Research Methods in Life Sciences Commons^™

Histology Of Apical Tissue : A Comparative Study Of Sargenti Formula, Short Vs. Overfill, James G. Schulze

Loma Linda University Electronic Theses, Dissertations & Projects

Four Stump-tail monkeys (Macaca spiciosa) were used for this study to analyze, on a cellular level, the apical tissue of teeth overfilled versus teeth filled short 1-3 mm. of the radiographic apex with the Sargenti formula. In each animal four incisors were filled short and four incisors were overfilled. A final sample size consisted of 28 teeth. The time periods ranged from 48 hours to 120 days. After analysis of the histology it can be stated that the teeth filled short showed no inflammation to moderate inflammation in the periapical tissues. In teeth overfilled there was a range from moderate …

Determination Of Lead Content In Apical Tissue Following Root Canal Obturation With Sargenti's Formula, G. Merle Hickok

Loma Linda University Electronic Theses, Dissertations & Projects

Four Stump-tail monkeys were used to help determine if the lead in Sargenti's formula diffuses out into the apical tissue while confined entirely within the root canal. In each animal two teeth were filled with Sargenti's formula 1-2 millimeters short of the radiographic apex, and two teeth were filled with gutta percha and Proco-Sol sealer for controls, making a total sample size of sixteen. The time ranged from 48 hours to 120 days. Lead analysis using the spectrophotometric method showed a higher lead content in the teeth filled with Sargenti's formula than with the gutta percha controls.

The Effect Of Insulin, Fluoride And Methyl Xanthines On The Hypothalamic-Parotid Gland Endocrine Axis, Reagan Ondler

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the effect of insulin and fluoride on dentinal fluid movement (FM) in high-sucrose fed rats as mediated through the hypothalamic-parotid gland endocrine axis. In conjunction with the fluoride study, the possible involvement of cAMP was examined through the use of several methyl xanthines which are recognized as phosphodiesterase inhibitors.

Twenty-one day old, male Sprague Dawley rats were maintained on a high-sugar diet (62% sucrose) for 8-9 days at which time intravenous or arterial infusions of insulin, fluoride or the methyl xanthines were performed. Additional procedures included collecting plasma from rats which had …

Factors Relating To Diapause In The Alfalfa Weevil Parasite Bathyplectes Curculionis (Thomson), David S. Parrish

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Biological and ecological factors regulating diapause in the ichneumonid parasite of the alfalfa weevil, Bathyplectes curculionis (Thomson), were studied. In most experiments, both parasites and weevil larvae were maintained in the environmental conditions under study from the emergence of the adult parasite until the evaluation of results.

The factors either preventing or inducing diapause in B. curculionis were found to be an interaction of environmental factors. A long scotophase with cool temperatures prevented diapause. The percentage of nondiapausing parasites increased as the scotophase was increased to 15 hours. Over 15 hours of scotophase, fewer nondiapausing parasites were produced. The optimum …

The Relationship Of Alcohol Consumption In Rats To Morphine And Codeine Intake And The Metabolism Of Dopamine, Hsiu Fen Liu

Loma Linda University Electronic Theses, Dissertations & Projects

The effects of morphine and codeine free-choice alcohol consumption in male Sprague-Dawley rats were studied. Intakes of a 10% alcohol solution in milliliters per 100 gm. of body weight were on recorded weekly. No difference was found in the alcohol intake of rats given either a morphine-supplemented diet (0.01% of the diet) or daily injection of morphine sulfate (2 mg./kg.); however, there was a significant lower intake of water (p < .05) in those rats fed the diet with morphine. Total fluid consumption of both groups given the morphine-supplemented diet and daily injection of morphine sulfate was decreased (p < .05). It was found that morphine did not affect the percentage of total fluid consumed as alcohol or the weight gain.

