft in an elderly patient with a central giant-cell lesion of the mandibular condyle is also reported.


The management of the oral complications of leukemia.

Current management of the oral complications of leukemia has been reviewed by means of a questionnaire circulated to leukemia units in Great Britain. Oral manifestations of the disease appear to be common and symptoms severe despite advances in the general management of this group of diseases. It is confirmed that infection involving a wide variety of commensal organisms is an important problem, and it is suggested that improvements can be made in management, especially with the use of broad-spectrum antiseptic agents (for example, 0.2 per cent chlorhexidine gluconate which reduces the total number of organisms in the mouth by about 98 per cent.).


Experimental endocarditis induced by dental manipulation and oral streptococci.

Circumstantial evidence has strongly implicated dental manipulation as an etiologic factor in the development of infective endocarditis. The introduction of human oral streptococci via the oral cavity in rabbits with vegetative cardiac lesions yields a 94 per cent incidence of infective endocarditis, if the number of inoculated organisms is above a threshold level of 10(7).


The correlation between organoleptic mouth-odor ratings and levels of volatile sulfur compounds.

An organoleptic rating (OR) technique and gas-liquid chromatography were employed to study the relationship between oral-malodor ratings and the corresponding concentrations of oral volatile sulfur compounds (VSC) in a total of 102 subjects in two separate studies. Both studies demonstrated a statistically significant positive correlation between the intensity of perceived oral malodor and the concentration of VSC (H2S + CH3SH) emitted by individual subjects.


Squamous-cell carcinoma of the floor of the mouth.

This study was based on the analysis of 100 cases of squamous-cell carcinoma of the floor of the mouth. The male/female ratio was 4.25:1. The peak incidence in women was in the 50 to 59 year age group; in men there was equal frequency in each age group above 50. The five-year survival rate decreased from 86 per cent to 0 as the stage of disease progressed from I to IV. The five-year survival for all stages of disease was 52.7 per cent. Thirty-three per cent developed new primary malignancies; 22 per cent were of the upper alimentary and respiratory tracts. Distant metastases were present in 21 per cent. Fifty per cent were heavy smokers, 33 per cent were heavy drinkers, 28 per cent were both heavy smokers and heavy drinkers, and 21 per cent were nonsmokers and nondrinkers.


Clear-cell sarcoma of tendons and aponeuroses.

The natural history and histologic characteristics of a rare malignant neoplasm of tendons and aponeuroses are described, and a case is presented which originated in the right foot of a 19-year-old Caucasian woman who succumbed to the disease after 4 years. This case represents the first known example of metastasis to the oral cavity of this particular neoplasm.


Intraoral juvenile xanthogranuloma.

A case of juvenile xanthogranuloma of the gingiva is presented. This uncommon, benign disorder has rarely been histologically documented in the oral cavity, and rarely have oral lesions been described as presenting symptoms prior to this report. The pertinent literature is reviewed and possible etiologic factors are discussed.


Sjögren's syndrome (sicca complex).

A case of sicca complex Sjögren's syndrome in a 41-year-old woman is presented. Symptoms related to xerophthalmia and xerostomia were severe but, ironically, served to confuse the clinical impressions of medical personnel managing this patient, resulting in a diagnostic dilemma. Biopsy of a labial minor salivary gland followed by histopathologic examination of the tissue provided invaluable information which, together with the clinical picture, aided in the establishment of the delayed diagnosis.


Oral assessment of the "risk" patient.

Certain patients may be considered as being at "risk" with respect to the possibility of development of significant diseases of either a local or a systemic nature as a direct result of the presence of oral infection. The problems relating to the development of bacteremia subsequent to surgery in the patient with cardiovascular disease are well appreciated. Thought should be given to the possibilities of such developments in relation to the presence of periapical pathosis. It is demonstrated that a definitive evaluation of the status of the nonvital tooth cannot be made by the presently accepted methods of clinical and radiographic examination.


Endodontic therapy averting major surgery and avoiding keloid formation.

