[Evolution of the pulp chamber and pseudodentin in the selachians the Brazilian coast (suborder Galeoidea). Morphological study]. The author made a morphological study of Selachii (Suborder Galeoidae) of the Brazil coast using ground sections. Dental structures undergo modifications as one studies species of different evolutionary stages. The lower Selachii have an osteodentine nucleus which suffer alterations until it disappears leaving a pulp chamber in its place. The layer of pseudodentine shows modification too. It consists of pseudodentine in lower Selachii but its modifications are such that in higher Selachii (Sphyrnidae, for instance) one may suppose it is made of orthodentine. Based on these and other published data the author concludes that the degree of evolution of the pulp chamber and pseudodentine allows the establishment, with great probability, of the phylogenitic position of the Selachii within the Galeoidea Suborder.


[Ultrastructure of the alveolodental ligament of the rat]. The ultrastructural study of periodontal ligaments of adult rat molars showed that the predominant cellular element consisted of fibroblasts and fibrocytes. These cells were responsible for the elaboration of the collagen precursors and for their destruction as was demonstrated by the presence of ellipsoidal intracytoplasmic vacuoles containing collagen. The abundance of microfilaments and microtubules as well as the presence of intermediary and tight junctions and nexus between the cell processes seemed to indicate that these cells are contractile and motile. Other cell types were intrequent. The ligament presented a high density of collagen fibrils grouped in bundles. Oxytalan fibrils were also observed. The blood capillaries showed mainly a continuous endothelium. Numerous myelinated and non-myelinated nerve fibrils, as well as nerve endings and mechano-receptors were identified.


[Bacterial accumulation on silicate and composite materials]. It was shown in a previous study that more plaque accumulates on composite filling materials than on silicate cement and amalgam. The purpose of the present investigation was to compare the accumulation of Streptococcus mutans on silicate cement and on composite material by scanning electron microscopy. Whether the adhesion was dependent on the presence of sucrose was also tested. Round disks, 6 mm in diameter, were made from the two materials. The disks were submerged in media with and without sucrose and inoculated with S. mutans OMZ 176. The disks were removed after 1 or 30 minutes, rinsed in saline and prepared for SEM. Along the diameter of each disk pictures were taken at similar intervals. From a total of 48 pictures from each material 18 pictures were selected at random and the number of microorganisms counted. The results indicated that bacteria initially adhered to both silicate and composite in about the same number. The presence of sucrose did not influence the initial adsorption. After 30 minutes bacteria were scarcely found on silicate, whereas large clumps of bacteria were attached to the composite. Sucrose increased bacterial accumulation on composites but did not affect the adherence to silicate cement.


[Topographic distribution of mitosis in the lower incisor and 1st molar in the mouse embryo]. The analysis of serial frontal sections of lower mandibular arches of 14 to 18 days old mice embryos allowed the study of the pattern of mitosis in the incisor and the first molar. A very clear dissociation between the values of the mitotic index of the internal and external dental epithelia was observed. The high mitotic activity of the inner dental epithelium was considered as playing a very important role during the growth of these teeth.


Tongue fissures. A classification and comparative prevalence study among 825 European Caucasian and 605 Xhosa Negro school children. Six distinct patterns of tongue fissuring have been observed: plication, central longitudinal fissuring, double fissures, transverse fissures arising from a central fissure (type "A"), transverse fissures without a central fissure (type "B") and lateral longitudinal fissures. Some tongues exhibited more than one pattern. There was a significant correlation between double fissures and central longitudinal fissuring (P less than 0.002) but not between other forms of fissuring. No significant relationship was found between the occurrence of atrophic lesions and the prese-ce of fissuring. Significant differences were found between the prevalences in Xhosa and Europeans for central longitudinal fissuring, double fissures and both types of transverse fissures but not for plication. No significant differences were found between males and females and in the age distribution for those with and those without each type of fissuring. It is suggested that most tongue fissuring seen in children should be considered variations in normal anatomy rather than an abnormality.


Influence of amalgam, alloy, and Hg on the in vitro growth of Streptococcus mutans: III. Effect of specimen age and composition. We will now summarize the conclusions from parts I, II and III of this study. A test procedure has been developed that provides a simple, quick, and nondestructive means of monitoring the in vitro growth of S mutans in the presence of amalgams and alloys. The spectrophotometric readings are related in a simple way to growth expressed as dry weight of bacteria and metabolic products. Results are expressed as growth relative to controls which represent bacteria growing under identical conditions but not in contact with metals. The %RA60 value that represents growth after 60 hours relative to controls is used as a measure of growth in the presence of alloys or amalgams. Spherical, fine cut, and dispersion alloys were studied as well as amalgams prepared from these alloys. The dispersion alloy inhibits growth less than the spherical alloy which in turn inhibits growth less than the fine cut alloy. The results for amalgams prepared from the alloys are reversed. At an aging time of two hours, dispersion alloy amalgams inhibit growth more than spherical alloy amalgams and fine cut alloy amalgams. Aging time of amalgams greatly influences the growth inhibition. Immediately after trituration growth is inhibited, but this inhibition is lost with aging. Different types of amalgams seem to lose growth inhibition at different rates. Hg composition in the range of 48 to 52% seems to have little effect on growth inhibition. It remains for clinical studies, which are concerned with the incidence of secondary caries associated with amalgams, to demonstrate that the age and nature of the amalgam are significant.


Finite element stress analysis of the crowns of normal and restored teeth. Stress distributions are presented for a normal and a restored mandibular second premolar under masticatory-type forces. These were obtained using the finite element method of stress analysis applied to two-dimensional models. The effect of the relative stiffness of the materials is examined in each instance.


Microprobe analysis of a Au-containing alloy and its amalgam. Under near-equilibrium conditions, an alloy ingot containing approximately 64% Ag, 26% Sn, and 10% Au was found by X-ray diffraction to consist of large grains demonstrating the gamma (Ag-Sn) structure. Microprobe analysis of these grains showed a 64.2% Ag, 25.3% Sn, and 10.5% Au composition with very small amounts of AuSn2 and AuSn4 segregated at the grain boundaries. When this alloy is manufactured in the form of rapidly colled spherical particles, X-ray diffraction shows both beta (Ag-Sn) and gamma (Ag-Sn) structures with Au substituting for Ag, and microprobe analysis demonstrates a segregation of small high Sn, high Au areas having a AuSn2 composition. When Hg is mixed with these spherical particles, gamma1, some gamma2, and Sn-Au phases (AuSn2 and AuSn4) form. The Au that combines with Sn seems to come from the beta or gamma phases rather than from the Sn-Au segregations in the alloy. The small amount of the gamma2 phase that is initially formed apparently disappears after a short period of time although there is some question as to whether a very small amount may still remain. The Ag-Hg hase (gamma1) is essentially the same as found in conventional amalgams as is the small amount of gamma2 initially formed. Furthermore, a nonequilibrium state seems to be necessary for the early and possibly complete elimination of gamma2. In the as-cast condition, after a period of time at 37 C, A Ag-Hg-Sn phase (beta1) is formed that is similar to that found in conventional amalgams that serve as restorations in the mouth for a period of time. However, in the 135-annealed amalgam, no beta1 appears.


Optical method for articulator comparison and study of occlusal determinants. A method of articulator comparison and a technique demonstrating the effects of three occlusal determinants were demonstrated and proved successful. The techniques used could be used in dental research circumstances and in dental schools as a means to study the determinants of occlusion.


Erythrocyte velocity in vascular networks of young noninflamed dog gingiva. Measurements of erythrocyte velocity in vascular networks of noninflamed gingiva of deciduous canines of four young dogs were obtained using vital microscopy and high-speed cinephotomicrography. Mean erythrocyte velocity in small gingival vessels was 1.59 +/- 0.29 mm/sec. Differences in erythrocyte velocity of vessels comprising a gingival microcirculation and of vessels within different gingival samples were not significant.


Surface properties of hydroxyapatite: I. The effect of various inorganic ions on the electrophoretic behavior. The zeta potential of hydroxyapatite (HA) at a constant pH depends on the type of acid used. Fluoride ions increase the charge density and make the surface less prone to attack by acid or alkali. Sn2+ and Th4+ ionic complexes with fluoride ions and increase the uptake of fluoride by HA.


Effects of dietary fats on the fatty acid composition of enamel and dentinal lipids of rabbit molars. The effect of dietary fats such as butter, lard, cottonseed oil, and hydrogenated cottonseed oil on the fatty acid composition of enamel and dentin lipids of rabbit molars was studied. The enamel and dentin of molars of all of the rabbits contained a variety of fatty acids, palmitic, stearic, oliec, linoleic, and eicosapentaenoic being the major ones. Enamal lipids were more unsaturated than dentinal lipids in all of the groups. A significant difference was noticed in the fatty acid composition of both the enamel and dentin between these four groups of rabbits. Linoleic acid content was highest in both the enamel and dentin lipids of rabbits fed cottonseed oil. There was no marked difference in the saturated-unsaturated fatty acid ratio in both the enamel and dentin among rabbits fed cottonseed oil, lard, and butter. It is concluded that tooth lipids are responsive to diets and are in direct equilibrium with dietary components.


Magnesium in bone mineral: an in vitro study. The solubility of magnesium in bone mineral from control and magnesium-dificient rats receiving varying fluoride intakes was assessed. Evidence for the existence of a fluoride-related pool of skeletal magnesium possessing a diminished solubility was obtained.


Calcification of membranes isolated from Bacterionema matruchotii. Lytic cultures of Bacterionema matruchotii were found to release vesicular membranes into the medium which could be obtained virtually free of other cell structures by differential centrifugation. Suspension of the membrane fraction in a metastable calcium phosphate solution resulted in the formation of both amorphous mineral and hydroxyapatite. Examination by electron microscopy showed that mineralization was associated with the membrane bilayers. The results provide further evidence that calcification of B matruchotii is related to intracytoplasmic membranes.