Two levels of codeine phosphate (10 mg./kg. and 20 mg./kg.) were injected subcutaneously into rats twice a day. It was observed that the codeine significantly decreased alcohol intake in rats …

Concurrent Infections Of Trypanosoma Equiperdum And Trichinella Spiralis In Mice, Pauline A. Nembhard

Loma Linda University Electronic Theses, Dissertations & Projects

In concurrent infections of Trichinella spiralis and Trypanosoma equiperdum, the survival times vary in the early stages of the Trichinella infection. On Days 1 and 4, the mean survival times are significantly increased, and on Days 3 and 7 they are markedly decreased. This decrease is probably due to intestinal tissue invasion. Mice infected with trypanosomes after the 7th day of the Trichinella infection have survival time increases to a significant point and a steady leveling off to Day 21. It is suggested that the antibodies produced against the Trichinella worms slow down multiplication of trypanosomes and increase the …

Bone Regeneration Over Submerged Dental Roots In Dogs, Roger Lee Plata

Loma Linda University Electronic Theses, Dissertations & Projects

Nonendodontically treated roots were submerged 1.5 to 2.0 mm. below the alveolar crest in three dogs. Twelve roots were treated in this manner. Regeneration of alveolar bone can be seen in three weeks with complete bone coverage in five weeks. A complete lamina dura can be seen around the amputated roots.

Bone failed to regenerate over two of the twelve roots. In one case there was delayed healing due to the early loss of some sutures. A sinus tract developed connecting the oral environment with the contents of the pulp. This led to bone resorption and a necrotic pulp. In …

The Developmental Fine Structure Of Pacinian Corpuscles, Pedro B. Nava

Loma Linda University Electronic Theses, Dissertations & Projects

A preliminary light microscopic study of the mouse hind limb revealed a group of about 20 Pacinian corpuscles extending from the mid-region of the fibula to the tibio-fibular fusion strategically located for the possible sensing of bone-transmitted vibration.

The fine structure of the corpuscles is described in four stages: primordial or prenatal (19 and 20 days); early differentiation (1-8 days postnatal); differentiated corpuscle (9, 10, 12, 14 and 21 days postnatal); and adult (28 days old).

The corpuscles commence development during the 19th prenatal day. The corpuscle then consists of a nerve ending surrounded by sheath-cells which appear to be …

Histologic Comparison Of Apical Tissue Response To Endodontic Overfills With Gutta Percha And Grossman's Sealer Vs. Sargenti Method (N₂), Donald L. Brewer

Loma Linda University Electronic Theses, Dissertations & Projects

This study compared endodontic overfills of N₂ and gutta percha-Grossman's Sealer from a histopathological basis. The study employed four male rhesus monkeys and a sample of 31 teeth.

The most obvious difference between the samples filled with N₂ and the gutta percha-Grossman's Sealer samples was the recurring presence of ankylosis in the N₂-treated teeth. Results also included bone necrosis, inflammation and root and bone resorption.

The N₂ samples were considered to have evidenced greater violence of reaction apically.

Effects Of Cocaine, Nicotine And Diet On Voluntary Alcohol Consumption In Rats, Zaida Raquel Cordero Loayza

Loma Linda University Electronic Theses, Dissertations & Projects

The consumption of alcohol is a problem not only in this country (U.S.), but also in many other places in the world. Thus we find the Indians in Peru, Bolivia and other neighboring countries (Ecuador and northern part of Argentina) consuming alcohol to the point that they become alcoholics, in addition to this they also chew coca leaves, plant from which cocaine is extracted.

In an effort to establish the cause for this behavior, we put Sprague-Dawley albino rats on either a poor or good basal diet. Once every other day the rats were injected with a solution of cocaine. …

The Medina Pig Research Station, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Before the Department of Agriculture's Medina Pig Research Station was established in 1964, pig production research had been carried out on Denmark Research Station, Muresk Agricultural College and in some commercial herds.

However, with increasing specialisation in the pig industry better facilities were needed. Medina Research Station provides such facilities, allowing it to carry out research to provide detailed information of immediate practical value for both extensive and intensive pig production enterprises.

Viability Of Dentin In Rats Incisors : Fluid Movement In Pulpless, Endodontically Treated, And Normal Teeth In Rats, Maria Luisa Canales

Loma Linda University Electronic Theses, Dissertations & Projects

It is a well established fact that there is a fluid transport system through the dentin, however to the present time very little has been done regarding this system in teeth that have been endodontically treated.

The present work was conducted in vivo using the lower incisors of rats as the medium for the study.

