Showing papers by "Loma Linda University published in 1978"
TL;DR: It appears that the relative success of the citric acid application in periodontal reattachment procedures is realted to the fact that the acid causes exposure of collagen fibrils in the dentin matrix, thus providing a suitable nidus for splicing with new fibril during the healing process.
Abstract: The effect of topically applied citric acid on periodontally diseased root surfaces was evaluated using the scanning (SEM) and transmission (TEM) electron microscopes. Results with the SEM indicate that acid application had no effect on specimens that had not been root planed. After application to root planed surfaces, however, the acid priduced a fiber-like surface with frequent depressions. TEM observations showed that the acid application produced a four micron wide demineralized zone, which was characterized by exposed collagen fibrils. These fibrils seemed to be continuous between the mineralized and demineralized zones of the root.
It appears that the relative success of the citric acid application in periodontal reattachment procedures is realted to the fact that the acid causes exposure of collagen fibrils in the dentin matrix, thus providing a suitable nidus for splicing with new fibrils during the healing process.
200 citations
TL;DR: Topical acid application seems to be the crucial therapeutic factor in achieving new attachment in the present model of through-and-through furcation pockets in beagles.
Abstract: Chronic periodontal disease was induced and through-and-through furcation pockets created in mandibular premolars in two groups of beagles consisting of five and six animals respectively. The furcation defects were treated by surgical debridement supplemented with citric acid conditioning of the instrumented root surface. The relative importance of three adjunctive therapeutic measures was assessed. Thus, the effect of systemic antibiotics was evaluated by inter-group comparison. Gelfoam as a matrix support for the blood coagulum during healing was evaluated by intraindividual, contralateral comparisons in one group of animals. Coronal repositioning of the muco-periosteal flaps was evaluated by contralateral comparisons in the second group of animals. Block specimens for histological evaluation were removed six weeks after surgery. A high rate of regeneration and new attachment of the furcations was obtained irrespective of the use of systemic antibiotics, Gelfoam and high or low flap positioning. Thus, topical acid application seems to be the crucial therapeutic factor in achieving new attachment in the present model of through-and-through furcation pockets.
181 citations
TL;DR: The results indicate that the fetus in utero is affected by relatively low CO concentrations in the maternal environment.
Abstract: We investigated the effects on fetal growth and development of continuous exposure of pregnant rats to low level carbon monoxide (30 or 90 ppM CO) and a low oxygen atmosphere (13% O/sub 2/). While neither CO concentration induced a hematologic response in the pregnant animals, 13% O/sub 2/ exposure elicited an increase in hematocrit, the number of erythrocytes and hemoglobin concentration. Fetal body growth was unaffected by either CO concentration; however, it was reduced significantly in fetuses exposed to 13% O/sub 2/. The individual organ weights were differentially affected by 90 ppM CO. The fetal brain wet weight increased 14%, whereas the lung weight decreased 24%. We attribute the brain enlargement in the 90 ppM CO fetuses to an increased water content as evidenced by decreased concentrations of brain protein, DNA, norepinephrine and serotonin and a reduced dry-wet weight ratio. The results indicate that the fetus in utero is affected by relatively low CO concentrations in the maternal environment.
85 citations
TL;DR: The absolute poststimulation cortisol levels provided better separation of control subjects from patients with adrenal or pituitary insufficiency than either the increment in cortisol levels or the 11-deoxycortisol response to metyrapone.
74 citations
TL;DR: Extrusion in a vertical direction was used in efforts to retain 14 teeth that had subcrestal fractures, perforations, or caries below the gingival tissue.
Abstract: Extrusion in a vertical direction was used successfully in efforts to restore teeth that had subcrestal fractures, perforations, or caries below the gingival tissue. Extrusion in a vertical direction was used in efforts to retain 14 teeth that had subcrestal fractures, perforations, or caries below the gingival tissue. Indications for the procedure, techniques, and complications are discussed.