Enhancement of the antiplaque value of antibacterial agents by enamel conditioning methods: III. Animal results. A 1:1 water-paste slurry of a placebo and several experimental dentifrices was swabbed daily for six weeks on the teeth of albino rats, and the plaque collected on the teeth was measured in vivo first before the treatments began and one, two, three, and six weeks after. The results indicate that adding a suitable antimicrobial agent to a placebo dentifrice markedly reduced plaque accumulations on the teeth brushed with that product. When an enamel-conditioning vehicle was used instead of the placebo, the antiplaque effectiveness increased severalfold. It was concluded from the two first articles of this series 1,2 that adding antibacterial agents to enamel-conditioning systems resulted in the incorporation of the antimicrobial compound into enamel treated with these systems, and that enamel treated in such a fashion acquired marked antibacterial properties of its own. The data reported in this article support a third conclusion, namely, that the enamel-conditioning-antibacterial systems have a considerable antiplaque effect in laboratory rats.


Cariostatic activity of calcium glycerophosphate in hamsters: topical vs dietary administration. Two experiments were conducted to determine if calcium glycerophosphate administered continuously in a diet or intermittently as a single daily topical application to teeth had an anticaries potential in young hamsters that were fed a cariogenic diet. The hamsters were inoculated with a caries-conductive streptococcal strain. Within the 60-day experimental period, results of these evaluations indicated calcium glycerophosphate significantly reduces caries when fed in the diet at levels of 1% and higher, and significantly reduces caries when applied topically at levels of 2% and higher. There were no observable differences in plaque formation among treatments.


Identification of the cultivable bacteria in dental plaque from the beagle dog. Fifteen different genera of microorganisms were isolated from the 27-month-old plaque of two beagle dogs. They were as follows: Pseudomonas, Proteus, Neisseria, Escherichia, Staphylococcus, Streptococcus, Lactobacillus, Nocardia, Actinomyces, Corynebacterium, Micrococcus, Microbacterium, Brevibacterium, Arthrobacter, and Kurthia. The dog plaque was characterized by a low number of streptococci and the presence of several noncarbohydrate-fermenting organisms.


Caries experience in deciduous and permanent dentition of the same individuals. Caries of the permanent first molars of 5-year-old children was found to be associated with caries of their diciduous teeth. The sample consisted of 220 children whose permanent first molars had erupted. They were selected out of 965 children who were a representative sample of children attending compulsory kindergartens in Jerusalem, 1971.


Analysis of the dextranase activity produced by an oral strain of Bacteroides ochraceus. An anaerobic, gram-negative, dextranase-producing filamentous bacterium isolated from human dental plaque has been identified as a strain of Bacteroides ochraceus. The inducible intracellular dextran-degrading activities produced by this microoranism can be fractionated into endohydrolytic and exohydrolytic enzymes with distinct pH optima. These enzymes reduce the apparent rate of glucan production from sucrose by the dextransucrase produced by Streptococcus mutans and consequently may influence the in vivo production of polysaccharides involved in plaque accumulation and metabolism.


Examiner standardization for caries studies. Examiners in clinical control programs customarily undergo an intensive period of training to standardize their interpretation of diagnostic criteria. Data are presented summarizing examiner error rates in calibration examinations and reversal rates in a field study.


Estimating examiner consistency with DMFS measures. Within- and between-examiner reliability estimates were considered for standardization data. However, within-examiner stability was demonstrated to be the important measure of examiner consistency in the clinical trial because it directly affects the precision of the study. Finally, an argument is also made against the use of reversal rates in the assessment of examiner consistency.


Evaluation of a simplified caries index for use by the US Army Dental Corps. The evaluation of a simplified caries index was undertaken to determine the validity and reliability of the index when applied to a military population. Although certain internal assumptions of this simplified caries index were not upheld, the index did rank order the populations by severity of caries experience when compared to the DMFS index. High interexaminer and intraexaminer reliability scores were demonstrated.


Standardization of value profiles of dental students and dental faculty. This study used the Allport-Vernon, Lindzey1,2 Study of Values to establish standardized norms for dental populations, and examined the relationship among freshmen, seniors, and full-time and part-time faculty. The normative data indicate that there is a similarity in general patterns for all groups. The dental student population sampled have higher scores on aesthetic and social values than their counterparts ten years ago.


Dental caries experience in the deciduous dentition of rural Guatemalan children ages 6 months to 7 years. A study of 528 Guatemalan children indicated that caries prevalence in the deciduous dentition was twice as great as but in the permanent dentition was similar to that for US white children. This is a repeated observation for children of some preindustrial societies. Caries experience was significantly greater in boys. Until 4 years of age, caries attack was greater in the anterior segment of the oral cavity; linear enamel hypoplasia was a predisposing factor.


Videotape modeling of the child dental patient. One week before their first dental visit, 36- to 60-month-old children were shown a videotape to model their behavior in the dental situation. The behavior was then rated for three visits. The children who had been modeled did not behave significantly better than either children who had no previous contact with the dental setting or children who had visited the reception room one week before their first dental visit.


A new abrasive applicator for human enamel biopsy procedures. Experiments were performed that demonstrated that the felt cylinder usually used to obtain abrasive biopsy specimens did not uniformly remove enamel from rounded or irregular enamel surfaces in the window area. A foam-silicone rubber laminate was developed to replace the felt cylinder. This resulted in greater uniformity of abrasion over the enamel surface within the biopsy window area and better operator handling characteristics.


Measurement in vitro of enamel abrasion by dentifrice. An in vitro method of measuring the abrasivities of dentifrices and abrasive powders on human dental enamel has been developed. The method, based on a proven dentin abrasivity method, records, in absolute terms, the abrasive effects of brushing flat, nonirradiated, enamel specimens beneath an aqueous slurry of the test material with the use of a surface profile meter.


Fluoride deposition in human enamel in vivo from professionally applied fluoride prophylaxis paste. Deciduous teeth were collected from children who received professional prophylaxis with an acidulated phosphate-fluoride (APF) or placebo paste and were analyzed to determine fluoride uptake. Enamel fluoride level was increased by the APF paste approximately 300 ppm at a depth of 2.5 micrometers during the first month after the prophylaxis was administered, after which it returned to pretreatment levels.


Ion probe study of fluorine gradients in outermost layers of human enamel. F concentrations in the outermost layers of human tooth enamel were studied with the aid of a secondary ion microanalyzer. Concentration profiles were recorded in continuous sputtering analysis from the surface down to a depth of about 0.3 micrometer. Samples previously subjected to topical fluoride treatment were compared with reference specimens. In some samples, the results were compared with those obtained at greater depths by macroscopic etching analysis.


Oral health of patients with cystic fibrosis and their siblings. Caries prevalence, oral hygiene index, submandibular gland hypertrophy, occlusion, dental hypoplasia, and staining of permanent teeth were evaluated in 63 patients with cystic fibrosis (CF) who were maintained on a regimen of broad-spectrum antibiotics and oral pancreatin, and the findings were compared with those of their near-aged siblings. Gland hypertrophy and dental staining were increased in patients with CF whereas caries was significantly decreased. No other significant differences were found.


Formation of calcium phosphates in saliva and dental plaque. This is an X-ray diffraction study of the mineral phases in saliva and early dental plaque. The salivas studied came from patients with cystic fibrosis (CF), those with asthma, and heavy and light calculus formers. One-week old plaque was studied from individuals who are heavy, moderate, and light calculus formers.


Utilization of auxiliaries and attitudes of dentists toward the delegation of duties. Employment of auxiliaries by dentists is high and duties performed by those auxiliaries vary. The auxiliaries' years of experience prior to their present job is low, but tenure in the job is not as low since over 30% have been employed five years or more. Regardless of the category of dentists being considered (type of practice, year of graduation, employment of auxiliaries), the great majority of dentists (over 95%) do not think cutting soft or hard tissue should be delegated. Beyond these two procedures, however, the tables show considerable variation in attitude toward delegation when year of graduation and employment of auxiliaries are considered. Other procedures that a substantial portion of the profession does not believe should be delegated are administering local anesthetic agents; placing and finishing resins, composites, and silicate restorations; placing amalgam restorations; and carving and finishing amalgam restorations. The impact of these attitudes on delivery of care should be directed particularly toward the attitudinal differences occasioned by graduation year and employment of auxiliaries, since the proportion of graduates shifts regularly and employment of auxiliaries is increasing.


Comparison of interproximal carious lesion detection in panoramic and standard intraoral radiography. Panoramic radiographs used alone were ineffective diagnostic aids in the detection of early interproximal carious lesions, particularly enamel lesions. The best radiographic survey in terms of numbers of enamel interproximal carious lesions detected was the combination of periapical plus posterior bitewing radiographs. For interproximal lesions extending through the enamel and into the dentin, all combinations except panoramic radiographs used alone showed comparable usefulness. For lesions involving the enamel and dentin, and extending half way or more from the dentinoenamel junction to the pulp, there generally were no significant differences between any of the combinations.


Considerations in dental treatment of children with ectodermal dysplasia. Characteristics of ectodermal dysplasia and agammaglobulinemia have been presented and a case in a 6 1/2-year-old boy having both genetic diseases is reported. The child had been mocked by his peers at school. A maxillary overlay denture and mandibular cast denture were constructed using a Baker bar and cast gold thimble crowns. The parents reported that the patients personality changed favorably after dental treatment was completed. He is now 13 years of age, has had his dentures replaced once, and enjous a rather active life with the aid of antibiotics and supplemental globulins.


Urinary infection in children in general practice: a laboratory view. Children with urinary infection present at first to their general practitioners; paediatricians to whom they may be referred must assess the validity of the bacteriological diagnosis made at that time. With this in mind an analysis has been made of the laboratory findings in 2204 mid-stream urine specimens from 1586 children between the ages of two and 12 years examined at the request of their general practitioners during the course of one year. The contamination rate was shown to be low; 8% of the specimens from boys and 19% of those from girls showed definite infection, and the ratio of infections in boys to girls was 1:4. There was a considerable difference in the infecting organisms in the sexes. Analysis of the reasons for sending the specimens revealed that a high percentage of children who complained of urinary symptoms did not have infection. Of the children complaining of enuresis only there was a significantly greater incidence of infection in girls than in boys. In the absence of any large studies of urinary infection in domiciliary practice, data from a laboratory which serves many practitioners can contribute to knowledge of the disease.


