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With special training and experience, many pediatric dentists are at the forefront in the care of the special population groups: the developmentally disabled; the chronically and the acutely ill; the hospitalized patient; the high-risk patient; and a variety of others with special needs.
Children with special pathology, such as clefts and scoliosis, must be managed at a special centre until a comprehensive treatment strategy has been developed and appropriate therapeutic measures undertaken. Examinations were performed in 375 children, who were then distributed into three groups: patients with clefts (group A), scoliosis (group B) and no special pathology (group C). Monomaxillary therapy was used most frequently in the group with clefts and bimaxillary therapy in the group with scoliosis. In patients with scoliosis extractions of permanent teeth should be avoided in order to preserve a maximum number of occlusal units, since they transmit forces from the brace to the skull, especially during sleep. Groups A and C revealed an increase in the number of adults, including new patients and patients who resumed treatment after it had been interrupted. These patients are very cooperative and the results of corrective treatment are extremely favourable.
Recent research in which investigators examined cerebral specialization in individuals with Down syndrome was reviewed. Although dichotic listening studies seem to indicate that individuals with Down syndrome are more likely than those without Down syndrome to display a left ear/right hemisphere advantage for speech sounds, evidence from other experimental paradigms makes a simple model of reversed cerebral specialization for individuals with Down syndrome untenable. We proposed a model of cerebral specialization that has as its main feature the biological dissociation between speech perception and the production of speech and other complex movements. In light of this feature, possible directions for future research were discussed.
The final development of specializations by brain capillary endothelial cells, which characterize them as distinct from non-central nervous system (CNS) endothelium, is thought to be controlled by astrocyte-derived factors produced locally within the CNS. One specialization, the complex intercellular tight junction, which is unique to these cells and a major component of the blood-brain barrier, is controlled by an astrocyte-derived factor(s) and a "competent' extracellular matrix (Arthur et al., 1987). In order to test whether these factors can also trigger development of brain endothelium-like tight junctions in non-CNS microvessel endothelial cells, passaged bovine aorta and pulmonary artery endothelial cells were cultured in either 50% astrocyte-conditioned medium and 50% alpha-MEM, or in alpha-MEM alone (control). Only endothelial cells maintained in conditioned medium exhibited ultrastructural features indicative of synthesis and plasma membrane-insertion of junction components (Shivers et al., 1985). No assembled tight junctions were seen in these cells. Endothelial cells plated onto coverslips coated with ECM (Cedarlane Labs., Hornby, Ont.) and maintained in astrocyte-conditioned medium, displayed large, complex tight junctions and extraordinarily large gap junctions. Cells plated onto plastic or fibronectin-coated substrates possessed no tight or gap junctions. Results of this study show that CNS astrocytes produce a soluble factor(s) that promotes synthesis and insertion of tight junction components in non-CNS endothelial cells. Moreover, an intact, endothelial-derived extracellular matrix is required for assembly of tight junctions to complete development of this brain capillary-like specialization. This study confirms the notions that: a) the final fine-tuning of cell differentiation is under local control, and b) that endothelial cells in general do not express their final destination-specific differentiated features until those features are induced by local environment-produced conditions.
Diphtheria, tetanus, and pertussis (DTP) immunization data were collected on 103 special care nursery graduates in our neonatal follow-up clinic to determine whether DTP immunization schedules were significantly delayed relative to recommendations of the American Academy of Pediatrics (2, 4, and 6 months for DTP 1, 2, and 3, respectively). An inverse correlation was found between birth weight and immunization for first, second, and third DTP (r = 0.319, P less than .01; r = .205, P less than .05; and r = .236, P less than .05, respectively). We subsequently conducted a mail survey to determine the DTP immunization policy present in effect in 25 neonatal intensive care units in the United States and Canada. The survey indicates that procedural approaches remain markedly heterogeneous, and 10 of 25 (40%) units have no existing policy for implementation of DTP immunization. These data suggest that special care nursery populations are at potential risk for pertussis, which requires a conscious implementation of DTP immunization by the special care nursery, the follow-up clinic personnel, and the primary care physician.