Keloids and mandibular unfavorable fractures are reviewed. A case report of a patient with keloid diathesis, who had a mandibular unfavorable fracture, is presented. A grossly carious, abscessed first molar was in the line of fracture. This tooth was the only erupted tooth present in the proximal fragment. Endodontic therapy and restoration of normal contour enabled the surgeons to treat the fractured mandible by means of simple closed reduction. The endodontic treatment pre-empted a major surgical procedure under general anesthesia and also averted a skin incision which would have subsequently formed a disfiguring keloid.


Compensation of differences in density of radiographs by densitometry.

Radiographs were made of a dried human mandible with variations in kilovolt peak, exposure time, soft-tissue thickness substitutes, and developing time. The densitometric measurements of the image of dental and bony structures were transformed into millimeters of aluminum equivalents by means of densitometric measurements on the penetrometer. Variations in kilovolt peak, exposure time, soft-tissue thickness substitutes, and developing time do not affect the densitometric measurements after transformation, except when radiographs are very dark.


Lesions resembling caries in unerupted teeth.

Two cases are presented documenting the recognition and treatment of defects in the coronal portion of unerupted mandibular second permanent molars. The teeth were surgically exposed and the lesions treated as deep pit and fissure caries. Small, vital pulp exposures were encountered in both cases. Calcium hydroxide was placed and restoration with amalgam followed. Normal root formation and eruption occurred for 24 and 6 months, respectively. A firm diagnosis of caries, external resorption, or internal resorption could not be made because of the lack of histologic study.


Bony defects in dried Bantu mandibles.

Forty-three dried South African Bantu mandibles were examined visually and radiographically for the frequencies of occurrence of apical defects, bifurcation involvements, dehiscences, and fenestrations. Statistical evaluation of the data revealed no significant discrepancy between the visual and radiographic findings.


Uric acid metabolism in therapy of glycogen storage disease type I.

Factors which may explain lower serum uric in a new therapy of patients with glycogen storage disease (GSD) type I have been studied. [1-14C]Glycine incorporation into urine uric acid was 0.68% of the injected dose during a 6-day period of frequent high carbohydrate feedings, 0.40% with the same diet and nocturnal nasogastric feeding by Vivonex, and 0.18% in a control patient with GSD type III. Fractional renal uric acid excretion in the patient with GSD type I increased from 11.3% to 26.3% after beginning nocturnal nasogastric feeding of Vivonex. Red cell phosphoribosylpyrophosphate leve,ls were not changed by the therapy. Addition of Vivonex nocturnal feedings to frequent high carbohydrate feedings (1) decreased the accelerated de novo purine synthesis to a level still higher than control and (2) increased fractional renal uric acid excretion.


[Interviews with Norwegian dentists about continuing education].

A representative, nationwide sample comprising 50 dentists in Norway was surveyed through personal interviews concerning their opinions on and need for postgraduate education. The reports clearly indicated that the professional challenges are changing rapidly as a result of improved treatment habits and dental health among most patients and that continuing dental education should adjust to the new situation. Most interviewers were satisfied with the courses presently offered, but they nevertheless wanted more of them, particularly in oral medicine and surgery, prosthetics, prevention and community dentistry. Scientific papers abounding with statistics and histology were suggested to be reduced in the Norwegian Dental Journal, and should be replaced by practical review papers. Social motives for attending professional meetings were common, the dentists said they learned much of practical value and picked up news in conversations with colleagues. Improved contacts with the dental schools was desired. Concerning undergraduate education, a prevailing view was that too much time was devoted to basic sciences as opposed to clinical- and community dentistry. The attitude towards compulsary continuing education was ambiguous, conceivably a reflection of the two different professional ideals: high standards and autonomy.


[Prolonged survival in 16 cases of acute myeloid leukemia [author's transl)].

16 our of 370 acute myeloid leukemias treated between 1964 and 1973 have been in long survival for more than three years. In the first period 1964-1971 the overall remission rate was 20% and 6 patients has a long survival. In the last two years of study, 10 out of 96 patients have more than three years of survival, the remission rate was over 50%. All the cases were slightly proliferative the first group did not recieve intensive chemotherapy and appear as spontaneous long remission, but in thelast patients intensive chemotherapy seems responsible for the good results.