Epidemiological studies on the 1967-1968 foot-and-mouth disease epidemic: the reporting of suspected disease. From an analysis of the telephone reports in ten FMD Control Centres in the West Midlands, the veterinary officers' reports on each outbreak, the farm patrol reports and the daily number of outbreaks announced on the 17.50 h B.B.C. T.V. News, it would appear that the reporting of suspected outbreaks was indirectly related to the local disease activity. Private veterinary practitioners reported older cases of FMD at the beginning and end of the epidemic than in the middle.


Neonatal infection due to Salmonella worthington transmitted by a delivery-room suction apparatus. An outbreak of diarrhoea due to Salmonella worthington in five newborn babies, 5 weeks after a similar outbreak in 13 babies for which no cause had been found, occurred in the nursery of a maternity ward. The source of infection was traced to the contaminated rubber tubing of a mechanical suction apparatus. S. worthington was isolated from the rubber tubing and the Y connexion of the suction apparatus from which all the five infected babies had received suction. Reflux of contaminated amniotic fluid into the sterile catheter connected to the apparatus some time before use could have been the means of introducing the infected material to the oropharynx of the newborn babies, and amniotic fluid, acting as a good medium to support the growth of S. worthington, might be responsible for the long-lasting contamination.


The size of airborne dust particles precipitating bronchospasm in house dust sensitive children. We have assessed the effect of house-cleaning procedures on changes in airborne dust and bacteria counts and correlated these with respiratory function tests in 14 children with bronchial asthma who were known to have developed attacks at home, and who had positive skin tests to house dust and the house-dust mite. We have demonstrated that after cleaning procedures a positive and statistically significant correlation exists between the increase in the numbers of small particles, 2 mum. and less in diameter, in the environment, and reduction in mean peak flow. This indicates that particles of this size penetrate the bronchial tree and are the causative factor in the genesis of bronchospasm.


WRL 105 strain live attenuated influenza vaccine; comparison of one and two dose schedules. Haemagglutinating inhibiting antibody (HAI) responses were determined and clinical reactions recorded in 162 adult volunteers who received either 1 or 2 intranasal doses of 10(7-0) EID50 WRL 105 strain live influenza vaccine or placebo. After administration of a single dose of vaccine significant antibody responses were obtained in 69 (70%) of 98 volunteers with initial antibody titres of less than or equal to 1/20. Of the 70 volunteers who received a second dose of vaccine, 62 provided a further post-vaccination sample of serum, and only 3 (4-8%), who had not responded to the first dose of vaccine, produced a significant antibody response. Local, upper respiratory and constitutional symptoms were recorded more frequently after the administration of a first dose of vaccine than after placebo or a second dose of vaccine. The symptoms were of a minor nature except in one volunteer who, after the first dose of vaccine, developed influenzal symptoms followed by bronchitis.


Isolation of salmonellas from sewage-polluted river water using selenite F and Muller-Kauffmann tetrathionate. Selenite F broth and a modified Muller-Kauffmann tetrathionate broth were investigated using sewage-polluted natural water as inocula. The modification of the tetrathionate medium was necessary as commercial alternatives would not allow multiplication of small numbers of salmonellas. The wide range of molar concentrations in different tetrathionate broths was emphasized. Selenite F broth was more efficient than Muller-Kauffmann tetrathionate broth, in our hands, with the material tested. Direct inoculation of the enrichment media was used. Each of the two media examined had a bias towards selection of certain serotypes. If possible, both enrichment broths should be used to obtain maximum information.


Salmonella crossness--a new serotype containing a new comatic (O) antigen, 67. A new salmonella subgenus I serotype is described. Strein C.S. 1608/73, serotype 67:R:1, 2, was isolated from activated sewage sludge and was assigned the name S. crossness. The serotype is biochemically atypical in its ability to utilize sucrose and this ability appears to be controlled by a transferable plasmid.


Quality control of the isolation rate of pathogens in medical microbiology laboratories. Two statistical analyses are suggested to compare the success rates in isolating and identifying pathogenic organisms from specimens achieved by different laboratories participating in a quality control scheme. An example is given in which the analyses are applied to 25 laboratories that received 30 simulated specimens.


The treatment of soil infested with the human whipworm, Trichuris trichiura. The soil fumigants methyl bromide, chloropircrin and Basamid or mixtures of  Basamid and chloropicrin proved to be of no use in filling T. trichiura ova in soil. However, on untreated plots the eggs died at a rate such than only 20% of the ova remained viable after 18 months.


A comparison of influenza and respiratory syncytial virus infections among infants admitted to hospital with acute respiratory infections. Among 741 children under 5 years admitted to hospital with respiratory infections during two winters, infection with influenza A virus was diagnosed in 70 (9%), with influenza B virus in 8 (1%), and with respiratory syncytial virus (RSV) in 259 (35%). Both influenza virus and RSV infections were diagnosed most frequently in children under the age of one year, and diagnosed more frequently in males than females. Influenza illnesses were more severe in boys than girls. Both infections occurred more often, but were not more severe, in children from a conurbation than in those from 'rural' areas. Convulsions were the cause of 36% of admissions with influenza A infections, but were rare in RSV infections. Bronchiolitis was the reason for 39% of admissions with RSV infections, but was rare in influenza infections. It is suggested that infants admitted to hospital are a good source of influenza virus strains for monitoring antigenic variation.


The effect of cigarette smoking on susceptibility to epidemic influenza and on serological responses to live attenuated and killed subunit influenza vaccines. The effects of cigarette smoking on the incidence of epidemic influenza and on the serological response to influenza vaccination with killed subunit and live attenuated vaccines have been investigated during comparative vaccine trials in Western Australia. It was found that cigarette smokers with no pre-epidemic haemagglutination-inhibiting (HI) antibody (titres of less than or equal to 12) were significantly more susceptible to epidemic influenza than non-smokers. Smokers were no more susceptible however, if they had possessed detectable pre-epidemic HI antibody. A significantly higher proportion of smokers sero-converted after receiving the live virus vaccine than their non-smoking counterparts, but this could not be correlated with pre-vaccination HI antibody titres. The longevity of the immune response to the subunit vaccine was severely depressed 50 weeks post-vaccination in smokers who had possessed little or no immunity before vaccination (titres of less than or equal to 12). This antiboyd deficit was not observed in live virus vaccines or subunit vaccinees with pre-vaccination HI antibody (titres of greater than or equal to 24). Post-vaccinal symptoms were similar regardless of vaccine group or smoking history.


Laboratory evaluation of WBA 8119 as a rodenticide for use against warfarin-resistant and non-resistant rats and mice. Feeding tests were carried out in the laboratory to evaluate WBA 8119 as a potential new rodenticide against wild common rats (Rattus norvegicus), ship rats (R. rattus) and house mice (Mus musculus). The results obtained are compared with data previously obtained for difenacoum, another member of the same series of 4-hydroxycoumarin anticoagulants. With warfarin-resistnat and non-resistant common rats, complete kills were obtained using a concentration of 0-0005% for 2 days, or 0-001% for 1 day: a 1-day test at 0-0005% killed 6 out of 10 and 17 out of 20 of the two types respectively. At 0-0005% complete kills of resistant ship rats were obtained after 2 days exposure and of resistant house mice after 1 day, but at 0-002% for 2 days there was some survival. Non-resistant ship rats and house mice were all killed after 2 days feeding on 0-002% bait. In 2-day palatability tests, R. norvegicus showed no significant aversion to the poison at 0-002% and 100% mortality was obtained. The poison was significantly unpalatable to R. rattus at 0-005% and to M. musculus at 0-005% and 0-002%, although with the last species these concentrations gave complete kills. It is concluded that WBA 8119 has greater activity than other known anticoagulants against the three commensal species examined. The laboratory results suggest that concentrations between 0-0005% and 0-002% would be suitable for field use against common rats, and between 0-002% and 0-005% for ship rats and house mice.


Trials of the anticoagulant rodenticide WBA 8119 against confined colonies of warfarin-resistant house mice (Mus musculus L.). The efficacy of the newly developed anticoagulant rodenticide WBA 8119 was evaluated against the house mouse (Mus musculus L.) using individual and family groups of warfarin-resistant animals. WBA 8119 at 0-002%, 0-005% and 0-01% in pinhead oatmeal bait gave complete kills of mice in 'no-choice' feeding tests carried out in cages and small pens. In replicated 21-day treatments on families of mice confined in larger pens conditioned to feeding on plain foods, the overall mortalities obtained using the three formulated poison baits were 71/72, 62/63 and 57/57 respectively. The results of the WBA 8119 toxicity tests are considered in relation to previous findings on other anticoagulant rodenticides, particularly difenacoum. In equivalents tests, WBA 8119 performed better than difenacoum. The data thus suport the laboratory findings that WBA 8119 is the most active anticoagulant so far tested for the control of warfarin-resistant house mice.


Trials of the anticoagulants rodenticide WBA 8119 against confined colonies of warfarin-resistant house mice (Mus musculus L.). The efficacy of the newly developed anticoagulant rodenticide WBA 8119 was evaluated against the house mouse (Mus musculus L.) using individual and family groups of warfarin-resistant animals. WBA 8119 at 0-002%, 0-005% and 0-01% in pinhead oatmeal bait gave complete kills of mice in 'no-choice' feeding tests carried out in cages and small pens. In replicated 21-day treatments on families of mice confined in larger pens and conditioned to feeding on plain foods, the overall mortalities obtained using the three formulated poison baits were 71/72, 62/63 and 57/57 respectively. The results of the WBA 8119 toxicity tests are considered in relation to previous findings on other anticoagulant rodenticides, particularly difenacoum. In equivalent tests, WBA 8119 performed better than difenacoum. The data thus support the laboratory findings that WBA 8119 is the most active anticoagulant so far tested for the control of warfarin-resistant house mice.