The ferritin family is a widespread group of proteins that maintain iron in a soluble form and also protect against the toxic effects of excess iron. The structure and sequence of the proteins are highly conserved. However, the cell-specific features of structure which occur within the same organism indicate cell specificity of gene expression and may be related to variations in types of iron storage, i.e. specialized-cell ferritin (stored iron is for other cell types) versus housekeeping ferritin (stored iron is for intracellular purposes related to normal or stress metabolism); the protein structure may also affect rates of iron turnover. Iron induces ferritin synthesis and accumulation by recruiting stored ferritin mRNA that is efficiently translated in cells specialized for iron storage. For the first time we show the occurrence of three different cDNAs from bullfrog tadpoles, corresponding to three subunits of the protein: H, M, and L. Thus, ferritin can be encoded by at least three different mRNAs and probably three different genes, in contrast to the older idea of two, H and L; the subunits maintain the conserved sequences of known ferritins and have similar predicted masses, 20.5, 20.6, and 19.9 kDa, but have distinct mobilities in denaturing gels. Ferritin subunit expression is cell specific; more of the H and L chain mRNAs are expressed in red cells than in liver. Ferritin expression is regulated by transcription (or mRNA stability) in adult red cells; cellular levels of ferritin mRNA were 20% that of embryonic red cells, and L subunit mRNA increased 2.5 times with excess iron. Ferritin expression is also regulated during translation in adult red cells; iron recruits stored ferritin mRNA, but only during certain stages of red cell maturation, in contrast to embryonic red cells. The developmental differences in ferritin expression are discussed in relation to the shift from specialized-cell ferritin to housekeeping ferritin in red cells of the embryonic versus adult lines.
The composition of specialized formulas for infants who experience malabsorption or formula intolerance is described in detail. The limited studies of efficacy, as well as a rationale for selecting an appropriate formula for infants with malabsorption or formula intolerance, are discussed. Infants with symptoms of diarrhea or emesis may have intolerance to milk lactose or milk protein. Soy formulas contain no lactose or cow's milk and should be the first choice of an alternative feeding because of cost and convenience. Some infants may be intolerant of soy as well as cow's milk protein. They benefit from formula containing neither cow's milk nor soy protein or from a specially processed milk-based formula containing hydrolyzed casein. A carbohydrate-free formula to which the desired type of carbohydrate is added may be helpful in the diagnosis and treatment of disaccharidase deficiencies and monosaccharide intolerances. Infants with extensive intestinal resections or intractable diarrhea may require specialized infant formulas with qualitative/quantitative modifications of fat, carbohydrate, and protein. Formulas with medium-chain triglycerides may be useful for infants with steatorrhea. "Preterm" formulas or milk from the infant's mother are preferred for preterm infants, since such feedings promote improved fat and carbohydrate absorption and better meet the infant's nutrient requirements.
Many animal species demonstrate a keen sensitivity very early in life to stimuli that play a role in their survival. Theorists have taken this to mean that species-specific mechanisms evolved in animals that aid in the detection and recognition of important stimuli. Similar arguments have been made about the mechanisms that underlie the perception of speech in humans. Theories of speech perception present convincing arguments that even the phonetic level of language requires specially evolved mechanisms, because of the extreme complexity involved in the mapping between sound and percept. Phenomena such as categorical perception have been attributed to the workings of these mechanisms. This paper lays out an argument concerning the contribution of animal studies on categorical perception to the special-mechanisms debate. Animals provide a model of auditory-level processing in the absence of phonetic-level processing, and test whether the existence of a phenomenon such as categorical perception necessitates specialized mechanisms. A review of the studies shows that animal demonstrate categorical perception of the voicing and place features. These data, as well as some recent findings on young human infants, are considered with regard to their impact on theories of infant speech perception and on the evolution of speech.
