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Articles 481 - 510 of 513

Full-Text Articles in Research Methods in Life Sciences

The Effect Of Elevated Glucose On Neutrophilic Phagocytosis In Genetically Diabetic Mice, Larry B. Thompson May 1971

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 May 1971

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 May 1971

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.


Infectivity And Development Of Trichinella Spiralis In Germ-Free, Monocontaminated And Conventional Mice, Daulat Sitanggang Aug 1970

Infectivity And Development Of Trichinella Spiralis In Germ-Free, Monocontaminated And Conventional Mice, Daulat Sitanggang

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of the experiment was to compare the development of Trichinella spiralis in germ-free, Lactobacillus casei monocontaminated, Escherichia coli monocontaminated and conventional mice. The criteria used in the experiments were the recovery of adults and larvae of T. spiralis after 72 hours and one month post-infection, respectively. which gave an indication of the effects of no bacteria or only a certain, single species of bacterium on the development of this nematode in mice.

Germ-free T. spiralis larvae were obtained by washing them several times with sterile normal saline, and treatment with antibiotics. The gavaging procedure was done without anesthetization …


An In Vivo Perfusion Apparatus For Studies On Gingival Disease In The Albino Rat : Assessment By A Perfusion Of The Enzymes Collagenase And Hyaluronidase, James A. Smith Jun 1970

An In Vivo Perfusion Apparatus For Studies On Gingival Disease In The Albino Rat : Assessment By A Perfusion Of The Enzymes Collagenase And Hyaluronidase, James A. Smith

Loma Linda University Electronic Theses, Dissertations & Projects

This thesis describes an in vivo perfusion apparatus which can continuously deliver controlled quantities of solutions to localized, contralateral intraoral areas in albino rats. Three animals were per fused on the experimental area (the mesial sulcular area of the maxillary first molar) on one side with tap water and Trypan blue. Localization of the solution delivered and minimal histological changes due to the presence of the apparatus was demonstrated on these animals. Solutions of .5%, 1%, and 2% hyaluronidase and collagenase were perfused on the experimental areas of nine animals. When both enzymes were used, hyaluronidase always preceded collagenase in …


A Study To Demonstrate The Immediate Destination Of An Embolus Formed In The Lumen Of A Peripheral Venous Catheter, Rosemarie Morikone Emori May 1970

A Study To Demonstrate The Immediate Destination Of An Embolus Formed In The Lumen Of A Peripheral Venous Catheter, Rosemarie Morikone Emori

Loma Linda University Electronic Theses, Dissertations & Projects

This study was designed to show the immediate destination of an embolus formed in the lumen of an intravenous catheter placed in a peripheral vessel. The hypothesis stated that clots injected into a peripheral vessel will lodge in the lungs. A subhypothesis was that the clot may lodge anywhere along the circulatory pathway.

Indications of need for the study as shown by the review of literature were the following: (1) the complications resulting from the frequent use of intravenous polyethylene catheters, (2) experimental studies that showed that clots were formed around intravenous catheters, (3) the evidence that intravenous catheters predispose …


Effects Of Diet And Stress On Gastric Lesions In Albino Rats And Guinea Pigs, Naomi Mckenzie Jan 1970

Effects Of Diet And Stress On Gastric Lesions In Albino Rats And Guinea Pigs, Naomi Mckenzie

Loma Linda University Electronic Theses, Dissertations & Projects

Studies were conducted to (1) investigate whether any protective factor is present in fresh water-cured olives or fresh cabbage as compared with the heated supplements against stress-induced gastric lesions in rats maintained on a nutritionally adequate diet for six weeks, (2) determine the relative protective factor in water-cured olives as compared with cabbage, (3) study the effect of black pepper in combination with fresh cabbage and olives and heated cabbage and olives in rats that were fed the same nutritionally adequate diet, and (4) investigate the effects of the same dietary components—cabbage and olives--on histamine- induced gastric lesions in guinea …


Mandibular Nerve Regeneration Through Solid And Canalized Bone And Plaster Grafts, Lawrence D. Day Aug 1969

Mandibular Nerve Regeneration Through Solid And Canalized Bone And Plaster Grafts, Lawrence D. Day

Loma Linda University Electronic Theses, Dissertations & Projects

Utilizing an extra-oral approach and sterile technique, left mandibular ostectomy was performed on five miniature pigs. The segment removed was 3 cm long and included the inferior border, mandibular canal and, in some cases, apices of a molar tooth.

