Occlusal and craniofacial growth changes during puberty.
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Changes in dental arch size and form were assessed by means of univariate and multivariate analysis in a longitudinal study of children between 2 and 10 years of age. The multivariate analysis served to assess the arches as a biologic whole rather than as a series of independent dimensions. Dental arches do not seem to undergo a steady rate of change up to the age of 10 years. In the arches anterior to the first permanent molars, peaks of growth occur between 2 and 3 years and 7 and 8 years in the maxilla, and between 2 and 3 years and 5 and 6 years in the mandible. In the arches, including the first permanent molars, peaks of growth occur between 6 and 8 years in the maxilla and between 9 and 10 years in the mandible.
Agrobacterium sp. and related species which in the soil and in the rhizosphere of wheat accompany the fungus Gaemannomyces graminis var. tritici and cause take-all of the wheat roots produced polysaccharides in pure cultures (glucans, mannoglucans and galactomannoglucans). These polysaccharides were utilized better by the mycelium of G. graminis than glucose and polysaccharides of plant origin that occurred on the surface of wheat roots (the so-called mucigel). At lower concentrations these bacterial polysaccharides stimulated growth of wheat roots, higher concentrations (more than 0.1%) were inhibitory. Bacteria inoculated on the surface of wheat first inhibited and then stimulated the development of the plants and their growth. Changes in the growth rate of wheat, the rhizosphere of which was colonized by bacteria simultaneously with the fungus G. graminis and also some changes in the course of the disease of wheat roots caused by the fungus can be explained by the inhibitory or stimulatory effect of polysaccharides of accompanying bacteria.
1. Age-, sex-, and growth-type-specific craniofacial templates represent a practical approach to orthodontic case analyses and craniofacial growth. 2. The Burlington Growth Centre Cephalometric Analysis is a practical adjunct to treatment planning. 3. This cephalometric analysis, which combines many analyses, is an assessment of the relative proportions of the face in length, width, and height (static analysis) and an estimation of the future changes (dynamic analysis). 4. As an aid in diagnosis, the template and/or analysis in conjunction with a cephalogram, with provide information pertaining to (q) cranial base length angle, (b) upper and lower face height and maxillary and mandibular height, (c) size and proportions of the facial bones, both anteroposteriorly and in width, (d) denture relationship, both anteroposteriorly and in width, and (e) expected general growth changes.
The cephalometric records of sixty-four Class II, Division 1 cases treated exclusively with removable orthodontic appliances have been used in a study of the manner in which maxillary central incisors tilt. The center of rotation was most frequently located in the middle third of the incisor root. The longer the time interval between the pre- and posttreatment cephalograms, the more apical was the rotation axis likely to be, an effect ascribed to growth changes in the maxilla. If the effects of growth are taken into account, it seems that the maxillary central incisor seldom, if ever, tilts about the apical third of its root when force levels customarily recommended for tipping movements are employed. The results suggest that the instantaneous and orthodontic centers of rotation are one and the same and support the view that the manner in which incisor teeth move in response to a single applied force depends principally on the physical properties of the tooth root, supporting bone, and periodontal membrane. An unexplained correlation was found between the rate of incisor movement measured at the cervical margin of the tooth and the level of the rotation center.
1. The cuspid width is most likely to decrease after treatment (9 of 11) although on occasion a slight increase (2 of 11) was maintained. 2. The molar width is apt to decrease from the beginning of treatment through the postretention period. 3. The cephalometric measurements studied in this sample of good stable occlusions coincided with with the norms and ranges as used by R.M. 4. The age changes of the various cephalometric measurements also agreed with the age changes that R.M. utilize. 5. Lower arch crowding may be due to multiple factors of expanded cuspids, protrusive and labially inclined mandibular incisors, and late skeletal growth changes.
A comparison has been made of cases treated with deliberate anchorage preparation (Class III elastic mechanics) prior to Class II elastic mechanics and cases treated with Class II elastic mechanics only. Treatment goals were the same. Extraoral traction was used as necessary to achieve those goals. Appliance quantity and size were the same. Age, sex, and severity of malocclusion were comparable. It remained that the anchorage-prepared cases demonstrated a flattening of the mandibular plane, greater retraction of the lower incisors, more retraction of midface, and more protraction of lower face. These changes of lower face are consistent with the normal growth changes of the human face.
The minimal antbiotic concentration (MAC) refers to the lowest concentration of drug that results in a detectable effect on bacteria (e.g., inhibition of growth, change in morphology, and delay in recovery to normal growth in drug-free medium). Strains of Escherichia coli and Staphylococcus aureus were subjected to a range of subminimal inhibitory concentrations of four drugs-ampicillin, gentamicin, rosaramicin, and tetracycline. Inhibition curves (percentage of normal growth vs. concentration of drug) were related to the period of recovery before resumption of normal growth, which was chosen to express MAC value. In both E. coli and S. aureus, the longest delay in recovery of normal growth was observed with rosaramicin. Ampicillin resulted in a delay in recovery only with S. aureus.