Special resuscitation situations are cardiopulmonary arrests requiring modification or extension of conventional life support techniques. Significant controversy exists with regard to several aspects of special resuscitation, including whether or not there is a need to clear the airway of a near-drowning victim with the Heimlich maneuver and whether CPR should be initiated in an unmonitored hypothermic patient showing no signs of life. The previous standards and guidelines almost entirely neglected the management of cardiac arrest due to traumatic injury. The conference panel on Special Situations recommended that: the Heimlich maneuver should only be performed on near-drowning victims when the rescuer suspects that foreign matter is obstructing the airway or the victim fails to respond appropriately to mouth-to-mouth ventilation, further investigation is needed to better define the need for, the risks of, and the timing of the Heimlich in the near-drowning victim, there should be an expanded section in the standards and guidelines describing the differences in the management of a victim whose cardiac arrest is due to traumatic injury, CPR is indicated and should be done on a pulseless, unmonitored hypothermic patient in the field, but that a longer time to check for a pulse (up to one minute) may be required, and guidelines that the panel proposed be used for management of the underwater submersion victim in cardiac arrest.
A specialized foot clinic for diabetic patients has made a detailed analysis of the presentation of diabetic foot ulcers and from this a new, organised approach to treatment has been derived. Over three years it has achieved a high rate of ulcer healing and reduced the number of major amputations. It has brought together the skills of chiropodist, shoe-fitter, nurse, physician and surgeon to manage the distinctive lesions of the neuropathic and ischaemic diabetic foot. The neuropathic ulcer was invariably associated with callus, whereas the ischaemic ulcer presented as areas of necrosis often from localised pressure of tight shoes. Essential aspects of management are specially constructed shoes, intensive chiropody and precise antibiotic treatment. Healing was achieved in 204 out of 238 (86 per cent) neuropathic ulcers and 107 out of 148 (72 per cent) ischaemic ulcers. Relapse rate in special shoes was 26 per cent compared with 83 per cent who preferred to wear their own shoes. In the two years before the establishment of the clinic, there were 11 and 12 major amputations yearly. This rate has now been reduced to seven, seven and five amputations yearly.
The large number of rheumatic diseases demands a clear differentiation between the individual forms of diseases. For this purpose are at first necessary knowledge concerning clinical criteria and in the second place knowledge about serological and radiological examinations. The serological programme shall be relevant to practice, consist of a basis diagnostics and for particular differential-diagnostic problems shall include specialized laboratory investigations. Necessary X-ray pictures must be performed with a special aim and comparison of the sides. For therapy the interdisciplinary team work, consisting in the cooperation of rheumatologists, orthopedic surgeons, specialized surgeons and physiotherapists stood the test. An important prerequisite is also the cooperation of the outpatient and inpatient rheumatological institution. For a complex rehabilitation programme apart from the physicians experienced coworkers for tasks of welfare, ergotherapy and physiotherapy are necessary.
The paraformaldehyde-fixed hearts of adult rats were embedded in paraffin. Serial sections throughout the interatrial septum and the atrioventricular junction were examined in the optical microscope after having been silver stained. The density and the distribution of different nervous elements in the perinodal nerve plexus were studied and the results compared with the electron-microscopic data. These data confirm that at the level of the atrioventricular junction, a dense terminal network can be seen. It is composed of both terminal nerve fibers and ganglionic cells forming a small ganglion adjacent to the lower edge of the bundle of His and a thin ganglionic lamina in the interatrial septum. Apart from small neurons, previously described as cholinergic, large neurosecretory cells could also be demonstrated in some of the serial thin sections through the Hissian ganglion. The neuromuscular junctions between the terminal nerve fibers and specialized cells exhibit regional specialization. While the distal portion of the atrioventricular node and the bundle of His receive essentially efferent fibers, afferent coiled endings prevail in the reticular portion of the atrioventricular node and in the adjacent interatrial septum. Similar structures, larger in diameter, can also be seen around the muscular fibers and around the capillaries of the interventricular septum. The functional significance of the aforedescribed regional specialization of the terminal innervation of the atrioventricular junction is briefly discussed.