Bone and plaster grafts (one solid and one canalized of each) were used to fill these defects. The fifth was left with no graft.

The objective was to learn the effect of each of these procedures on regeneration of the mandibular nerve across the defect. It was hypothesized that canals through the grafts would facilitate regeneration.

X-rays were taken periodically. The …


The Intestinal Flora Of Triatoma Protracta Protracta (Uhler) (Hemiptera: Reduviidae) Including New Bacterial Isolation Techniques, Stephen A. Nyirady Jun 1969

The Intestinal Flora Of Triatoma Protracta Protracta (Uhler) (Hemiptera: Reduviidae) Including New Bacterial Isolation Techniques, Stephen A. Nyirady

Loma Linda University Electronic Theses, Dissertations & Projects

A bacteriological procedure for the removal of the intestinal flora of Triatominae is described. Immersion of Triatoma protracta adults and fifth instar nymphs in 5% aqueous formaldehyde for three hours was sufficient to free the integument of these insects of viable bacteria without penetration into the alimentary tract.

Twenty-two adults and 17 fifth instar nymphs of Triatoma protracta protracta were collected from Neotoma lodges in southern California. Eleven of the 17 nymphs molted into adults in the laboratory. With the use of a 2% peracetic acid sterilized custom built plastic germ-free isolator the Triatoma were dissected and various sections of …


The Effect Of Removing The Crevicular Epithelium Upon Canine Tooth Replantation, Leon A. Leonard Jun 1969

The Effect Of Removing The Crevicular Epithelium Upon Canine Tooth Replantation, Leon A. Leonard

Loma Linda University Electronic Theses, Dissertations & Projects

The nature of epithelium and the remarkable facility with which it aggressively covers granulation tissue, suggests that removal of the sulcular epithelium surrounding the extraction wound of a tooth to be replanted could promote reattachment of the periodontal tissues at a more nearly ideal coronal level. To investigate this hypothesis twenty mature teeth in five mongrel dogs were experimentally replanted. One half of them were replanted in alveoli around which the crevicular epithelium had been removed, the remaining teeth without creviculoectomy acting as controls. Animals were euthanized at one, two, three, five, and sixteen weeks. After clinical evaluation of the …


A Cephalometric, Anatomic And Histologic Investigation Of The Effects Resulting From A Heavy Interrupted Orthopedic Force To The Maxilla Of The Macaca Mulatta Monkey, Roger Wayne Triftshauser Jun 1969

A Cephalometric, Anatomic And Histologic Investigation Of The Effects Resulting From A Heavy Interrupted Orthopedic Force To The Maxilla Of The Macaca Mulatta Monkey, Roger Wayne Triftshauser

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine changes that occur in the craniofacial complex, when a heavy interrupted orthopedic force is employed to retract the maxilla in the post puberal rhesus monkey. Cephalometric, histologic and anatomic examinations were utilized to substantiate the findings.

Four female rhesus monkeys were used for experimentation. Two were experimental animals and the other two controls. Cervical retraction with headgear was applied over a period of 313 days and 159 days to the two experimental animals. Forces not exceeding 2.5 lbs. were found most effective.