[Studies on high temperature oxidation of noble metal alloys for dental use (I). Formation of oxide layers and oxidation rate (author's transl)]. Eight commercial and two experimental alloys were examined. The cast specimens were polished metallographically and oxidized at 700 degrees and 800 degrees C in air. An electron probe X-ray microanalyser and a microthermobalance were employed to investigate the oxidation behavior of the alloys. The results obtained were as follows: 1. The copper in the alloys was selectively oxidized and the scales formed on the alloys consisted of two layers, CuO overlying Cu2O. 2. The oxide particles in the internal oxidation zone (subscale) on the alloys containing only Cu as the base metal were Cu2O and on the alloys containing Zn, Cd, and Ni with Cu were ZnO, CdO, and NiO, respectively. 3. The size of the ZnO and CdO particles in the subscale increased with the penetration into the specimen. 4. The ZnO particles in the metal-subscale interface showed preferential precipitation at the grain boundaries. 5. When the oxide particles in the subscale did not develop remarkably, the oxidation rate at constant temperature conformed with the parabolic law. 6. In the 18 carat gold alloy, the oxidation rate at 800 degrees C was about 10 times that at 700 degrees C. 7. Owing to preferential oxidation of the Cu in the alloys, Cu concentration in the outer layer of the metal decreased remarkably and Au, Pt, Ag and Pd concentration increased.


[Studies on high temperature oxidation of noble metal alloys for dental use. (II) Effects of high temperature oxidation on casting (author's transl)]. The specimens which were cast from commercial alloys were polished metallographically and then oxidized at 800 degrees C for 1 hour in air. The results obtained were as follows: 1. The reduction rate of Cu aginast the original Cu amount in the alloy is given by the following equation: (see article) where S is surface area of the casting, KW is oxidation rate constant, t is time, Wc is weight of the casting, Ccu is weight percent of Cu, and n is between 1 and 2. 2. Owing to decrease of the Cu concentration in the outer layer of the alloy, the age-hardening did not appear in that layer. 3. Reflexibility of the polished surface of alloys became lower than that of the matrix due to precipitation of the oxide particles. 4. Hardness numbers of the internal oxidation zone (oxide particles, ZnO) decreased to 1/2 of the matrix. 5. The surface roughness of specimens after pickling was affected by the shape of oxide particles in the internal oxidation zone and varied with the different commercial alloys. 6. The dimensional change of casting due to oxidation is given by the following equation: (see article) where sigmacu is density of copper, KW is oxidation rate constant, t is time and n is between 1 and 2.


[Studies on high temperature oxidation of noble metal alloys for dental use. (III) On high temperature oxidation resistance of noble metal alloys by adding small amounts of alloying elements. (author's transl)]. The previous report pointed out the undesirable effects of high temperature oxidation on the casting. The influence of small separate additions of Zn, Mg, Si, Be and Al on the high temperature oxidation of the noble metal alloys was examined. These alloying elements were chosen because their oxide have a high electrical resistivity and they have much higher affinity for oxygen than Cu. The casting were oxidized at 700 degrees C for 1 hour in air. The results obtained were as follows: 1. The Cu oxides are not observed on the as-cast surface of noble metal alloys containing small amounts of Zn, Mg, Si, Be, and Al. The castings have gold- or silver-colored surface. 2. After heating of the unpolished and polished castings, the additions of Si, Be and Al are effective in preventing oxidation of Cu in the 18 carats gold alloys. Especially the golden surface is obtained by adding Be and Al. But there is no oxidation-resistance on the polished castings in the alloys containing Zn and Mg. 3. The zinc oxide film formed on the as-cast specimen is effective in preventing of oxidation Cu in 18 carats gold alloys. 4. It seems that the addition of Al is most available in dental application.


[Studies on the strength and the cutting performance of dental canal reamer. (III) Cutting performance and torsional fracture (author's transl)]. Characteristics of cutting torque and fracture strength of pulp canal reamers are important problems as for the severity used at many of dental cutting tools. And it is the most difficult problems that reamers are cutting tools to be used for magnification of root canals. So, this paper makes a report on the measurements of reamer's section and dimension of the under hole, which are required for cutting test, and on the safety of characteristics of dental canal reamers. Diameter of under hole are determined by the relationship of reamer's section. And these results of measurements are compared with the Japanese Industrial Standard values and we discussed the probabilities of the clearance of these dimensions. Cutting torque of reamers are measured with twisting test machine of our making. Concerning the safety of fractures, we apply the theoretical analysis for the fracture to torque of bite tips and estimated the fracture torque of cutting section of reamers. And probablity of twisting fracture of reamers are existed about from one half to one-fifth values for the dental reamers of practical used.


[Age-hardening of minor amounts of iron added Au-10% Pt alloy (Part II) (author's transl)]. The aging process has been studied by 0.09, 0.28 and 0.48 wt% iron added gold-10 wt% platinum alloys. The results obtained are as follows: (1) From the isochronal and isothermal aging, the electrical resistances decreased in proportion to increasing of iron. These decreases are occured to be ordered of iron and platinum. (2) The electrical resistances in the isochronal aging curves are minimized at limited temperature of 600 degrees approximately 680 degrees C, and the growth of nodules would be saturated at this temperature. (3) The apparent activation energies of aging process of Au-Pt-Fe alloys (0.09, 0.28 and 0.48 wt% Fe) were in the range of about 37 approximately 44 Kcal/mole. (4) In the results of the images atructure of nodules was lamella of fcc FePt3 phase and Au-Pt solid solution phase.


Studies on the relationship between FSH and germ cells: evidence for selective suppression of FSH by testicular extracts. The evidence supporting the relationship between the seminiferous epithelium and circulating FSH levels has been reviewed and provides support for the concept that the testis produces a factor capable of specifically controlling FSH concentrations. Detailed quantitative histological studies of the seminiferous epithelium have demonstrated a highly significant inverse relationship between the number of spermatogonia per tubule cross-section and serum FSH levels in men with testicular disorders.


Secretion and role of androgen-binding proteins in the testis and epididymis. The Sertoli cell appears to be a target cell for both FSH and androgen. FSH stimulates the Sertoli cell to produce an androgen-binding protein (ABP) which may serve to increase the accumulation of androgen in the seminiferous tubular epithelium and make it available for binding by intracellular androgen receptors. This might be one way by which FSH enhances the action of androgen on spermatogenesis. Androgen acts on the Sertoli cell to increase its response to FSH resulting in increased production of ABP and of other substances which exert trophic effects on spermatogenesis.


Retreat from death?

Retreat from death? The case of Terry Jenkins, a 15-year-old boy, who was found to have a sarcoma of bone, was discussed on television under the title of 'Inside Medicine'. The discussion revolved, not so much on the clinical details of the case or even of cancer of bone in a young person, as on the emotional disturbance that followed when the boy's mother refused to allow her son to be told about the nature of his illness or the proposed treatment. With hindsight, as is made clear in the discussion, the case should have been handled quite differently, with the general practitioner acting as the lynch pin and a psychiatrist and a social worker being brought into the emotional 'treatment' of the boy and his mother. As it was the boy was so disturbed about what he had guessed about his condition that he attempted suicide: fortunately he was rescued in time, and Terry is now stable, working, and mobile on his artificial leg.


In vitro studies on the enhancement of Rauscher virus-induced erythroblastosis by complete Freund's adjuvant in BALB/c mice. Inoculation of complete Freund's adjuvant (CFA) into BALB/c mice either before or after infection with Rauscher murine leukemia virus (MuLV-R) led to an acceleration of the disease as determined by spleen weight. Treatment with CFA also induced a higher number of spleen erythroblast foci and, in the bone marrow, erythropoietin-independent cells that produced erythroid colonies in vitro. CFA induced in the bone marrow not only an increase in myeloid progenitor cells that can produce colonies in agar, but an ever larger increase in the number of erythroid colony-forming cells. Virus-induced erythroblastosis was probably enhanced by CFA due to the production of many target cells. The more primitive burst-forming cell, which produced large colonies of erythroid cells after 10 days in culture, was also physiologically transformed in MuLV-R-infected mice; bursts could be formed by cells of such animals in the absence of erythropoietin.


Monitoring of murine osteosarcoma by serial alkaline phosphatase determinations. To establish that alkaline phosphatase (AP) was released by osteosarcoma cells, we measured this enzyme in C3H/HeJ mice with im-implanted osteosarcoma and in in vitro cultures of neoplastic cells subjected to short-term incubation. We found that 10(5) osteosarcoma cells synthesized a significant amount of AP in vitro in 30 minutes at 37 degrees C. A good correlation existed between pulmonary metastatic tumors and the AP values. Serum AP measurements indicated approximate sizes of disseminated and localized tumors, but could not monitor early localized tumors.


Friend spleen focus-forming virus production in vitro by a nonerythroid cell line. We developed a cell line (IS) that continuously produced both Friend spleen focus-forming virus (SFFV) and XC plaque-forming virus in vitro. The line was derived from the enlarged spleen of an inbred SIM mouse previously infected with a polycythemic strain of Friend leukemia virus in vivo. Friend SFFV titers of 10(4) spleen focus-forming units/ml of culture medium were maintained for more than 200 cell generations. The virus from IS cells induced the splenomegaly and high hematocrit typical of Friend virus-induced erythroid disease in SIM mice. Cells of the IS line were adherent and phagocytic and had a low saturation density. They produced no tumors after being injected sc into normal syngeneic hosts and no spleen colonies after being injected iv into supralethally irradiated hosts. IS cells did not have the character of erythroid cells: They did not contain detectable heme as measured by benzidine-peroxide reagent, did not contain globin mRNA in detectable amounts, and did not produce erythroid colonies in plasma culture in the absence or presence of erythropoietin. According to these criteria, growth in the presence of dimethyl sulfoxide did not stimulate erythroid differentiation of IS cells. We concluded that Friend SFFV can infect nonerythroid spleen cells but that replication of the virus was not obligatorily coupled to expression of genes associated with the erythroid phenotype.


Ssytemic effects of intravenous polyriboinosinic-polyribocytidylic acid in man. To investigate the systemic, clinical and laboratory effects of iv polyriboinosinic-polyribocytidylic acid (poly I-poly C), 32 doses of poly I-poly C were administered to 22 patients. Doses between 1 and 10 mg/kg induced the formation of serum interferon (IF) and fever. Whereas a direct relationship was seen between the poly I-poly C dose and fever, serum IF levels were not significantly changed by increasing the dose of poly I-poly C over a log range from 1 to 10 mg/kg. Transient abnormalities were noted in liver function tests in 4 of 13 patients who received greater than 6.0 mg/kg. Other laboratory changes were confined to an increase in the absolute granulocyte count that paralleled fever development and abnormalities in coagulation parameters of 1 patient. In vitro lymphocyte DNA synthesis in response to mitogens was transiently impaired at times corresponding to serum IF appearance. These studies have established dose levels of poly I-poly C that can be safely administered to man with minimal toxicity and result in IF induction.