A selected number of Sprague Dawley rats (36 animals), whose average age was 60 days, and whose body weight averaged about 180 grams, were given an anesthetic of Sodium Pentabarbitol, .05 to .07 ml. per 100 grams body weight. This anesthetic was injected intraperitoneally.

The …

The Effect Of Post-Operative Use Of Chlorhexidine On Periodontal Regeneration In Monkeys With Chronic Bifurcation Defects, J. Pat Bishop

Loma Linda University Electronic Theses, Dissertations & Projects

Periodontal regeneration and inflammation was evaluated histometrically in 36 paired teeth in six macque(sic) monkeys with chronic bifurcation defects. Daily topical TL Chlorhexidine was applied to one-half of the teeth, saline to the other half for six weeks after the bifurcation defects were surgically debrided. Measurements were made from a section taken from the mid-bifurcation for each tooth. The results demonstrated no significant difference in the area of inflammatory response or the degree of regenerative capacity of post-operative healing between Chlorhexidine treated and paired nontreated control teeth.

Effect Of Post-Operative Use Of Chlorhexidine On Regeneration Of Bifurcation Defects In Dogs, Gary Bogle

Loma Linda University Electronic Theses, Dissertations & Projects

The daily post-operative use of topical chlorhexidine application has been compared to daily toothbrushing. Periodontal defects were experimentally created in the bifurcations of lower premolars in dogs. The defects were treated by surgical debridement. Chlorhexidine application and toothbrushing were performed post-operatively for six weeks on contralateral pairs of teeth. The amounts of connective tissue and bone regeneration were evaluated from microscopic sections of the bifurcation areas. No difference between chlorhexidine and tooth brushing was found for the connective tissue attachment. However, significantly more bone had regenerated in the chlorhexidine treated areas than the tooth brushed area.

Effects Of Hypothyroidism In Mice Infected With Schistosoma Japonicum Katsurada, 1904, Venus Ee-Siriporn

Loma Linda University Electronic Theses, Dissertations & Projects

Section I:

In order to determine the effects of propylthiouracil-induced hypothyroidism on the Formosan strain of Schistosoma japonicum in mice, one group of mice (NON-PTU) was maintained on Purina Lab Chow meal only; the other group of mice (PTU) was fed a goiterogenic diet of 0.2% propylthiouracil in Purina Lab Chow meal. The mice in both groups were percutaneously exposed to 60 to 72 cercariae. The mice were perfused for schistosomes after an infection period of two months. It was found that the number of worms recovered was not significantly different between the two groups of mice. PTU mice weighed …

The Effects Of Crowding On The Diurnal Ascorbic Acid Levels Of Albino Rats, Mary Jo Barr

Masters Theses

The adrenal physiology of the albino rat was studied through the measurement of adrenal ascorbic acid levels. A cyclic phenomenon was observed which follows the diel periodicity of the animal. Ascorbic acid values were found to be characteristically higher in males than in females. A similar difference was also seen in populations divided into young animals (body weight less than 175 grams) and old animals (body weight greater than 175 grams). Crowding, induced by manipulating the area of cage space per gram of body weight, was observed to be a definite stressor and caused the adrenal ascorbic acid levels to …

The Effects Of Acute Stress On Adrenal Ascorbic Acid Levels, Robert Joseph Collier

Masters Theses

The diurnal rhythm of adrenal ascorbic acid (DAR) displays an inverse relationship to the diurnal rhythm of circulating levels of plasma corticosteroids. Alloxan monohydrate, 175 mg/kg body weight was given subcutaneously to albino rats to determine the effect of the diabetic state on the DAR. A total of 200 female albino rats were divided into two study groups. Study Group I was composed of 150 animals divided into populations of 15, each including 3 controls. Study Group II was composed of populations of 5, each group containing all controls or all alloxinated rats. The populations of 15 were sacrificed at …

Effects Of Dietary Factors And Morphine Administration On Voluntary Alcohol Consumption And Dopamine Metabolism In Rats, Claudia Smithson

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of diet and dietary additives on voluntary alcohol consumption in male Sprague-Dawley rats was studied. Alcohol intake measured weekly and reported as ml of a 10% solution ingested per 100 grams body weight. A four week pre-experimental period was designed to determine individual tendencies to drink and thus to eliminate the high and low drinkers from the study. No difference was found in alcohol intake with either starch or sugar as the carbohydrate source; however, there was a greater weight gain ( p < .025) in those animals consuming sugar-based diets. Rats on poor-quality diets containing minimal amounts of vitamins and minerals continued to gradually increase alcohol consumption during the study. This diet, supplemented with coffee, caused the greatest significant increase in alcohol intake and the lowest weight gains. Addition of coffee to the diets significantly increased alcohol consumption (p< .005) but decreased growth rate (p < .0005) . However, when the poor quality diets were supplemented with vitamins and minerals, alcohol consumption was reduced by about 50% (p < .005) and weight gain was significantly increased (p < .0005).