72 citations
TL;DR: It appears that antigen-antibody complexes and IgE-mediated reactions can initiate preliminary changes in periapical tissues and it is likely that delayed hypersensitivity participates in the perpetuation and progression of periAPical disease.
58 citations
TL;DR: A method of tissue embedding using n-butyl methacrylate and paraffin and a water trough attached to the microtome knife is essential to facilitate the handling of sections and ribbons.
Abstract: A method of tissue embedding using n-butyl methacrylate and paraffin is described. Following alcohol dehydration and infiltration with the methacrylate monomer, tissues are embedded in gelatin capsules in a mixture consisting of 3.5 g of paraffin for each 10 ml of methacrylate. Benzoyl peroxide (0.2 g for each 10 ml of monomer) is added as the catalyst and the methacrylate polymerized in a 50 C oven for 18-24 h. Following polymerization the block is trimmed and embedded in paraffin to provide a firm support during sectioning. A water trough attached to the microtome knife is essential to facilitate the handling of sections and ribbons. For serial sections a mixture of equal weights of beeswax and paraffin is used to make the sections adhere to each other. Usual staining procedures can be used since the embedding medium is readily soluble in xylene.
23 citations
TL;DR: It is suggested that persons who discover or witness a suicide may represent a sub-population of survivor-victims who need special postventive care and a call is made for research to investigate this further.
Abstract: At least 25,000 suicides are identified each year. For each suicide there are approximately six survivor-victims left bereaved (Shneidman, 1969). The present study examined 1,092 suicides committed...
16 citations
01 Jan 1978
16 citations
01 Jan 1978
TL;DR: The aspiration of red cell membrane into small holes is a technique that has been widely used to measure membrane elastic moduli and is described in detail in this paper.
Abstract: The aspiration of red cell membrane into small holes is a technique that has been widely used to measure membrane elastic moduli.
14 citations
01 Jan 1978
TL;DR: A recently published mathematical analysis allows the precise determination of the forces which acting on the red cell membrane cause any red cell to assume a particular shape, however, the effective use in the study of membrane physiology and pathology is dependent on the availability of large numbers of accurately measured RBC cross sections.
Abstract: A recently published mathematical analysis allows the precise determination of the forces which acting on the red cell membrane cause any red cell to assume a particular shape. The effective use of this analysis in the study of membrane physiology and pathology, however, is dependent on the availability of large numbers of accurately measured RBC cross sections. Red cells under study must be suspended in physiologic solutions; this effectively limits the data gathering technique to light microscopy. The low resolving power of the light microscope causes a diffraction band to overlie the membrane and renders the determination of the actual membrane location difficult. This problem was first examined by Ponder in 1930, when he formulated a technique that has come to be known as ‘Ponder’s Rule’.
TL;DR: The authors used a behavioral approach in which plastic shapes represented words of varying degrees of abstractness to teach eight nonverbal retarded subjects to communicate using a technique developed by Premack, which was a four-month training period and six of the eight subjects learned to construct three to seven-word sentences.
Abstract: Eight nonverbal retarded subjects were taught to communicate utilizing a technique developed by Premack. The subjects were moderately to pro-foundly retarded and had not responded to other forms of remedial language therapy. The technique used was a behavioral approach in which plastic shapes represented words of varying degrees of abstractness. All eight subjects learned some words within a four-month training period. Six of the eight subjects learned to construct three-to seven-word sentences. The rate of learning and level of difficulty attained varied greatly, and was not correlated with MA or CA. Children in a normal nursery school comparison group learned all words and constructed three-to seven-word sentences within a three-week period.
TL;DR: The author uses a somatic classification for sex among these patients, similar to the classification he uses for the neurogenic bladder and bowel, which indicates the ability to have orgasms among the females is dependent on the status of sensation present in the clitoris, labia, and nipples.