Occurrence of spontaneous tumors in the germfree F344 rat. The incidence of spontaneously occurring neoplasms was observed over 10 years in a colony of germfree F344 rats (78 males and 102 females) representing 10 generations of inbredding. Leukemia was the most common neoplasm (25.6% of males, 36% of females) followed by mammary tumors (11.5% of males, 19.6% of females). Various other tumors developed in 9% of the males and 5% of the females. The overall incidence of spontaneous tumors was comparable to that reported for conventional rats of different strains. This was particularly true of leukemia for which the most data were available. However, for unknown reasons, significantly fewer solid tumors were observed in germfree than in conventional male rats.


Immunocompetence and prognosis in children with acute lymphoblastic leukemia: combination of two different maintenance therapies. Intensive chemotherapy in patients with leukemia produced immunosuppression. The level of immunocompetence correlates with prognosis. The immunological function of 29 children with acute lymphoblastic leukemia (ALL) in complete remission and on 2 different maintenance therapies was evaluated and compared with 16 normal children (Group A). Sixteen children (Group B) with ALL received 6 mercaptopurine (6MP) daily and methotrexate (MTX) twice a week, and 13 children (Group C) received 6MP and MTX weekly for maintenance. There was depression of both cellular immunity, measured by the number of T cells and skin tests, and humoral immunity, measured by number of B cells, primary antibody production to typhoid vaccine, and levels of immunoglobulins. However, continuous maintenance therapy (Group B) produced significantly more severe immunosuppression of cellular immunity than the intermittent therapy (Group C). Humoral immunity was equally depressed in both groups of leukemia patients, but was less altered than cellular immunity. Concomitantly, patients with intermittent maintenance chemotherapy had less hematologic depression, fewer episodes of infection, and fewer died in complete remission. Patients of both groups with higher levels of immunocompetence had better prognosis with longer duration of complete remission than patients with severe immunosuppression. Out of 6 patients with "favorable immunocompetence" only 1 relapsed at 7 months and the other 5 remain in complete remission from 8 to 31 months. Among 23 leukemic patients with "unfavorable immunocompetence," 15 relapsed and 8 remain in complete remission from 9 to 26 months.


Emphysematous gastritis in a leukemic child. Emphysematous gastritis associated with gram-negative sepsis is described in a leukemic child on chemotherapy and steroids. Bubbly-appearing air and thickening of the gastric wall were radiographically demonstrated. This is analogous to the demonstration of air within the thickened bowel wall in necrotizing enterocolitis, which is not unusual in seriously ill leukemic children. Gastric involvement has not been previously reported.


[First aid to patients with multiple facial injuries]. The first aid techniques available for treating patients with multiple face traumas are reviewed: first aid proper (mouth-to-mouth respiration, mouth-to-nose respiration and external heart massage); picking up the patient (radio-TV link between ambulance and Resuscitation Department); transport (rationally planned ambulance with expert in resuscitation aboard); reception area (with radio-TV link, the Resuscitation physicianc can alert staff in the ward to which the patient should be admitted).


[Local-regional dental anesthesia without vasoconstrictors]. Since Braun in 1905 first associated adrenalin with Einhorn's novocaine (procaine) to augment anaesthetic action, many attempts have been made to replace this vasoconstrictor because of the often severe inconveniences it can cause (cardiovasculopathic, arteriosclerotic, etc.). Reduction in dosimetry is recalled in brief: 1-corbasil; vasopressin; nor-adrenalin. It is personally considered that none of these measures ever successfully replaced adrenalin, nor did they prove to be so harmless as was originally believed. Finally, the refinement of biochemical research enabled more powerful and less toxic locoregional anaesthetics to be marketed and these provided ideal anaesthesia without vasoconstrictors. Pure carbocaine has been personally used exclusively for more than four years, with the two-fold advantage of practically completely avoiding any general inconvenience, particularly in cardionephrotics, diabetics, etc. and, in plexic (or terminal) injections, avoiding the threat of ischaemia which is the most frequent cause of alveolitis and of secondary haemorrhage. This locoregional anaesthetic without vasoconstrictor is therefore recommended, while the vast majority of clinics continue to use anaesthetics associated wtih non-indispensable and dangerous vasoconstrictors.


[Diftalone in the prevention and therapy of inflammatory complications of dental surgery]. The capacity of diphthalone to prevent  postoperative inflammation was evaluated in 46 patients who had undergone dental surgery. The drug was always administered at a dose of 1000 mg/die for 5-7 days using two different therapeutic schedules, the before and after the operation in 23 patients and only afterwards in the other half. Results were satisfactory although the most evident benefits were obtained with the first schedule, namely when treatment was commenced two days prior to operation. Tolerance was good.


[Clinical considerations on the use of CI 585 (ketalar) in pediatric odonto-stomatology]. Three years' experience with ketamin in paediatric odontostomatology is reported. A comparison is made between the disadvantages and advantages of this anaesthetic by comparison with fluothane.


Partial denaturation mapping of cloned histone DNA from the sea urchin Psammechinus miliaris. A cloned 5.6-kb DNA repeat unit of Psammechinus miliaris containing all five histone coding sequences of known order and polarity has been shown to fall clearly into a low melting and a high melting half by thermal denaturation. The topoligies of the DNA sequences thus defined were determined by partial denaturation mapping in the electron microscope to gain further insight into the distribution of spacers and genes within histone DNA.


[Controlled gradual lengthening of the mandible after osteotomy]. The procedures used to correct large discrepancies in the length of the mandibular body are described and experimental results are reported. The technique is realized using an orthodontic applicance that permits the progressive lengthening, after osteotomy of the mandibular body and also retains the approximation of the resected mandibular segments. Two dogs were used for the experimentation, achieving mandibular body lengthening of 5 and 15 millimeters. The bone neoformation was studied hystologically by means of microradiography and tetracyclines induced fluorescence. The surgical technique was carried out without damage to the mandibular nerve. The hystological examination shows no conspicous alteration of the nerve fibres.


[A familial strain of amelogenesis imperfecta hypoplastic type with dominant x-linked heredity]. Hypoplastic amelogenesis imperfecta in members of four generations of a Campanian family is described. The females were  affected to a lesser degree. A dominant X-linked mutation was apparently involved. The different forms of amelogenesis imperfecta are described in the light of their anatomical, clinical and radiological pictures and their transmission modalities. Suitable corrective treatment is required to offset the damage to masticatory function, and associated psychological and emotional consequences, especially in female subjects.


Unusual encephalitic illnesses in a child with acute leukaemia in remission: possible role of measles virus and Toxoplasma gondii. We report a girl who developed an encephalitic illness with visual loss after two years treatment for acute lymphoblastic leukaemia. The visual loss was found to be due to bilateral macular degeneration. She later developed radiological evidence of intracranial calcification and temporal lobe epilepsy. A second episode of encephalitis occurred when she had been off all antileukaemic treatment for three years and this left her with a right hemiparesis. Investigation suggested involvement with both measles virus and Toxoplasma gondii as a cause for these illnesses.


Digoxin poisoning: case report.

Digoxin poisoning: case report. Digoxin overdose leading to toxicity causes a variety of symptoms ranging from cardiovascular, gastrointestinal and central nervous system effects. Toxicity occurs at a serum level of 3.0ng/ml. The value of phenytoin sodium in treatment of digoxin toxicity is discussed.


Treatment success in alcoholism.

Treatment success in alcoholism. Two hundred and sixty-two male and 51 female alcoholics treated in 1971 were followed up for two years: 71 percent of the sample were contacted: 43.5 percent males were abstinent or improved: 56.7 percent of the females were abstinent or improved. Treatment success was co-related with being married, being in the upper socio-economic groupings, and staying for the full 12 week inpatient course. Repeated failure in treatment was associated with being single, of low socio-economic status, and with one previous admission for alcoholism. It is suggested that the main factor in the increasing prevalence of alcohol problems in the general population is the relative cheapness of liquor.


Gastric bypass for morbid obesity.

Gastric bypass for morbid obesity. Failure of conservative methods of control of gross obesity has led to the adoption of surgical measures. The operation of intestinal bypass, may be associated with the number of unpleasant complications. As a result there has been recent interest in the operation of gastric bypass involving an 80 to 90 percent gastric exclusion procedure. We report on the results of our first 19 patients undergoing this operation, a six to 15 month follow-up. The early results would suggest that gastric bypass in the treatment of morbid obesity is likely to prove superior to the various forms of intestinal bypass.


Objective respiratory screening among Dunedin public servants. The results of a questionnaire concerning respiratory symptoms in Dunedin public servants have been reported earlier (de Hamel, O'Donnell, 1972). This report is of the results of spirometry in the same population. Fifty-five percent of 1079 men and 59 percent of the 310 women with normal mass miniature chest x-rays showed an FEV 1.0 below the predicted value, but in only 9 percent of each sex was the FEV 1.0 less than 80 percent of predicted. Bronchitic symptoms and a history of regular cigarette smoking were associated with an impaired FEV 1.0. The FEV 1.0 was normal in many giving a history of the bronchitic symptoms cough, phelgm or wheezing. The FEV 1.0 of overweight men was not significantly different from the other men. Attention is drawn to the high frequency of chronic bronchitis in the population and the correlation of this with moderate and heavy cigarette smoking. The questionnaire disclosed more abnormality within the population than did the spirometrey. They may complement one another when effort is being directed at health education.


The need to train anaesthetists in New Zealand. A survey of New Zealand public hospitals undertaken at the end of 1974 shows that the country is training half the number of anaesthetists to maintain the public hospital-based anaesthetic services. There is a need to develop and expand training programmes for anaesthetists. New graduates can be assured that there are career prospects in the specialty.


Comparison of a slow release formulation of oxprenolol with conventional oxprenolol in the treatment of hypertension. Patients with moderate to severe hypertension were studied during a 12-week period, during which they were given a slow release formulation of oxprenolol once daily, in a dosage equal to their previous total daily dose of oxprenolol given in divided doses. There were no systematic differences between blood pressures at the beginning and end of the 12-week period. The once-daily dosage was well tolerated and was preferred by the patients. This regime offers advantages in terms of patient compliance with lifelong therapy in what is usually a symptomless condition.