The findings were as follows:-

  1. A total posterior displacement of …


Some Aspects Of Cranial Bone Growth In The Puberal Macaca Mulatta Monkey: As Evidenced By Metallic Implants And Cephalometric Roentgenography And The Application Of A Geological Lapidary Technique For The Semi-Serial Thin Sectioning Of Undecalcified Bone, Lee Eugene Olsen Jun 1969

Some Aspects Of Cranial Bone Growth In The Puberal Macaca Mulatta Monkey: As Evidenced By Metallic Implants And Cephalometric Roentgenography And The Application Of A Geological Lapidary Technique For The Semi-Serial Thin Sectioning Of Undecalcified Bone, Lee Eugene Olsen

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to investigate cranial and facial bone growth in the puberal Macaca mulatta monkey over a six month period utilizing the methods of metallic implantation combined with serial cephalometric roentgenography and a bichromatic vital staining method.

The employment of the vital stains, alizarin Red S and anthracene blue, over the six month period of the study, failed to stain the actively growing bone as evidenced by gross and microscopic analysis of the undecalcified bone preparations.

Interimplant measurements were made across certain bone sutures and the following results were obtained: The zygomaticotemporal sutures showed marked growth …


The Transfer Of Hydrogen In The Reduction Of Progesterone, William H. Kersey Aug 1968

The Transfer Of Hydrogen In The Reduction Of Progesterone, William H. Kersey

Loma Linda University Electronic Theses, Dissertations & Projects

Experimental female rats were given daily injections of synthetic estrogens for six months. The effect on rat ovarian 20α-OH-SDH was not definitive. Diethylstilbestrol and 17α-ethynylestradiol caused a significant drop in activity as compared with controls while mestranol caused a slight increase in activity. A synthetic progestin, medroxyprogesterone, had no apparent effect on the activity of the enzyme.

Rat ovarian 20α-OH-SDH was purified fivefold by ammonium sulfate fractionation and chromatography on DEAE-cellulose.

The homogeneity of the enzyme was checked by means of disc gel electrophoresis. At pH 8.2 no significant contamination appeared in the electrophoretic pattern, but at pH 9.0 five …


Concurrent Infections Of Schistosoma Mansoni And Trypanosoma Equiperdum In Mice, Venus Ee-Siriporn Jun 1968

Concurrent Infections Of Schistosoma Mansoni And Trypanosoma Equiperdum In Mice, Venus Ee-Siriporn

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this investigation was to determine factors which may influence the survival time of mice infected with Trypanosoma equiperdum and the effects of T. equiperdum on mice infected with Schistosoma mansoni.

In order to maintain experimentally obtained standard hours of survival (88 hrs) in mice inoculated intraperitoneally with 150,000 T. equiperdum, it was found that trypanosomes removed from the donor rat should be kept at 25 C and all counts, dilutions of the organisms, and injection should be completed within 1 hour after removal from the donor host. Survival time of mice is increased as the …


Craniofacial Changes Resulting From Expansion Of The Midpalatal Suture In The Macaca Mulatta Monkey As Revealed By Roentgenographic Analysis, Raymond M. Sugiyama Jun 1968

Craniofacial Changes Resulting From Expansion Of The Midpalatal Suture In The Macaca Mulatta Monkey As Revealed By Roentgenographic Analysis, Raymond M. Sugiyama

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the effects of midpalatal suture separation on the craniofacial complex by quantitative roentgenographic analysis.

Ten female Macaca mulatta monkeys were randomly grouped for experimentation. Six animals were paired in groups for two months of treatment, four months of treatment followed by two months of post retention, and six months of treatment. The four remaining monkeys were paired and served as control animals for two and six month periods. Total activation of the expansion appliances in the treated animals was completed over a three week period.

The findings of this study were based …


Forced Separation And Consequent Stability Of The Midpalatal Suture Of The Macaca Mulatta Monkey, Frederick L. Hoffer Jr. Jun 1968

Forced Separation And Consequent Stability Of The Midpalatal Suture Of The Macaca Mulatta Monkey, Frederick L. Hoffer Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

This study was designed to (1) demonstrate the dimensional changes resulting from opening the suture, (2) test the stability of the repaired suture two months following the removal of the retentive appliance, and (3) demonstrate new bone growth in the opened suture by the use of Tetracycline staining. The animal chosen was the Macaca mulatta monkey.