The daily intraperitoneal administration of morphine sulfate significantly decreased alcohol intake (p < .02) and the per cent of total fluid consumed as alcohol (p < .02) but did not effect water consumption.

An attempt was …

The Germfree Culture Of Three Species Of Triatominae: Triatoma Protracta (Uhler), Triatoma Rubida (Uhler), And Rhodnius Prolixus Stål, Stephen A. Nyirady

Loma Linda University Electronic Theses, Dissertations & Projects

Triatoma protracta protracta, Triatoma riibida rubIda, and two strains of Rhodnius prolixus were successfully reared germfree into the fourth generation. Triatominae eggs were disinfected externally with iodine and the nymphs reared in vinyl plastic germfree modules. Germfree mice were used as the host. This is the first report of Triatominae having been reared in a germfree environment. These bugs were never exposed to bacteria internally or externally to the fourth generation.

Comparisons of conventional control bugs with replicate germfree groups in the first two generations revealed but slight differences in developmental periods. The mean adult longevity of all …

Microscopic Evaluation Of Topically Applied Chlorhexidine Gluconate On Gingival Wound Healing In Dogs, Robert C. Hirst

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate microscopically the effect of topically applied 2% chlorhexidine gluconate on the healing of gingival wounds in dogs.

One week after the teeth were scaled and polished, seven experimental wound sites were prepared in the facial gingiva adjacent to the four premolars on each side of the maxillary arch in six young Labrador dogs. From this point the dogs were fed a soft plaque-inducing diet. Chlorhexidine solution was applied daily to either the right or left maxillary premolars while on the opposite side of the arch in three dogs the first and second …

Marrow Isografts In The Oral Cavity Of Mice, Robert L. Merin

Loma Linda University Electronic Theses, Dissertations & Projects

The objectives of this study were to develop an animal model for testing oral bone and marrow transplantation that is adaptable to immunological studies; to determine the effect of an isogeneic graft of cancellous bone and marrow on the healing of surgically created defects; and to determine the fate of grafted isogeneic cancellous bone and marrow transplanted into defects. Fourteen CBA/H mice served as experimental animals and bilateral intraoral defects were prepared. The experimental side received isogeneic graft material while the other side served as a control. Osseous healing was found to be accelerated in the defects receiving graft material …

The Effect Of Oral Allografts Of Cancellous Bone And Marrow In Mice, George E. Deeb

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was: to develop a model for testing oral bone transplantation; to study the healing of a surgically produced defect with and without the transplantation of strongly allogeneic cancellous bones and marrow; and to determine the fate of the allogenic grafts. Twenty-eight CBA/H mice served as experimental animals. Intra-oral defects were made and in 14 of the animals strongly allogenic cancellous bone and marrow were transplanted. The 14 remaining animals served as controls. It was observed that the healing was delayed in the experimental animals as compared to the controls and that the grafted material was …

State-Dependent Learning As A Function Of The Temporal Relationship Between Noncontingent Footshock And Electroconvulsive Shock, T. Scott Shutt

All Master's Theses

Rats were given a noncontingent footshock followed at various intervals by electroconvulsive shock. Twentyfour hours later they were trained on a non-shock passive avoidance task and tested for retention 72 hours later. When the interval between NCFS and ECS was short the animals showed an amnesia which reduced as the interval was lengthened. An interval of .5 seconds produced the most pronounced amnesia and intervals greater than 10 seconds produced virtually no amnesia. The results were consistent with a state dependent retrieval failure hypothesis.