An assessment of the need for vaccination amongst junior medical staff. This study was set up to determine the susceptibility of junior medical staff to communicable infectious diseases. Thirteen female and 39 male staff were investigated. Antibodies to morbilli, varicella zoster, toxoplasma, cytomegalovirus, hepatitis B, mumps and rubella were determined. Hepatitis B surface antigen tests were also carried out. Twelve males were susceptible to mumps and 10 were subsequently vaccinated. No side effects were noted. Three of five females susceptible to rubella requested vaccination and all showed an antibody response without early or delayed side effects. The desirability of offering vaccinations to susceptible adult staff is discussed.


Are 24-hour urine collections necessary for the measurement of steroid excretion rates? In the assessment of ovarian activity, testicular response in human chorionic gonadotrophin (HCG), and placental and fetal viability during pregnancy, measurements made on small samples of urine may be used to monitor changes in 24h steroid output; the collection of 24h urine specimens is not necessary. For women, 24h output approximately 10 R (R, steroid/creatinine in small urine samples; concentrations expressed in SI units of amount). For men, 24h output approximately 14 R.


Deep vein thrombosis after femoropopliteal bypass grafting with observations on the incidence of complications following the use of dextran 70. Radiological thrombosis was demonstrated on six occasions in the leg veins in 66 patients following the placement of 71 femoropopliteal bypass grafts. All patients received dextran 70 as prophylaxis postoperatively. The incidence was similar for grafts with the lower anastomosis either above or below the knee joint. No predisposing factors to venous thrombosis were apparent other than blood dyscrasias. A further group of patients who had arterial reconstructive procedures were examined to determine the incidence of the complications of bleeding and heart failure which might be attributed to the routine use of dextran 70. The incidence of complications in this larger group indicates that the routine use of dextran 70 is not a significant factor in their occurrence in the postoperative period.


Re-instatement of regular defecation routines in a four-year-old boy. A four-and-a-half year old boy was withholding faeces for up to eight days. A programme of positive reinforcement contingent upon his being placed on the toilet according to a schedule was introduced. An operant technique of immediate, positive reinforcement was utilised to reward bowel movements. Results indicate that the reinstatement of a two-daily routine of defection was achieved after 48 days. The programme was introduced and maintained by the child's mother with no outside intervention in the routine.


The reduction of soiling behaviour in an 11-year-old boy with the parent as therapist. An 11-year-old boy who had soiled daily for six years since entering school had threatened to commit suicide. Following an initial assessment, a parent was trained to monitor an experimental procedure that effectively reduced soiling to a level where the only occurrence noted in two months resulted from a bout of diarrhoea.


Medical students design their ideal medical school. New Zealand medical students were asked to design the ideal medical school. The areas they marked for change included candidate selection, curriculum, teaching standards and methods of assessment. They suggested ways of making medical training a more personal, broader and better integrated experience. The rigid division between pre-clinical and clinical studies was criticised as were time-wasting lectures and rapid-fire lecturers. The students' recommendations were similar to many which have appeared in the literature of medical education.


Lead poisoning caused by glazed pottery: case report. A case of severe lead poisoning is described. This was caused by the ingestion of fruit drink prepared and stored in lead-glazed jugs. Results of tests to measure the extractability of lead from the jugs are given.


Thoracic and arterial pressures, blood flow and syncope. The relationship between elevation of the thoracic pressure and the thoracic volume and blood pressure was investigated in man. Raising the thoracic pressure produced an increasing hypotension and ultimately fainting. Cine-radiography showed a reduction in heart size while the high thoracic pressure was maintained.


Thermoregulation during mild exercise.

Thermoregulation during mild exercise. A comparison was made of the thermoregulatory effects of wearing black or white clothing during exercise under radiant heating. For subjects in black clothing the skin temperature was higher than with white but the rectal temperature and heart rate were lower.


Blood volume and exercise in dogs.

Blood volume and exercise in dogs. The plasma volume and haematocrit ratio were examined in dogs during exercise. The plasma volume increased after exercise and persisted for 10 minutes on its cessation. There was a 14 percent increase in the haematocrit ratio.


Osteopathy due to methotrexate.

Osteopathy due to methotrexate. Two children with ALL receiving long-term therapy with methotrexate (50 mg/week i.v.) developed severe osteoporosis accompanied by swelling of the joints, gait disturbances and fractures after minimal trauma. Bone scans 85Sr disclosed a decreased input and increased turnover of calcium especially in the most used bones. The data of the calcium phosphorus metabolism are within the normal range. The minimal changes in the biopsy material of the iliac crest may be due to little mechanical use so that this part of the skeleton is not much affected by the osteoporosis. Since the controls receiving the same therapy did not have signs of such severe osteoporosis it is assumed that an additional, till unknown factor may play an additional role in this kind of methotrexate side effect.


Prediction of relapse and remission in AML by marrow culture criteria. Bone marrow culture studies in semi-solid agar have been performed on 250 patients presenting with acute myeloid leukemia. The detection of a spectrum of qualitative defects in the proliferation, differentiation and biophysical characteristics of leukemic colony forming cells (CFU-c) has permitted a detailed analysis of the relapse-remission status based on transition from qualitatively abnormal cell growth in vitro to a normal pattern of proliferation and differentiation. Changes in vitro generally preceded clinical or morphological evidence of the onset of relapse or remission and serve as a valuable additional parameter in monitoring clinical status. Marked cyclic changes in CFU-c incidence appeared to characterize the remission phase of AML and were frequently associated with fluctuations in marrow blast cell count which can lead to mis-diagnosis of incipient relapse. Detection of qualitative defect in marrow culture serves to distinguish patients with preleukemic disorders at high risk of termination in acute myeloid leukemia from patients with clinically similar disease who have not undergone further progression over a 2-4 year period of observation.


Significance of PHA induced clonogenic cells in chronic myeloid leukemia and early acute myeloid leukemia. A technique for cloning myeloblastic leukemic cells in semi-solid agar, after prior PHA stimulation, was studied in all phases of chronic myeloid leukemia. Phytohemagglutinin responsive cells were found in blast crisis and accelerated phase. In a small number of patients in the benign phase of their disease, colony growth with PHA was detected. A group of patients with early acute leukemia was also examined by this technique. The incidence of PHA colonies appeared to correlate with the progression of the disease. The potential application of this assay for early detection of leukemic clones and possible prediction of the rapidity of progression of the leukemic process is discussed.


Comparative electron-microscopic study of the erythrocytic line in refractory anemia (preleukemia) and myelomonocytic leukemia. The bone marrow erythrocytic precursors of 12 patients with refractory anemia (preleukemia) or myelomonocytic leukemia were studied by transmission electron microscopy. The results were tabulated in a semiquantitative manner and a comparison was established between the two main diagnostic groups. The following results are reported. 1. Similar nuclear and cytoplasmic abnormalities of the normoblasts were observed in preleukemia and leukemia. 2. A nuclear lesion consisting of nuclear clefts and blebs was demonstrated in at least some of the normoblasts in all of the patients. Although not specific, this finding appears to be a new contribution in the field of preleukemia and myelomonocytic leukemia. 3. Iron overload, including the presence of pathologic sideroblasts, is common to both preleukemia and leukemia.


Acute myeloblastic leukemia after immunodepressive therapy for primary nonmalignant disease. Three patients treated with immunodepressive chemotherapy over a period of 43, 60, 38 months respectively, for primary nonmalignant disease, developed AML after cessation of chemotherapy. During the months preceding the AML outbreak, there were hematologic changes with seemed to reveal a preleukemic state. Our 3 patients, and 8 previously published cases, making a total of 11 patients, developed AML after chemical immunodepression for reasons which were neither hematologic nor neoplastic.


Preleukemia: does it exist?

Preleukemia: does it exist? In acute myeloid leukemia (AML), many of the remaining normal-appearing cells exhibit various abnormalities. An interpretation is that these cells are descendants of leukemic cells which have succeeded in overcoming the major final differentiation block that exists in AML. Direct evidence is quoted that red cell precursors in AML are of leukemic descent and it is claimed that the target cell of AML is the pluripotent stem cell. Next, evidence has been compiled that all three cell lines (red cell, n. granulocytes, platelets) exhibit qualitative defects in "prelukemia." Hence it is postulated that preleukemia per se doses not exist but that preleukemic states which with a rather high frequency sooner or later end in overt AML are actually true leukemias that, however, differentiate reasonably well. Another way of phrasing it is that preleukemic states are AMLs that present in partial and sometimes long-lasting remission, which only after months to years lose their differentiation ability and then are classified as AML.


Theoretical studies of the conformational properties of ribavirin. One of the factors required for the antiviral activity of the synthetic nucleoside, ribavirin (1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide), is the ability of the molecule to adopt the substrate conformation specified by the enzyme for which it is a competitive inhibitor, inosine 5'-phosphate dehydrogenase (IMP:NAD+ oxidoreductase, EC 1.2.1.14). The calculated glycosidic minimum for ribavirin is the high syn conformation, which is in agreement with experimental determinations of the molecule's solution conformation. The similarity in solution between the conformation of the active ribavirin molecule and the conformation of its inactive 5-methyl and 5-chloro derivatives indicate that some other substrate conformation is specified by the enzyme. The high anti conformation, found by these calculations to be close in energy to the high syn minimum, is postulated to be the active conformation required by the enzyme. The inactivity of the 5-methyl and 5-chloro derivatives is attributed to the much greater stability of these derivatives in the inactive high syn conformation.


Prediction of three-dimensional structures of enzyme-substrate and enzyme-inhibitor complexes of lysozyme. Conformational energy calculations were used to predict the three-dimensional structures of enzyme-substrate and enzyme-inhibitor complexes of lysozyme. A global search method, involving the use of a disaccharide fragment molecule, was used initially to determine all favorable binding regions at the active site. It is shown that the binding of a series of (nonfragmented) oligomers of N-acetylglucosamine is highly specific. The results show further that (a) the enzyme recognizes only one backbone conformation of the oligomer, corresponding to a left-handed helix, and (b) for saccharides containing two or more N-acetylglucosamine residues, two residues bind preferentially to the C and D sites. The calculations also suggest that the chair form of N-acetylglucosamine can bind to the D region. The saccharide residues of tetra-N-acetylglucosamine bind to the A-B-C-D sites, with the residues at the A-B-C sites having essentially the same conformation and orientation as those in the x-ray structure of tetra-N-acetylglucosamine-delta-lactone bound to lysozyme.