Abstract: The author uses a somatic classification for sex among these patients. It is similar to the classification he uses for the neurogenic bladder and bowel. Four categories are used: Reflex Complete Sex, Reflex Incomplete Sex, Areflexic Complete Sex, and Areflexic Incomplete Sex.
TL;DR: The venom apparatus of Lapemis hardwicki, consisting of two functional fangs, their venom glands, and associated musculature, are described and the toxicological, chemical and immunological properties of the venom are discussed.
TL;DR: Phospholipid analysis of kidney lipids from active and hibernating ground squirrels (Citellus lateralis) indicate that molar quantities of phosphatidyl choline increase, while sphingomyelin decreases in hibernated animals.
Abstract: 1. 1. Phospholipid analysis of kidney lipids from active and hibernating ground squirrels ( Citellus lateralis ) indicate that molar quantities of phosphatidyl choline increase, while sphingomyelin decreases in hibernating animals. 2. 2. Both of these changes are in such a direction as to enhance membrane fluidity and possibly contribute to low-temperature membrane function in these organisms.
01 Jan 1978
TL;DR: Two techniques for measuring the deformability of the red blood cell membrane give divergent results and indicate that an exponential stiffening occurs with increasing deformation, a response highly characteristic of most biological materials.
Abstract: Two techniques for measuring the deformability of the red blood cell membrane give divergent results. The folded cell traction technique indicates that an exponential stiffening occurs with increasing deformation, a response highly characteristic of most biological materials. Up till now, when membrane has been analyzed by the micropipette aspiration technique, no change in membrane characteristics has been elicited even at large deformations.
TL;DR: The ring, developed at the University of Florida, not only supports the globe but also obviates the need for any additional means of eyelid separation, which eliminates the problem of excessive speculum bulk or weight which sometimes leads to cum bersome maneuvering or increased pressure on the globe.
TL;DR: In this paper, a power spectral analysis of the cortical electrical activity was performed to obtain a measure of functional brain metabolism, and the authors used cats anesthetized similarly to humans undergoing microanastomosis surgery.
Abstract: In the course of an investigation of adding new collateral blood flow to the cortex of ischemic patients, the point was raised as to whether an increase in cortical oxygen tension would lead to improved oxygen utilization and energy production. If so, this might at least partially supply an explanation for improved neurologic function. The work on isolated mitochondria is firm in stating that there is no decrease in O2 utilization until less than 0.1 mmHg ambient PO2 (Chance et al, 1955, 1973). On the other hand, recent work on in vivo mitochondria suggest that they may respond differently, i.e., changes in cortical mitochondrial respiration may occur at a much higher brain PO2 (Rosenthal et al, 1975 & Austin et al, 1975). To investigate this problem, the authors used cats anesthetized similarly to humans undergoing microanastomosis surgery. Previous reported studies by others had shown the cytochrome a3 end of the respiratory chain to be more responsive to changes in O2 concentration. In the present study, the authors have added measurements of relative cortical PO2 (bPO2), relative cortical O2 utilization (bṖO2), and a power spectral analysis of the cortical electrical activity to obtain a measure of functional brain metabolism.
01 Jan 1978
TL;DR: Abdominal scanning provides a challenge for ultrasonography; however, much of these problems can be overcome by high resolution real time scanning.
Abstract: Abdominal scanning provides a challenge for ultrasonography. Bowel gas and ribs often interfere with the resultant image. Much of these problems can be overcome by high resolution real time scanning.
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01 Jan 1978
TL;DR: The body’s need for each nutrient, the effect on health of a deficiency or an excess, and the quantitative interrelationships of nutrients are studied.
Abstract: Throughout the history of the nutritional science, attention has centered mainly on the nutrient requirements. Fats, proteins, carbohydrates, minerals, vitamins and the water intake have all come under close study in an effort to determine the body’s need for each, the effect on health of a deficiency or an excess, and the quantitative interrelationships of nutrients.