Intact skulls, sectioned skulls and dental casts were measured following the experiment. The skulls were mounted in clear plastic and sectioned antero-posteriorly for the purposes of study and measurements. The following changes were noted as a result of this experiment:

  1. The floor of the …


Oral Bandage Tissue Reaction In Dogs, John Rozema Jun 1968

Oral Bandage Tissue Reaction In Dogs, John Rozema

Loma Linda University Electronic Theses, Dissertations & Projects

This experiment was designed to evaluate an oral surgical dressing which may be used as an aid to healing tissue. The parameters of evaluation were directed toward wound healing enhancement, duration, and stability of the bandage. A histological evaluation of the surgical wounds protected with the bandage as compared to the control wounds was made.

The surgeries were performed on eight dogs in a double controlled experiment and were in the form of bilateral maxillary gingivectomies and mandibular molar tooth extractions. The surgery sites on the left were covered with the Orahesive Bandage while the right side remained exposed to …


Effects Of Poor Quality Diets With Various Dietary Factors Added And Exposure To Cigarette Smoke On The Voluntary Alcohol Intakes Of Albino Rats, Bonnie Emmerson Jan 1968

Effects Of Poor Quality Diets With Various Dietary Factors Added And Exposure To Cigarette Smoke On The Voluntary Alcohol Intakes Of Albino Rats, Bonnie Emmerson

Loma Linda University Electronic Theses, Dissertations & Projects

Studies were conducted utilizing albino rats to determine the relationship of voluntary alcohol consumption with various dietary additives and exposure to cigarette smoke in combination with poor quality diets. Male, Sprague-Dawley rats, from weanling age to 100 grams, were given the various experimental diets and a free fluid choice of ten per cent ethanol or tap water. Fluid intakes were recorded and analyzed statistically. Individual variation was common with a generally low level of alcohol consumption when rats were fed a poor quality diet of common United States foods. The addition of caffeinated beverages and/or spices and relish caused increases …


Periosteal Circulation And Its Contribution To The Nutrition Of Compact Bone, Jean Elaine Tassell Aug 1967

Periosteal Circulation And Its Contribution To The Nutrition Of Compact Bone, Jean Elaine Tassell

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]


Carbon Dioxide Fixation In Schistosoma Mansoni, Clint Earl Carter Jun 1967

Carbon Dioxide Fixation In Schistosoma Mansoni, Clint Earl Carter

Loma Linda University Electronic Theses, Dissertations & Projects

Adults of the blood fluke Schistosoma mansoni were perfused from the hepatic portal system of CF1 female mice sixty to seventy days post infection. The worms were then incubated in Eagle’s minimal essential medium with glutamate and 0.03 mg/100 ml of nonlabelled aspartic acid. To this medium was added 10 μc of either NaH1403, glucose-UC14 or aspartate-4-C14. The worms were found to fix carbon from the NaH1403 and to incorporate the glucose and aspartate. The amount of activity recovered in five different chemical fractions after two hours incubation was determined …


Mandibular And Alveolar Growth In Dog Following Infusion Of 5-Fluorouricil, Richard D. Pfeiffer Jun 1967

Mandibular And Alveolar Growth In Dog Following Infusion Of 5-Fluorouricil, Richard D. Pfeiffer

Loma Linda University Electronic Theses, Dissertations & Projects

The action of a chemotherapeutic agent as a tool in studying its effect upon a primary growth center, the mandibular condyle, was investigated. So far as can be ascertained, no studies have been reported where these growth sites have been eliminated or modified by the use of chemotherapeutic growth inhibitors.

Observation of mandibular and alveolar growth following the infusion into the left external carotid artery of a cancer chemotherapeutic agent, 5-Fluorouricil (Roach-Hoffman), was noted. Comparisons were made between the infused and the uninfused sides of the mandible observing gross growth changes.