Modeling the resonance Raman spectrum of a metarhodopsin: implications for the color of visual pigments. Resonance Raman spectra of an invertebrate rhodopsin are reported. The spectrum of squid acid metarhodopsin is compared with the spectra of model compounds of the retinylidene chromophore in the all-trans conformation. Correlations made between acid metarhodopsin and these crystalline model compounds with known x-ray structures indicate that the chromophore in this intermediate is an all-trans protonated Schiff base. The data suggest a mechanism for the red shift in rhodopsin.


Free acid, anion, alkali, and alkaline earth complexes of lasalocid a (X537A) in methanol: structural and kinetic studies at the monomer level. We report below on nuclear magnetic resonance investigations of the structure and exchange kinetics for the free acid, anion, sodium complex, and barium complex of the ionophore lasalocid A (X537A) in methanol solution. A comparison between the proton and carbon longitudinal relaxation times of lasalocid in nonpolar and polar solvents demonstrates that the free acid (HX) is a monomer in methanol solution. Parallel proton and carbon relaxation measurements demonstrate that the anion (X-), sodium complex (NaX), and barium complex (BaX+) are also monomeric in methanol solution. These results are in contrast to the Na2X2 dimer and the BaX2-H20 dimer observed in crystals and in nonpolar (cyclohexane and methylene chloride) solutions. Large downfield shifts on complex formation (X- to NaX and BaX+) are detected for protons located on the polar face of the ionophore with their C-H bonds directed towards and proximal to the metal ion. The exchange of lasalocid anion between free (X-) and complexed (BaX+) states in methanol can be monitored from the temperature-dependent line shapes of the proton resonances at superconducting fields. The exchange rates are independent of the reactant concentrations and are characteristic of a rate-determining dissociation of BaX+ in methanol solution with activation parameters delta H++ = 6.5 kcal mol-1 (25 degrees) and delta S++ = -20.0 cal mol-1 degree -1 (1 cal = 4.184 J). The rate constants for dissociation and formation of BaX+ complex in methanol, 25 degrees, are 5.2 X 10(3) sec-1 and 1.5 X 10(10) M-1 sec-1, respectively. These studies were extended to derive the activation parameters for the exchange of lasalocid anion between BaX+ and NaX and between BaX+ and HX in methanol, while the exchange among HX, X-, and NaX is too rapid to be monitored on the time scale of nuclear magnetic resonance.


Structural characterization of a bridged 99Tc-Sn-dimethylglyoxime complex: implications for the chemistry of 99mTc-radiopharmaceuticals prepared by the Sn (II) reduction of pertechnetate. Reduction of pertechnetate by tin(II) in the presence of dimethylglyoxime is shown, by single crystal x-ray analysis, to yield a technetium-tin-dimethylglyoxime complex in which tin and technetium are intimately connected by a triple bridging arrangement. One bridge consists of a single oxygen atom and it is hypothesized that this bridge arises from the inner sphere reduction of technetium by tin(II), the electrons being transferred through a technetium "yl" oxygen which eventually becomes the bridging atom. Two additional bridges arise from two dimethylglyoxime ligands that function as bidentate nitrogen donors towards Tc and monodentate oxygen donors towards Sn. The tin atom can thus be viewed as providing a three-pronged "cap" on one end of the Tc-dimethylglyoxime complex. The additional coordination sites around Tc are occupied by the two nitrogens of a third dimethylglyoxime ligand, making the Tc seven-coordinate. The additional coordination sites around Sn are occupied by three chloride anions, giving the Sn a fac octahedral coordination environment. From indirect evidence the oxidation states of tin and technetium are tentatively assigned to be IV and V, respectively. Since most 99mTc-radiopharmaceuticals are synthesized by the tin(II) reduction of pertechnetate, it is likely that the Sn-O-Tc linkage described in this work is an important feature of the chemistry of these species. This linkage also provides a ready rationale for the close association of tin and technetium observed in many 99mTc-radiopharmaceuticals.


Segment-long-spacing aggregates and isolation of COOH-terminal peptides from type I procollagen. Type I procollagen secreted by matrix-free cells from chick embryo tendons was purified by DEAE-cellulose chromatography. Electron microscopy of segment-long-spacing aggregates of the procollagen demonstrated the presence of both NH2-terminal and COOH-terminal extensions not found in collagen. The procollagen was digested with bacterial collagenase and the COOH-terminal fragments were isolated by gel filtration and polyacrylamide gel electrophoresis in sodium dodecyl sulfate. Analysis of tryptic peptides demonstrated that the COOH-terminal extensions on the pro alpha 1 and pro alpha 2 chains had different primary structures.


Immunological characterization of the subunit of the 100 A filaments from muscle cells. We report the immunological characterization of the subunit of the intermediate sized (100 A) filaments from muscle cells. The protein as isolated from smooth muscle (chicken gizzard) has an apparent molecular weight of 50,000. It is insoluble in buffers that solubilize myosin and the majority of actin, but becomes soluble in the presence of urea. Under a variety of experimental conditions, that include the presence of 8 M urea, this new protein comigrates with actin during purification studies. The two proteins can be separated from each other by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, and antibodies have been elicited against the 50,000 dalton protein purified by using this technique. These antibodies crossreact with the partially purified protein in urea, but show no detectable cross reaction with actin or myosin. Indirect immunofluorescence reveals that in skeletal muscle this protein is found in close association with the Z lines of the sarcomeres and extends between the Z lines of adjacent myofibrils; it is also associated with filamentous structures that run along the length of a muscle fiber both in close association with the plasma membrane and between myofibrils at the level of their Z lines. In heart muscle, the protein shows the same distribution as in skeletal muscle. In addition, it is found intimately associated with intercalated disks and areas of membrane interaction between laterally associated heart muscle cells. The immunofluorescent localization to the subunit of the 100 A filaments suggests that in muscle cells this molecule may serve to link actin filaments at the level of the Z line (or intercalated disk) with the muscle plasma membrane. We believe that it functions in muscle primarily as a three dimensional matrix which interconnects individual myofibrils to one another and to the plasma membrane at the level of their Z lines. In this manner, this molecule may provide a framework that mechanically integrates all the contractile myofilaments during the contraction and relaxation of muscle. As a means of indicating its linking role in muscle, we have termed the protein desmin (from the Greek delta epsilon sigma mu os = link, bond).


Regulation of protein synthesis in rabbit reticulocyte lysates: purification and initial characterization of the cyclic 3':5'-AMP independent protein kinase of the heme-regulated translational inhibitor. The heme-regulated translational inhibitor (HRI) has been purified 4800-fold. On electrophoresis in sodium dodecyl sulfate/polyacrylamide gel, the purified HRI showed one major polypeptide band. The purified HRI inhibits protein synthesis in lysates containing optimal levels of hemin with inhibition kinetics which parallel those observed in heme-deficiency. Data are presented which are consistent with an enzymatic function of HRI in the inhibition of protein synthesis. The HRI is an adenosine 3':5'-cyclic monophosphate independent protein kinase which phosphorylates the small subunit (38,000) but not the large subunits (52,000 and 50,000) of the initiation factor which forms a ternary complex with Met-tRNAf and GTP. This evidence supports the hypothesis that inhibition of protein synthesis by HRI involves the phosphorylation of the initiation factor. These findings are discussed in relation to various models for the regulation of protein kinase activity by heme. (see article).


DNA unwinding component of the nonhistone chromatin proteins. A subclass of nonhistone chromatin proteins from rat liver, previously shown to exhibit high affinity for DNA, has been fractionated by single-stranded DNA-agarose affinity chromatography. The protein fraction that bound to DNA-agarose in 0.19 M NaCl-buffer and was eluted with 2 M NaCl-buffer is enriched for a protein component of approximately 20,000 daltons and exhibits preferential binding to denatured DNA. This nonhistone protein fraction specific for single strands binds to DNA in a non-species-specific manner, and causes helix-coil transition of synthetic poly[d(A-T)-d(A-T)] at 25 degrees, as indicated by the increase in absorbance of ultraviolet light at 260 nm. The observed hyperchromicity does not result from any nuclease activity in the protein fraction, because addition of Mg+2 results in partial hypochromic shift, and the protein/DNA complex is retained by nitrocellulose filters.


Interactions of heterologous nitrogenase components that generate catalytically inactive complexes. A unique method is described for inhibiting nitrogenase. When Clostridium pasteurianum nitrogenase is assayed in the presence of the Mo-Fe protein of Azotobacter vinelandii, all the characteristic activities of nitrogenase are inhibited. C. pasteurianum nitrogenase is unaffected by the Fe protein of A. vinelandii. The Fe protein, but not the Mo-Fe protein of C. pasteurianum, inhibits A. vinelandii nitrogenase. Both inhibitions described result from the formation of an inactive complex of A. vinelandii Mo-Fe protein and C. pasteurianum Fe protein. Complex formation requires active components, as oxygen-denatured proteins are ineffective. The results for titration of components of the complex against each other and kinetic data each indicate that the inactive complex consists of two molecules of C. pasteurianum Fe protein per molecule of A. vinelandii Mo-Fe protein. The results of kinetic experiments suggest that the Fe protein from each organism competes for the same site(s) on the A. vinelandii Mo-Fe protein. The Fe protein of C. pasteurianum will form an active or an inactive complex with the Mo-Fe proteins from six different organisms. Inhibition by nitrogenase components that form inactive complexes provides numeroius ways to study the mechanism of nitrogenase action.


Amino-terminal sequences of two polypeptides from human serum with nonsuppressible insulin-like and cell-growth-promoting activities: evidence for structural homology with insulin B chain. The amino-terminal sequences of two polypeptides with nonsuppressible insulin-like and cell-growth-promoting activities (NSILA I and II), isolated from human serum, were determined. Of the first 31 residues, 22 are identical in NSILA I and II. Moreover, a striking structural similarity was found between NSILA and insulin B chain: 47 and 57% of residues 1-30 in NSILA I are identical to those in insulin B chain from man and tuna fish, respectively. This high degree of sequence identity is presented as evidence for homology and thus for a common evolutionary origin of insulin and NSILA. Based on these results and on these results and on biological properties of NSILA described earlier, a new designation for NSILA is proposed: insulin-like growth factor (IGF).