TL;DR: It is concluded that the brief elevation of T4 and T3 after bTSH stimulation exerts a suppressive effect on the pituitaries which extends beyond the period of elevated thyroid hormone levels, and that delay in pituitary recovery is the mechanism of the decreased thyroid function after acute b TSH stimulation.
Abstract: The course of serum T4 and T3, return to baseline after TSH stimulation was studied in two groups at six normal subjects over 28 days after im bovine TSH (bTSH; 0.15 U/kg). In the first group of six subjects, serum bTSH rose from undetectable levels to a mean peak of 5.6 ± 0.5 ng/ml (mean ± SE) at 2 h, and fell below detectable levels by 24 h with a tfrac12 of 7 ± 1 h. T4 rose to a peak 59 ± 10% above basal levels within 24 h, returned to basal levels on day 7, then dropped below basal levels on days 9–24, with a nadir of −16 ± 4% on day 14. Free T4 paralleled T4 levels. T3 rose to a peak 104 ± 28% above basal at 24 h, then fell faster than T4, reaching basal levels by day 4. During the period of low T4, T3 was at or below basal levels. Human TSH (hTSH) concentration dropped when T4 and T3 rose, but did not rise above basal levels when T4 and T3) fell below basal levels. Neither a T3) elevation nor an increased percentage of free T4 was present during the time of reduced T4 levels. The same pattern of thy...
TL;DR: Measurements of the rate of pH changes in blood were not made until recently, but they were found to be less than the difference observed between arterial and venous blood samples.
Abstract: About 50 years ago Henriques1 calculated the rate of dehydration of bicarbonate to CO2 in the lung capillaries He showed that the uncatalyzed reaction is too slow to allow sufficient transfer of CO2 during the short time the blood spends in the capillaries This stimulated the search for an enzyme which catalyzes the reaction, and in 1933 Meldrum and Roughton2 and Stadie and O’Brien3 reported the presence of such an enzyme, carbonic anhydrase, in red cells In 1935 Roughton4 suggested that because carbonic anhydrase is absent in plasma, the rate of pH changes in plasma must be slow, and that pH changes in circulating blood would be less than the difference observed between arterial and venous blood samples Surprisingly, however, actual measurements of the rate of pH changes in blood were not made until recently5, 6, 7
01 Jan 1978
TL;DR: In this paper, the authors refer to three or four of the methods that Dr. Chien mentioned and extrapolate from those methods certain items of information which they think are relevant to the way the red cell membrane molecules are put together.
Abstract: I would like to refer to three or four of the methods that Dr. Chien mentioned and I am going to extrapolate from those methods certain items of information which I think are relevant to the way the red cell membrane molecules are put together. Due to time constraints this will be a very arbitrary process; I won’t discuss those observations I don’t think are germane and I will omit others I don’t know how to fit in.
TL;DR: The method described in this article involves the use of the acid-etch concept, composite resin, and interlocking TMS Minim pinst in the lingual embrasure and might be classified as semipermanent.
Abstract: Splinting of teeth follows a pattern of either a temporary type of splint or a permanent type of splint. The classic temporary splint is composed of wires which circumferentially engage the six lower incisors and impart a degree of rigidity and support to them, especially when the wires are stabilized with one of the unfilled resins.' These techniques often rely upon surface anchorage to enamel via the acid-etch method. The major disadvantage of this method is danger of fracture at the composite-enamel junction. Effective permanent splinting of lower anterior teeth may be accomplished by crowning the teeth or by anchoring them to a lingual plate of gold with pins. These pins may be an integral part of a gold casting,2. 3 or they may be screwed to the lingual gold plate.4. 5 To ensure permanence they are cemented to the teeth to convert them into a single rigid unit. The major disadvantages of the pin-retained casting are its expense and difficulty in fabrication. The method described in this article might b e classified as semipermanent. It involves the use of the acid-etch concept, composite resin, and interlocking TMS Minim pinst in the lingual embrasure (Fig. 1).