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Biomedical subjects

G Zimmerman

Publications and source records attributed to G Zimmerman.

At least 37 records · Page 2Linked to original sources
PubMed1993

Retention of antimicrobial activity by human root surfaces after in situ subgingival irrigation with tetracycline HCl or chlorhexidine.

Substantivity of tetracycline HCl and chlorhexidine digluconate was assessed in extracted teeth. Fifty periodontally compromised teeth scheduled for extraction with probing depths ranging between 6 and 12 mm were root planed and then irrigated in situ with 1 of 4 solutions: tetracycline HCl at concentrations of 10 or 50 mg/ml, 0.12% chlorhexidine digluconate, or 0.9% sterile saline. Each tooth was exposed to 150 ml of the respective irrigation solution. Following extractions, the teeth were transferred to tris buffered saline and incubated at room temperature for 22 days. Incubation solutions were replaced at 24-hour intervals. Removed solutions were examined for desorbed antimicrobial activity using a microtiter assay in which bacterial growth was evaluated by optical density readings. Tetracycline HCl 50 mg/ml exhibited significantly greater antimicrobial activity than chlorhexidine digluconate for 12 days and greater than saline for 16 days. Tetracycline HCl 10 mg/ml exhibited significantly greater antimicrobial activity than chlorhexidine digluconate and saline for 4 days. Chlorhexidine digluconate did not exhibit any significant antimicrobial activity at any time point. Our findings demonstrate long-lasting substantivity of tetracycline HCl, but not chlorhexidine digluconate, by teeth exposed to a single episode of pocket irrigation of their periodontally-exposed roots. The amount of antimicrobial activity retained is proportional to the concentration of tetracycline HCl used for irrigation.

Adsorption↗
PubMed1991

Isolation and continuous culture of Neorickettsia helminthoeca in a macrophage cell line.

Experimental evidence is presented supporting the development of a system for the isolation and propagation of a Neorickettsia sp. in a continuous canine macrophage cell line (DH82). To isolate a Neorickettsia sp. pathogenic to the canine species, three naive dogs were fed metacercaria-encysted kidneys of salmon caught in a river where infection of metacercariae with Neorickettsia helminthoeca has been circumstantially known for decades. Clinically, the classic course of salmon poisoning disease developed in all of the dogs. Parasitemia began on day 8 to 11 postinfection, when the dogs developed a febrile peak, and continued until euthanasia. At necropsy, characteristic gross and microscopic lesions of the disease were present. A Neorickettsia sp. was also isolated from liver and spleen samples of these animals. The isolates have been continuously propagated and passed in DH82 cells for more than 6 months. Electron microscopic examination confirmed that the rickettsial organisms multiplied in the membrane-bound compartment of DH82 cells and that they morphologically closely resembled rickettsia belonging to the genus Ehrlichia. An indirect fluorescent antibody test using Neorickettsia organisms cultured in DH82 cells showed that all dogs seroconverted 13 to 15 days postinfection. Finally, inoculation of the cell-cultured Neorickettsia organisms into a naive dog reproduced clinically typical salmon poisoning disease which was of greater severity and had a more rapid time course than that in the dogs from which the original isolation was made. On the basis of the clinical and pathologic responses of the dogs in our study, we believe that virulent N. helminthoeca was isolated and cultured in a continuous cell line.

Animals↗
PubMed1991

Periodontal repair in dogs: healing in experimentally created chronic periodontal defects.

A need exists for well-defined animal models to objectively evaluate surgical principles and a possible role for biochemical wound conditioning and biomaterials in promoting periodontal regeneration. To test an existing model for its usefulness in quantitative evaluation of periodontal wound healing, large supraalveolar periodontal defects were surgically created around the mandibular premolars (P2, P3, P4) in left or right jaw quadrants in 5 beagle dogs. The defects were exposed to the oral environment for 6 months and were then subjected to reconstructive flap surgery (chronic defects). Healing in these defects was compared to healing following reconstructive surgery in similar contralateral defects which had not been exposed to plaque and calculus (acute defects). The animals were sacrificed after a 4-week healing period and tissue blocks including teeth and surrounding structures were processed for histometric analysis. Mean defect height (+/- s.d.) for chronic and acute defects amounted to 4.6 +/- 0.3 and 4.4 +/- 0.4 mm, respectively. Mean connective tissue repair to the root surface in chronic defects amounted to 62% (range 49% to 74%) of the defect height. Mean connective tissue repair in the acute defects exceeded 94% of the defect height in 4 of the dogs, but amounted to only 48% in 1 dog. Regeneration of alveolar bone and cementum was limited under both experimental conditions. Root resorption was frequently encountered, whereas ankylosis was seen in only few teeth. This study indicates that healing may vary not only as a result of controlled experimental variables, but also due to differences in biological response between dogs or to fortuitous traumatic factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗
PubMed1991

Assessing student outcomes in a nursing learning assistance program.