Brain tubulin polymerization in the absence of "microtubule-associated proteins". Pure tubulin dimer, purified by phosphecellulose chromatography to remove microtubule associated proteins, can be assembled into microtubules in the presence of dimethyl sulfoxide. The surfaces of such microtubules are devoid of filamentous material. The reaction is rapid and strongly dependent on protein concentration. No microtubule formation occurs from the purified tubulin when dimethyl sulfoxide is omitted.


Histones H3 and H4 interact with the ends of nucleosome DNA. Isolated HeLa cell nucleosomes (core particles) were labeled at the 5'-termini of their DNA with 32P using [gamma-32P]ATP and polynucleotide kne by sequential methylation, depurination, Schiff base formation, and reduction with sodium borhydride. After digestion of the noncrosslinked DNA by DNase I and venom phosphodiesterase, histones were separated by gel electrophoresis and those crosslinked to the 5'-termini were identified by 32P-autoradiography. Histones H3 and H4 occur with equeal frequency as the nearest protein neighbors to the end of the DNA in nucleosomes. Histone arrangements within the core particle compatible with these results are discussed.


Coupling of catecholamine receptor from one cell with adenylate cyclase from another cell by cell fusion. The experiments test the hypothesis that beta-adrenergic receptor is an independent unit that can be transferred from one adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4-6-1-1[ system to another. Turkey erythrocytes in which the catalytic activity of adenylate cyclase had been inactivated by N-ethylmaleimide or by heat contributed the beta-adrenergic receptor. Friend erythroleukemia cells (F cells) that possessed no measurable beta-adrenergic receptor contributed the adenylate cyclase. The erythrocytes in which the enzyme had been inactivated were fused with the F cells by Sendai virus. The cell ghosts of the fused preparation demonstrated adenylate cyclase activity which was strikingly enhanced by isoproterenol. Controls of fusion of F cells with each other or with human erythrocytes failed to show a response to isoproterenol. It was therefore concluded that the beta-adrenergic receptor of the turkey erythrocytes must have become functionally coupled to the adenylate cyclase of the mouse F cells. Activation by isoproterenol was demonstrable within a few minutes after fusion, and inhibitors of protein synthesis had no effect. Thus, coupling must have occurred between the preexisting components. The findings suggest that it may be possible in the future to confer on cells that possess an adenylate cyclase system new hormonal responses by inserting a receptor into their cell membrane. It is proposed that the procedure of massive heterologous cell fusion, as used in the present study, can be used to analyze the function of other cell membrane components.


Synthesis of type II collagen in vitro by embryonic chick neural retina tissue. Collagen produced by chick neural retina tissue in vitro has the properties of type II collagen. Isolated neural retina tissue from stage 29-32 chick embryos incorporated [14C]glycine and [3H]proline into collagen consisting of alpha1 chains and a higher molecular weight species. The peptides produced by cyanogen bromide digestion of the collagen are identical to those from authentic type II collagen from cartilage in charge properties, as determined by carboxymethyl-cellulose chromatography, and size distribution, as determined by sodium dodecyl sulfate-acrylamide gel electrophoresis.


Steady-state kinetic formalism applied to multienzyme complexes, oxidative phosphorylation, and interacting enzymes. A kinetic formalism, quite generally valid for free energy transducing, steady-state, macromolecular systems in biology, is applied here to multienzyme complexes, oxidative phosphorylation, and interacting enzymes. Systems of this type, comprising several interacting subunits, each with its own discrete set of states, present no new features in principle. Hence, they may be handled by the earlier kinetic formalism without modification. However, the kinetic diagram can become quite complicated because the state of each subunit (enzyme) must be specified in order to specify any one state of the system (complex) as a whole. Cycles, forces, fluxes, free energy levels, and state probabilities are considered.


Translation of turnip yellow mosaic virus RNA in vitro: a closed and an open coat protein cistron. Sucrose gradient centrifugation of heat-denatured RNA of turnip yellow mosaic virus permitted the isolation of five RNA classes with molecular weights ranging from 2.0 to 0.25 X 10(6). The infectivity was shown to be confined to an RNA molecule of molecular weight 2.0 X 10(6). No significant increase in infectivity was obtained by combination of the latter RNA with the RNA classes of smaller size. Translation in vitro of the RNAs of different size classes in a wheat germ cell-free system revealed that the infectious RNA (molecular weight 2.0 X 10(6) does not promote the synthesis of the coat protein of turnip yellow mosaic virus. Efficient production of this coat protein was found exclusively when the smallest RNA class (molecular weight 250,000) was used as a messenger. It is concluded that RNA molecules of turnip yellow mosaic virus of molecular weight 2.0 X 10(6) contain a closed coat protein cistron and that RNA molecules of molecular weight about 2 to 3 X 10(5) with an open coat protein cistron can be isolated from the virions.


Changes in cellular glycoproteins after transformation: identification of specific glycoproteins and antigens in sodium dodecyl sulfate gels. The glycoproteins of whole cells have been analyzed by direct application of radio-iodinated lectins to sodium dodecyl sulfate gels, followed by autoradiography. By use of lectins with different carbohydrate specificities, different sets of glycoproteins have been visualized. The most prominent lectin-binding band in many gels is thelarge, external, transformation-sensitive (LETS) protein. Major glycoprotein differences are revealed when normal and virus-transformed cells are compared. Certain differences, however, are also seen when the glycoproteins are compared from two separately derived simian virus 40 transformants of 3T3 cells, suggesting a degree of clonal variation between these lines that may not relate to transformation. A complementary technique is used to detect specific antigens in sodium dodecyl sulfate gels by direct application of iodinated antibodies. An antiserum specific for the LETS protein is used to identify this antigen in the gels of both normal and transformed cells.


Photoaffinity site-specific covalent labeling of human corticosteroid-binding globulin. A method was developed for the synthesis of high-specific-activity 21-diazo-21-[6,7-(3)H]deoxycorticosterone, an analog of corticosterone. This analog was used as a photoaffinity label of a high affinity steroid-binding protein, human corticosteroid-binding globulin. Based on direct binding studies and crosscompetition experiments, this diazo derivative exhibited the requisite affinity (within a factor of 1.5 times that of corticosterone) and site specificity to qualify as an affinity labeling legand. Irradiation of corticosteroid-binding globulin with the 21-diazo derivative resulted in irreversible binding to corticosteroid-binding globulin, identified by polyacrylamide gel electrophoresis. Specificity of covalent binding to corticosteroid-binding globulin was established by competition analysis with various steroids. Irreversibility of photodependent binding was shown by persistence of the complex on electrophoresis (in contrast to the noncovalently linked complex), and resistance to exchange with corticosterone or pregnanediol and to solvent extraction. Site specificity of covalent binding was inferred from the effects of a scavenger, Tris-HC1, and fluorescence quenching of a neighboring tryptophan.


Modification of adenylate cyclase activity in LM cells by manipulation of the membrane phospholipid composition in vivo. Adenylate cyclase [atp pyrophosphate-lyase (cyclizing): EC 4.6.4.4] activities were examined in mouse LM cell (fibroblast) membranes that were supplemented with ethanolamine and/or fatty acids. The supplements were incorporated into the plasma membrane phospholipids in significant amounts. Fatty acid supplementations had distinct effects as compared to polar head group supplementations. All lipid supplementations increased basal adenylate cyclase activity relative to control cells grown in choline-containing medium. Double supplementation with ethanolamine and linoleate increased the specific activity of adenylate cyclase up to 4-fold. Activity in the presence of fluoride was unaffected by ethanolamine supplementation, but was increased by fatty acid supplementation. In contrast, prostaglandin E1 stimulation was 4.2-fold in controls and ethanolamine and/or elaidate supplements, 6-fold in choline plus linoleate supplements, and 3.1-fold in ethanolamine plus linoleate supplements. Differences in activity could not be ascribed to changes in membrane protein composition in supplemented cells, and could be abolished by detergent solublization. Fluidity of the supplemented membranes was monitored by fluorescence polarization, and no correlation was observed between membrane viscosity and adenylate cyclase activity or hormone stimulation. These results emphasize the importance of the membrane lipid phase for this enzyme.


Rate of quaternary structure change in hemoglobin measured by modulated excitation. Using a novel technique of modulated photo-dissociation of carbon monoxide from hemoglobin, we have obtained the rates for conversion between the two quaternary states, R, and T, at 3-fold ligation. Our measurements at pH 7 and 22 degrees give rates of 780 +/- 40 sec-1 for going from R to T, and 2500 +/- 200 sec-1 from T to R. This yields an equilibrium constant of 0.31 +/- 0.04, which is in good agreement with previous estimates. The degree of agreement between this equilibrium constant and that predicted from the allosteric model provides a new, quantitative test of the allosteric description. A sequential model for the change in structure was found incompatible with the data, even if kinetic subunit inequivalence was assumed. The technique described here is quite general and can be used as long as the system under investigation can be repetitively excited in a regime in which it responds linearly to the excitation.


Innervation of heart cells in culture by an endogenous source of cholinergic neurons. Hearts of embryonic mice 9 days in utero were found to have an endogenous source of cholinergic neurons which can survive in dispersed cell cultures. These neurons are electrically excitable, have ultrastructural characteristics of cholinergic embryonic neurons, and functionally innervate heart cells in culture. The nature of the innervation described is muscarinic cholinergic.


Vertical displacement of membrane proteins mediated by changes in microviscosity. Membrane proteins of intact human erythrocytes were labeled with two fluorescent sulfhydryl reagents. The tagged cells were then subjected to simultaneous liposome treatments for either depletion or enrichment of membrane cholesterol content. Cholesterol depletion, which reduces membrane microviscosity, was followed by a series of fluorescence changes all indicating masking of the membrane proteins. Conversely increasing the membrane microviscosity by cholesterol enrichment resulted in an appreciable increase of the protein exposure to the aqueous surrounding. These findings strongly suggest that membrane proteins may be vertically displaced upon changes in lipid fluidity, a mechanism that may play a significant role in modulation of antigens and receptors in vivo.