[Respiratory function tests during artificial ventilation. Application in the choice of apparatus settings (author's transl)].

Twenty seven patients on artificial ventilation were studied in terms of gas exchange, respiratory mechanics and haemodynamics. The characteristics of acute respiratory failure (dead space effect, shunt effect, disturbances in respiratory mechanics) may be identified and their severity determined. The effects of adjusting artificial ventilation settings (tidal volume, frequency, inspiration/expiration ratio, inspiratory flow, end expiratory pressure, inspired oxygen fraction) may be studied and better adapted to the individual functional requirements of each patient. An organigram of settings based upon the experience gained in this series is suggested.


[Leukaemias and lymphomas treatment by vindesine. Result of a phase II trial in terms of remission induction (author's transl)].

Vindesine is a derivative of vinblastine and of vincristine. A high proportion of remissions were obtained in acute lymphoid leukaemia (6 complete and 1 incomplete remissions in 15 patients), in blastic crisis of chronic myeloid leukaemia, and a few responses have been registered in lymphosarcoma and Hodgkin's disease. Permanent 48 h i.v. infusion may include a remission where i.v. pusch of the same dose has failed. The most remarkable characteristic of vindesine is the absence of cross-resistance with vincristine as documented in acute lymphoid leukaemia.


Ion flow through a membrane: concentration and current responses to a step potential change.

Solutions of the simplified time-dependent Nernst-Planck electrodiffusion equations for various membrane models under the influence of a step voltage change are presented. Comparison of the results for a membrane with continuous sites to those for membranes with two, three or five intermediate sites shows little difference either qualitatively or quantitatively in the concentration of the diffusible ion inside the membrane, although some quantitative differences are evident in the calculated currents.


Theoretical study of protein--lipid interactions in bilayer membranes.

An analysis is given for the perturbation of the order and composition of lipid bilayers near an intrinsic membrane protein. Two cases are examined: the protein influences the lipid order (i.e., "fluidity"), and the protein associates with one component of a lipid mixture preferentially. The order perturbation is studied as a function of temperature and lateral pressure by using Landau--de Gennes theory and a variational procedure. It is concluded that, for a given lateral pressure, the greatest amount of boundary lipid is present at the lipid phase-transition temperature. A critical point for the phase transition occurs, near which the amount of boundary lipid increases dramatically. The composition perturbation is modeled in a binary lipid mixture by using a simple regular solution theory. The perturbation is found not to extent much beyond the directly bound layer of lipids unless the solution is near a critical mixing point.


Unique structures formed by pyrimidine-purine DNAs which may be four-stranded.

Pyrimidine-purine DNAs with repeating sequences can be made to undergo a reversible transition to possibly a tetra-stranded complex. Physicochemical characterization of the new structures and model building are consistent with, in the case of d(TC)n-d(GA)n, a tetra-stranded complex forming by the addition of d(GA)n to the remaining space in the major groove of the triple-stranded complex d(TC)n-d(GA)n-d(CT)n. A possible role for tetra-stranded complexes in chromosome condensation is suggested by the natural occurrence of repeating sequence pyrimidine-purine DNAs and the properties of condensed chromosomes.


Mapping of adenovirus late promoters with nascent mercurated RNA.

Nascent RNA molecules were labeled in vivo and elongated in vitro by incubation of the isolated nuclei in the presence of mercurated nucleotides. The RNA molecules initiated and labeled in vivo and elongated in vitro were then selectively purified on a thiopropyl 6-B Sepharose affinity column. The procedure was shown to be free of artifacts since the addition of mercurated nucleotides and the retention on the affinity column is mediated by the endogenous RNA polymerase II (nucleoside triphosphate:RNA nucleotidyltransferase; EC 2.7.7.6), is sensitive to actinomycin D, and is dependent on the presence of all four ribonucleotide triphosphates. This general procedure was applied to the mapping of viral promoters late after adenovirus 2 infection of HeLa cells. RNA purified as described above was hybridized to restriction enzyme fragments attached to nitrocellulose filters. The 5' ends of the nascent RNA chains are located in coordinates 9.5-17 for a rightward transcript, 0-25 for a leftward transcript, and possibly 60-70 for a second rightward transcript. These locations clearly differ from locations of the early promoters and therefore suggest that the transition from early to late functions is controlled at the transcriptional level.