Root Exposure And Its Effect On The Fluid Movement Within The Tooth, William J. Busch

Loma Linda University Electronic Theses, Dissertations & Projects

This study examined the fluid movement in dentin associated with the exposure of the root surface for varying periods of time ranging from 75 minutes to 30 days. Eight kittens received experimental defects on the roots of the canines. Just prior to sacrifice a fluorescing dye was injected intraperitoneally to make the fluid within the dentin visible under ultraviolet light. Frozen ground sections were prepared and examined. The results showed that the exposed side of the root had a reduced amount of fluid fluorescence when compared to the opposite side of the tooth which had an intact root surface. The …

The Cathartic Effects Of Aggressive Responses Directed Toward An Inanimate Object, Timothy William Creston

All Master's Theses

This study was intended to test the catharsis of aggression hypothesis which in part holds that aggressive responses directed towards an inanimate object will have a tension reducing effect and result in a lowering of residual hostility.

Cardioregulatory Role Of The Abdominal Ganglion Of Aplysia Californica, George Maeda

Loma Linda University Electronic Theses, Dissertations & Projects

An isolated heart-abdominal ganglion preparation of this mollusc was developed and used to study the cardioregulatory function of the ganglion and nerves. The heart was perfused with artificial sea water through an atrial cannula and the gastro-esophageal artery was catheterized for blood pressure monitoring. The presence and cardioregulatory effects of axons in the nerves was investigated by electrical stimulation. Fine-tipped glass microelectrodes inserted into ganglionic neurons were used to determine the relationship between the neuronal and cardiac activities.

The principal results are listed below.

1. Primarily inhibitory responses are obtained from both right and left connective stimulation, with some evidence for …

Sub-Aversive Response Contingent Foot Shock As A Positive Reinforcer, Robert Lea Fulwiler

All Master's Theses

Forty-eight rats were divided into 8 groups; four were maintained under normal conditions and the other four under sensory deprivation and tested at o, 3, 6, and 9 days after condition institution. The response was placing the head through a hole in the operant chamber and the stimulus (0, 1.2, 4, or 12 Vac) was contingent upon the response. Analysis ot variance disclosed significant differences (p<.01) between the deprived and the non-deprived groups at days 6 and 9; and a significant interaction between deprivation condition and time of test. No differences were shown between the stimulus intensities indicating that the stimulus did not have a reinforcing effect.

The Effect Of Elevated Glucose On Neutrophilic Phagocytosis In Genetically Diabetic Mice, Larry B. Thompson

Loma Linda University Electronic Theses, Dissertations & Projects

Infiltration to an injury site or area of bacterial contamination by polymorphonuclear leucocytes (or neutrophils) is an early and essential phase of the early inflammatory reaction. Their action on foreign matter is the most critical step taken by body defense mechanisms in the first 24 hours. Anything which interferes with that action, phagocytosis, greatly hampers early inflammation. This study was designed to see the effect of elevated glucose levels on neutrophil phagocytosis in a unique strain of genetically diabetic mice.

Twenty-two diabetic and twenty-four control female mice were used. Blood glucose determinations and total white counts were made on each …

The Response Of Gingival Tissues To Alterations In Ph, Robert C. Jann

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the histopathological and clinical changes that occurred when a continuous supply of exogenous acid or base, at varying pH, was delivered adjacent to the gingival crest of the monkey. A related goal was to develop a monkey model system which would deliver test solutions continuously and atraumatically, to the experimental gingival sites.

Two young adult female monkeys had a perfusion apparatus attached to certain maxillary teeth so that test solutions were deposited atraumatically to the marginal gingival tissues. During the experimental periods the animals were kept in primate restraining chairs and fed …

The Effects Of Cs Habituation And Duration Of The Directional Modification Of The Cardiac Response In The Guinea Pig (Cavia Procellus), Ray Charles Larson

All Master's Theses

The present experiment examined the effects of CS habituation and two different levels of CS duration (60 versus 6 sec) on the directional modification of the conditioned cardiac response in the guinea pig. The results indicated that the only reaction to the CS, regardless of prior habituation or CS duration, was a decelerative conditioned HR response. However, habituation to a CS prior to classical aversive conditioning was found to attenuate the magnitude of the bradycardia CR that developed. The bradycardia CR was discussed in terms of being a cardiac component of the orienting response.