This study measured the apparent effectiveness of a Learning Assistance Program (LAP) in second-year baccalaureate nursing students using a process-outcome design. Seventy-eight students participated in LAP and 98 did not. SAT/ACT scores and freshman GPA were the cognitive "input" variables and the end-of-sophomore-year GPA the cognitive "outcome" variable. Affective variables at the beginning and end of the test year were the Study Attitudes and Methods Survey (SAMS) and the Survey of Reading and Study Efficiency (SR/SE). Statistical analysis included stepwise multiple regressions for evaluating the relationship between the process (LAP participation) and outcomes when the entry variables had been accounted for. Attending LAP improved participants' study attitudes and skills scores. There was a significant negative correlation between the degree of LAP participation by lower achieving students and their sophomore-year-ending GPA. This may be related to the fact that students who perform poorly on tests are encouraged to participate in LAP.

Adolescent↗
PubMed1990

Perforation of the colon due to endometriosis.

Endometriosis is a common disease which affects the bowel in 12 to 35% of cases. Despite extensive serosal and intramural involvement, the intestinal mucosa usually remains intact and bowel perforation rarely occurs. We describe a patient with perforation of the sigmoid colon due to endometriosis. To our knowledge, this is the first such case to be reported in the radiologic literature.

Endometriosis↗
PubMed1989

CT diagnosis of perforated duodenal diverticulum.

We present a case of perforated duodenal diverticulum diagnosed preoperatively on computed tomography. This rare but potentially fatal condition has been difficult to detect with more conventional radiographic techniques.

Diverticulum↗
PubMed1989

The duration of the sinus node depolarization on transvenous sinus node electrograms can identify sinus node dysfunction and can suggest its severity.

Catheter recorded sinus node electrograms (SNE) allow visualization of sinus node depolarization (SND). The SND on a bipolar SNE is probably a composite reflecting both P cell action potentials and intranodal conduction. Reduced rate of rise, prolonged action potential duration and/or delayed intranodal conduction might each prolong the SND duration. Thus, SND duration might reflect several clinically important sinus node abnormalities and aid in the recognition of sick sinus syndrome. Moreover, the SND duration might be expected to be the most prolonged in patients with the most severe sinus node dysfunction. To test this hypothesis, we determined SND duration in 32 patients and correlated it with the presence or absence of evidence of sinus node dysfunction by ECG and/or electrophysiological (EP) studies. Seven patients had no sinus node dysfunction (group 1); 10 patients had mild sinus node dysfunction (a single abnormality of corrected sinus recovery time, sinoatrial conduction time, PCLp, or ECG) (group 2); and 15 patients had two or more abnormalities electrocardiographically and/or by EP testing (group 3). The SND duration (mean/range) was 129/95-190 msec in group 1, 151/95-225 msec in group 2, and 196/140-260 msec in group 3. In group 3, three patients who had ECG evidence of sick sinus syndrome and abnormalities on all three EP parameters, the SND duration was 230/200-260 msec. Carotid sinus massage (CSM) was found to prolong the SND duration in 5/7 patients in groups 2 and 3 where the SND could be measured both before and during CSM. CSM was necessary to allow visualization of the SND in 3/7 group 1 patients; thus their recorded values may be falsely long. The normal with a SND duration greater than 150 (190 msec) had it measured during CSM. None of the group three patients with SND duration less than msec had a prolonged CSRT or ECG evidence of sick sinus syndrome. Literature review revealed SNE recordings on 18 patients with sick sinus syndrome on which the SND duration could be measured; it was greater than or equal to 200 msec in all. Thus, the SND duration appears to reflect the presence and degree of sinus node dysfunction. Sinus node dysfunction appears unlikely if the SND duration is less than 150 msec and is likely to be severe if the SND duration is greater than 200 msec.

Adult↗
PubMed1987

Computed tomography of condylar and articular disk positions within the temporomandibular joint.