Four dogs, aged 75 days, were infused with varying …


The Effect Of Schistosoma Mansoni On Free Amino Acid Levels In Mice, Richard D. Tkachuck Jun 1967

The Effect Of Schistosoma Mansoni On Free Amino Acid Levels In Mice, Richard D. Tkachuck

Loma Linda University Electronic Theses, Dissertations & Projects

Free amino acid levels in the blood plasma of mice infected with Schistosoma mansoni Sambon, 1907, were measured at 3, 6, and 9 weeks post-infection with an automatic amino acid analyzer. Significant differences between experimental and control animals occurred at all three time periods. At 3 weeks, asparagine, alanine, citrulline, proline, methionine, and threonine levels all were lower in the infected animals. At 6 weeks, four differences were noted. Alpha-amino-n-butyric acid, ornithine, lysine, and histidine all had lower values in infected animals. At 9 weeks there were 12 differences. Tyrosine, phenylalanine, threonine, serine, proline, citrulline, glycine, alanine, valine, isoleucine, and …


The "Starvation Effect" And Tryptophan Pyrrolase Activity In The Vermilion Mutant Of Drosophila, Ernest E. Shelton Jr. May 1967

The "Starvation Effect" And Tryptophan Pyrrolase Activity In The Vermilion Mutant Of Drosophila, Ernest E. Shelton Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The enzyme tryptophan pyrrolase is controlled by the vermilion locus in Drosophila melanogaster and is normally lacking in the vermilion mutants. During this investigation it has been demonstrated that v1;bw flies have tryptophan pyrrolase activity when grown under near starvation conditions.

During development of the fly there is a peak of enzyme activity in the early third instar soon after the transfer to starvation medium. A second peak of enzyme activity occurs during the pupal stage. The activity in v1;bw pupae is about 15% of the activity found in cn bw adults.

In v …


The Fecal Shedding Of Listeria Monocytogenes By Conventional And "Germ Free" Mice, Margaret Joyce Ramsay Sep 1966

The Fecal Shedding Of Listeria Monocytogenes By Conventional And "Germ Free" Mice, Margaret Joyce Ramsay

Loma Linda University Electronic Theses, Dissertations & Projects

A series of experiments involving Listeria monocytogenes was undertaken to study first the fecal shedding of Listeria by conventional mice challenged intraperitoneally with Listeria and second the fecal shedding and ability to survive of germ free mice with similar challenge. In addition, mites infesting Listeria infected mice were cultured for their possible contamination by Listeria.

Conventional mice were challenged intraperitoneally with a single near LD50 dose of Listeria. Fecal Listeria were detected by collecting specimens from each mouse daily for the first 4 days and every second day thereafter. The feces was held at 7°C for 14 …


Antibiotics And The Wasting Disease In Neonatally Thymectomized Rats, Douglas M. Grignon Sep 1965

Antibiotics And The Wasting Disease In Neonatally Thymectomized Rats, Douglas M. Grignon

Loma Linda University Electronic Theses, Dissertations & Projects

The administration of the antibiotic, Chloramphenicol, to pregnant rats just prior to, and for four days after delivery, diminishes the incidence of the so-called "Wasting Disease" in neonatally thymectomized rats.

A total of 50 rats were divided into the following groups:

  1. Thymectomy only---nonmedicated 17 rats
  2. Thymectomy only---medicated 12 rats
  3. Thymectomy-adrenalectomy---nonmedicated 5 rats
  4. Thymectomy-adrenalectomy---medicated 8 rats
  5. Controls---nonmedicated 4 rats
  6. Controls---medicated 4 rats

Chloramphenicol was administered in the drinking water to the mothers of groups 2, 4 and 6 for about 2 days prior to delivery and 4 days after. On the day of birth or within three days after birth, the …


The Effect Of Varying Protein Intake On Trichinella Spiralis Infection In Mice, Clare K. Kwan Jun 1964

The Effect Of Varying Protein Intake On Trichinella Spiralis Infection In Mice, Clare K. Kwan