In 1977, 7% of the 38,855 infants born in Utah were estimated to have required a total of 27,439 special-care hospital days. About half (53%) were mildly ill; their average length of stay was 4.6 days, or 24% of the total hospital-days. Another 20% of the infants had intermediate illness, with a 12-day average stay, or 23% of the total hospital-days. The remaining 27% of the infants required intensive care and used 53% of the total hospital-days; their average length of stay was 20 days. As a total population, the state's 38,855 births generated a need for two beds per 1,000 annual live births in special-care facilities. The estimated bed need was: mild illness (Level I), 0.5 beds per 1,000 annual live births; intermediate illness (Level II), 0.5 beds per 1,000 annual live births; and intense illness (Level III), one bed per 1,000 annual live births. Results are based on the assumption that nonstudy births, 30% of the total, have needs proportionate to study births. The following considerations are necessary to extrapolate these bed needs to other populations: convalescence of intensely ill babies may require that up to 50% of their bed needs may be shifted to intermediate care; compliance with criteria for transport to the next level of care may not be 100% as assumed in the study, thus redistributing bed needs; census characteristically fluctuates in special-care nurseries (study results are reported for an unchanging daily census); and the low birth rate of a population is intimately related to the bed needs.
A method of charging for pharmaceutical services is described which includes the cost of drug products, dispensing fees for intravenous drug admixtures, per diem fees for basic dispensing and clinical services (according to patient type), and fees for special clinical services. The basic per diem charge covers drug purchasing and inventory control, department management, drug information services, dose preparation, drug order interpretation, drug therapy monitoring, and the availability of pharmacists to answer the questions of nurses and physicians. The clinical services for which special fees are charged are: hemogram drug report, drug liver function report, aminoglycoside dosing guidelines, heparin i.v. infusion, oral anticoagulation, patient drug history, operant conditioning, parenteral nutrition guidelines, and pharmacokinetic drug level interpretations and consultations. The reasons for changing to the system, the services provided and experiences with the system are discussed. Implementation of the system is discussed in relation to the calculation of fees; comparisons with alternate charging methods; approval of special clinical service charges; computer billing; information about pharmacy charges for patients; and third-party payers.
The structure, cellular composition and organization of the small intestinal epithelium of adult Xenopus laevis are described. The mucosa is thrown into a system of longitudinal folds and is composed mainly of columnar cells and goblet cells. Leucocytes comprise about 28% of the mucosal cells. The degree of structural specialization of columnar cells varies according to their position in the folds. Cells at the crest of the folds display the greastest degree of specialization, evidenced by the degree of development of their inter- and intracellular membrane systems. Cells in the trough regions between the folds are much less specialized. These cell types are structurally analogous to mammalian villous and crypt cells respectively, although they are not segregated to the same degree.
The development of neuropathology into a special working field began in the second half of the 19th century in accordance with the clinical requirements arising from an increasingly scientific approach to mental and nervous diseases. The progress made also in this discipline is based on improved methods and the nervous system can only be understood from its interactions with other organs and the environment. The subject of the study and special relations to clinical and theoretical branches as well as morphological working and thinking are the basis of a subspecialisation of Neuropathology with an integration into General Pathology and Special Pathological Anatomy, in order to avoid an isolation.
A light-optic and electron-microscopic study of internodal specialized pathways in the rat interatrial cardiac septum is reported. The topography of conductive pathways is described. Morphometric investigation yielded comparative quantitative characteristics of tissue and cellular composition of the working and conductive septal myocardium. A single type of myocytes was demonstrated in specialized conductive pathways. The findings were compared with those obtained in other species. Principles of identification of specialized conductive pathways are discussed.
The review contains some literary evidence and the authors' own data on the ultrastructure and molecular organization of specialized intercellular junctions (tight, septate, intermediate, gap junctions and desmosomes). The analysis of structural organization of junctions was carried out using data obtained by various electron microscopic techniques (ultrathin sections, freeze-cleaving, negative contrasting, optical diffraction of electron microscopic images), low-angle X-ray diffraction and biochemical methods. Some aspects of structural organization of specialized junctions providing for their functioning are concerned. Among other things, recent findings on the molecular structure of connexons and on their conformational changes promoting permeability regulation of their hydrophilic channels are reviewed. Available data on the lability of specialized junctions, both in the process of the organism's viability and during pathological states and after certain experimental treatment, are emphasized. Facts testifying to the lability of separate components of a junction including its perimembraneous cytoplasmic regions, are in a good agreement with a widespread liquid-mosaic model of the structural organization of cell membranes.