Ascitic fluid and ascites tumor cells from Swiss mice bearing Ehrlich ascites tumor were assayed for components of the kallikrein-kinin system at various times during tumor growth. Changes in component levels were correlated with those in the plasma. Ascitic fluid contained an acetone-activated prekallikrein that increased in concentration during tumor growth and reached peak levels during the 7th-10th day post transplant. No free kinin activity was present in the ascitic fluid. During tumor growth, kininogen levels increased in parallel with prekallikrein levels. The ascitic fluid also contained a kinin-destroying activity that was initially high during the early phase of tumor growth. Tumor cell fractions, prepared by ultracentrifugal techniques, had no kinin-forming activity while possessing kinin-destroying activity that was localized in the soluble protoplasmic protein and nuclear fractions. The kinin-forming activity of the ascitic fluid resembled that of the plasma with respect to pH optima, kinetics of kinin formation, and effect of protease inhibitors. The kininase activity of both ascitic fluid and plasma differed from that of the tumor cell fractions.
Changes in the capacity of mitochondria to carry out oxidative phosphorylation and in the rate of synthesis and incorporation of phospholipids into mitochondria were measured during the germination of conidiospores of Neurospora crassa. The competence of isolated mitochondria to carry out coupled respiration was very low during the first 3 h growth, but it increased rapidly, reaching maximal levels at 5 to 6 h growth. Changes in mitochondrial function were the same in cells grown in 2% sucrose- or 15% glucose-supplemented medium. The rate of synthesis of mitochondrial phospholipids was very low during the first 2 h growth and increased to maximal levels between 3 and 5 h. The rate of synthesis of mitochondrial phospholipids was approximately three times higher in cells grown in 15% glucose than in those grown in 2% sucrose. The maximal rate of synthesis of mitochondrial phospholipids occurred during spore germination and preceded attainment of full competence for oxidative phosphorylation. The lipid-rich condition of the mitochondrial resulting from the high rate of synthesis of phospholipids in glucose-grown cells is postulated to be related to the whorled inclusions observed in thin sections of Neurospora cells.
The effects of an artificial diet on growth were examined in a controlled trial on 43 patients with cystic fibrosis. 28 patients received the diet for 12 months. Comparison was made between their growth before, during, and after dietary treatment. Growth changes were also assessed in 15 other patients who received a conventional diet. Artificial dietary treatment led to some improvement in height, weight, subscapular skinfold thickness, and a disproportionate advance of bone age for the group as a whole. Only 10 (36%) patients had a 'clinically' significant improvement in height, weight, or both--i.e. more than 0.5 standard deviation score. Greatest improvements were in young and mildly affected patients. It is proposed that the future use of such an unpleasant and expensive diet should be restricted to a few selected cases, rather than given as routine treatment.
The effect of interference in the neonatal critical period on water and salt solution (3% NaCl) intake by adult rats given a free choice of these fluids was studied. Consumption was expressed per animal, per 100 g body weight and as the NaCl concentration in the total daily fluid intake volume [NaCl]I. Newborn female rats were ovarectomized or sham-ovarectomized. Ovarectomy markedly reduces consumption and [NaCl]I in adulthood and brought these values close to the values in normal males. Newborn male rats were injected with 1 mg oestradiol propionate dissolved in oil or just with oil. Oestradiol propionate severely inhibited growth, but produced no changes in fluid intake per animal. The [NaCl]I values were likewise unaltered, but owing to the lower body weight comsumption values per 100 g b.w. were higher in rats given oestradiol propionate than in those given oil. The relationship of the given growth changes to the regulation of salt intake and to hypothalamic function and its sexual correlates is discussed.
Synthesis and turnover of the main structural protein (P73) of intracisternal A-particles were studied in mouse neuroblastoma cells in tissue culture. Triton X-100:EDTA-insoluble pellets containing 95% of the A-particle antigen in the cells were prepared and analyzed by electrophoresis in Na dodecyl-SO4-minus polyacrylamide gels. A 73,000 molecular weight component was prominent in pellets from three lines of neuroblastoma which contain numerous A-particles and this component was identified as the A-particle structural protein P73. It was absent in pellets prepared from cells which do not contain A-particles. Incorporation of labeled amino acids into P73 represented approximately 1.2% of total cell incorporation and this proportion did not change when the cell growth changed from log phase to stationary phase. Label appeared P73 within 2 min after radioactive amino acids were added to the medium. Pulse-chase and inhibitor studies confirmed antigenic measurements in demonstrating that the pool of P73 not assembled into A-particles was small. Turnover studies showed that P73 gained and lost label more rapidly than the average cell protein. In one cell line which was thoroughly characterized, approximately 60% of the main A-particle protein was estimated to turn over in a 24-hour period. Although the cells released approximately 10% of the proteins synthesized into the culture fluid, A-particle protein did not appear to be released. Analysis of culture fluid failed to reveal A-particles, soluble A-particle proteins, or A-particle antigen. It appears, therefore, that the particles are relatively rapidly synthesized and degraded, and that turnover occurs entirely intracellularly.
Growth changes associated with formation of the secondary palate were studied in H-Velaz mouse embryos by morphometric measurement of medial sagittal sections of the heads between days 13 and 15 of embryonic development. Horizontalization of the palatine processes depends primarily on the length of the mandible and is effected by a shift of palatine process material into the supralingual space. The administration of 7.5 mg cortisone acetate im to the female on day 12, of 0.5 mg 6-aminonicotinamide im on day 14, or amniocentesis on day 14 significantly retards growth of the embryo in general and of the mandible in particular without significantly affecting deflexion of the skull base. The different spatial conditions created by disproportion between deflexion of the base and the length of the mandible cause irregularities in the course of horizontalization which lead, as a rule, to cleft palate.