Loma Linda University Electronic Theses, Dissertations & Projects

Three hundred Swiss Webster albino mice three weeks of age were placed on low (8%), medium (24%), high (48%) protein levels and a commercial laboratory animal feed, Purina Chow for various lengths of time: (1) simultaneously with infection, and four weeks thereafter, (2) three weeks before infection and throughout the four-week infection period, and (3) six weeks prior to infection and during the infection period. The protein source was casein. Sixty of the 300 mice used served as noninfected controls, and the other 240 were each infected with 400 washed, suspended Trichinella spiralis larvae obtained from a rat by the …


A Study Of Regeneration Of Peripheral Nerve In The Rat, James C. Jay Jun 1962

A Study Of Regeneration Of Peripheral Nerve In The Rat, James C. Jay

Loma Linda University Electronic Theses, Dissertations & Projects

Due to improvements in fixation and embedding techniques a restudy of regenerating peripheral nerve was thought advisable in order to better understand and describe the processes which take place.

Femoral nerves of white Wistar rats were used. The lesions were made by either crushing or severing the nerve. After a period of regeneration, varying from 12 hours to six days, the wound was reopened and the injured portion fixed in situ with 1% osmium tetroxide. The tissues were then removed, dehydrated, embedded and sectioned. The sections were stained and studied with a modified RCA EMU2A electron microscope.

Observations revealed that …


Quantitative Evaluation Of Streptococcal Antibodies By A Serum Inhibition Fluorescent Antibody Tube Method, Charles Glenn Nichols Jun 1962

Quantitative Evaluation Of Streptococcal Antibodies By A Serum Inhibition Fluorescent Antibody Tube Method, Charles Glenn Nichols

Loma Linda University Electronic Theses, Dissertations & Projects

The development and description of a quantitative method of evaluating streptococcal antibodies by inhibition of fluorescent staining is reported. Suspensions of Streptococcus pyogenes group A, treated with methyl alcohol to reduce auto-fluorescence, were used as antigen. The degree of inhibition of uptake of fluorescent labeled antibody produced by the presence of antibodies in the immune test sera was measured after elution of the labeled antibody. Comparisons were made with controls using normal sera containing no inhibiting antibodies. A method of reporting the results in terms of titer is described.

Streptococcal antibodies were demonstrated quantitatively by this inhibition test in sera …


A Comparative Study Of The Growth Of Polyoma Virus In Two Secondary Cell Lines: Mouse Lymphoma And Normal Mouse Fibroblasts, Rheeta M. Stecker Jun 1961

A Comparative Study Of The Growth Of Polyoma Virus In Two Secondary Cell Lines: Mouse Lymphoma And Normal Mouse Fibroblasts, Rheeta M. Stecker

Loma Linda University Electronic Theses, Dissertations & Projects

In comparing the growth of polyoma virus in secondary cell cultures of a mouse lymphoma (P388D1, a known polyoma-supporting strain) and normal mouse fibroblasts (Earle’s L cells), the following observations have been made.

The L cell is capable of supporting the growth of the polyoma virus with reproduction and release of infectious particles. Viruses appear in the fluid from time to time over a period of several weeks. This probably represents a carrier state of the virus in L cells. Many of the L cells in infected cultures are not killed by the virus infection.

Virus particles released …


The Pacemaker Function Of The Small Intestine, Robert W. Hasselbrack May 1960

The Pacemaker Function Of The Small Intestine, Robert W. Hasselbrack

Loma Linda University Electronic Theses, Dissertations & Projects

New evidence is presented to clarify to some extent the significance of the gradient of rhythmicity in the small intestine of the unanesthetized dog. The gradient of rhythmicity was studied on five dogs prepared with duodenal fistulas. Rhythmic contractions were recorded from the small intestine by a small rubber balloon. The gradient of rhythmicity was found to decrease in a stepwise manner as the distance from the pylorus is increased. Roughly, the rhythmic contractions were found to be 18 to 19 per minute in the duodenum and 14 to 15 per minute in the ileum. In the terminal ileum there …