Characterization of the histone core complex.

A stable histone core complex containing equimolar ratios of H2A, H2B, H3, and H4 has been isolated from chicken erythrocyte chromatin in high salt. This complex has been characterized by sedimentation and chemical cross-linking studies. In velocity ultracentrifugation, only one single sharp sedimentation boundary has been observed with sedimentation coefficient S020,w = 3.8 +/- 0.1. The molecular weight of the histone core complex has been investigated by low-speed sedimentation equilibrium studies over a wide range of protein concentration. Analysis of the apparent weight-average molecular weight as a function of concentration indicates that the histone core complex in 2 M NaCl, pH 9.0, is in equilibrium between a tetramer (H2A)(H2B)(H3)(H4) and an octamer [(H2A)(H2B)(H3)(H4)]2 species with a tetramer molecular weight of 55,000. The equilibrium constant K is approximately 1.2 X 10(-5) liter per mol at 10 degrees. Evidence of such a tetramer-octamer equilibrium in solution is also supported by the results of our chemical crosslinking experiments on the histone core complex.


Strand-specific break near the origin of bacteriophage P2 DNA replication.

Membrane-associated P2 DNA isolated early after infection under conditions that block replication (amB in phage and rep in Escherichia coli C) was analyzed by electron microscopy. Most DNA was in the form of relaxed circles (40%) and circles with short single-stranded tails (60%). When this DNA was hybridized with separate strands of linear P2 Hy dis DNA (which provides suitable reference points along the heteroduplex molecules), an interruption was located near the previously mapped origin of P2 DNA replication in one specific strand. The same strand was sometimes extended in the direction consistent with the unidirectional mode of P2 DNA replication. Similar conclusions were reached when the intracellular DNA was analyzed after partial denaturation. These results are consistent with the rolling circle mode of DNA replication.


Noncovalent interaction of the NH2-terminal fragment of human somatotropin with the COOH-terminal fragment of human choriomammotropin to generate growth-promoting activity.

Complementation of the plasmin fragments of reduced-carbamoylmethylated (Cam) human somatotropin (hGH) with those of reduced-carbamoylmethylated human chorionic somatomammotropin (hCS) have been investigated. It was found that the recombinant obtained by noncovalent interaction of [Cys(Cam)53]hGH-(1-134) with [Cys(Cam)-165,182,189]hCS-(141-191) exhibits 50% growth-promoting activity and nearly full immunoreactivity. Complementation of [Cys(Cam)53]hCS-(1-133) with the COOH-terminal fragment of hGH generated lower growth-promoting and immunological activities.


Acetylcholine-receptor-mediated ion flux in electroplax membrane microsacs (vesicles): change in mechanism produced by asymmetrical distribution of sodium and potassium ions.

The kinetics of acetylcholine-receptor-mediated efflux of inorganic ions from electroplax microsacs of Electrophorus electricus in the presence of varying alkali metal ion concentrations on both sides of the membrane have been investigated. The efflux, a monophasic process when the ion distribution is symmetrical (the same concentrations and types of ions on both sides of the membrane), becomes a biphasic process, consisting of a very rapid initial release of ions followed by a slower first-order process, under conditions that resemble the physiological state of the neural membrane (potassium ions inside the microsacs and sodium ions on the outside). The initial phase of the efflux discriminates between calcium and sodium ions and is inhibited by potassium ions in the external solution. The rate constant associated with this phase is at least 40 times larger than the rate constant associated with the slower efflux. Both phases depend on the concentration of acetylcholine or carbamoylcholine, and are inhibited by receptor inhibitors (d-tubocurarine and alpha-bungarotoxin).A simple model is proposed which relates the kinetics of the flux to ligand-induced conformational changes in the receptor. We also indicate the relationship between the biphasic kinetics of the flux observed in microsacs to "desensitization," the phenomenon in which, on addition of acetylcholine, the transmembrane voltage of muscle and nerve cells first increases and then decreases to its resting value within a few seconds.