The computed tomograms of temporomandibular joints in 25 patients (41 joints) were retrospectively evaluated for condylar position and joint space with General Electric computer software. Computed tomography scans of the temporomandibular joint were made in the axial plane with the teeth in centric occlusion, and measurements were made from vertically reformatted images. Interarticular joint spaces were measured anterosuperiorly, superiorly, posterosuperiorly, and posteriorly from the condylar surfaces. This was repeated in five equidistant (3.1 mm) serial sagittal planes across the condyle, beginning and ending, on average, 2.5 mm from the lateral and medial condylar poles. Articular disk positions (anterolateral, anterior, anteromedial, medial, and normal) were correlated with condylar position. Significant differences between disk positions and joint spaces were found most frequently in the anterosuperior and the superior joint interval. When the disk was positioned normally, the anterosuperior joint space was consistent (1.5 to 2.0 mm) across the joint (standard deviation, 0.3 to 0.8 mm). The superior, the posterosuperior, and the posterior joint spaces in the normal joint were greater than the anterosuperior joint space. When the disk was anterior to the condyle, the anterosuperior joint interval was widened. When the disk was medial, the superior joint space was significantly wider than normal across the breadth of the condyle. In those joints in which the disk was anteromedial, there was an absence (0.2 mm) of joint space, and this occurred in all areas of the condyle except in its medial one fourth. In the internally deranged joint, joint space narrowing may be focal in nature.

Adolescent↗
PubMed1987

Smoking behaviour of student nurses enrolled in diploma, associate degree and undergraduate nursing programmes.

Because the literature shows that cigarette smoking is a major causative factor in the occurrence of chronic illness, lung cancer is becoming more common in women than breast cancer, nurses smoke more than any other group of health care providers and studies have not examined differences of smoking among the associate degree, undergraduate and diploma levels of nursing, this study was designed to examine selected health behaviours and their relationship to cigarette use among Alabama senior student nurses, and to determine smoking prevalence by level of educational preparation. A sample of senior associate degree, undergraduate and diploma student nurses in Alabama responded to an 87-item questionnaire which was personally administered by the investigator in a classroom setting. Twenty-two of the 87 items were used to compile the demographics, prevalences and health behaviours reported here. The remaining items were used to develop a sequence of information required to test Ajzen and Fishbein's Theory of Reasoned Action and are beyond the scope of this article. Though there was no significant difference of smoking prevalence among educational levels, there was a trend for increased smoking from undergraduate to diploma level with prevalences of: total sample, 26.2%; diploma, 30%; associate degree, 26%; and undergraduate, 24%. Health behaviours which were significantly different between smoking and non-smoking student nurses were breakfast frequency and coffee consumption. Having a regular exercise routine was not significant. Males smoked significantly more than females. More older nurses (over 40 years) smoked than younger nurses. The findings reported here are useful to the development of health education strategies designed to reduce and prevent cigarette use among student nurses.(ABSTRACT TRUNCATED AT 250 WORDS)

Alabama↗
PubMed1983

Food habits and preferences of Vietnamese children.

In this study, information on food preferences and intake frequencies of 70 Vietnamese children was gathered by means of a questionnaire. The purpose was to compare the dietary habits of children who had been in the U.S. for more than one year with those of children arriving within the past year (1981). The results showed that children less than six years old who came to California more than one year ago consumed green leafy vegetables less frequently (p less than 0.01) and vitamin supplements more frequently (p less than 0.01) than those who came here recently. In the older groups (greater than 6 yrs), those who have been resident in the U.S. for more than one year consumed peanut butter and sweets (ice cream, pies, milkshakes) more frequently than those who had just arrived (p less than 0.001 and p less than 0.05, respectively). Older children (age greater than 6 yrs) who had been in the U.S. longer preferred American foods more than those who had just come (p less than 0.01). The majority of all children ate fruits as snacks. The consumption of rice, eggs, cheese, milk, meats and fruit juice was not significantly different in any of the four groups. This study also revealed a great need of nutrition education for the Vietnamese refugee mothers. Recommendations for planning nutrition education for this population are provided.

Child↗
PubMed1980

Prolongation of proton spin lattice relaxation times in regionally ischemic tissue from dog hearts.

Proton NMR techniques were used to characterize acutely ischemic myocardial tissue from the dog. Ligation of the left anterior descending coronary artery for 30 min resulted in a consistent prolongation of the proton spin-lattice relaxation times (T1) in samples from regionally ischemic heart muscle when compared with T1 values for nonischemic areas from the same hearts. The relative prolongation of relaxation times in ischemic tissue was found to increase as the duration of ischemia was extended to 60 or 120 min. T1 values for ischemic tissue were not directly related to tissue levels of high-energy compounds, lactate, or hydrogen ions but largely reflected the increased water content of the regionally ischemic myocardium. Proton NMR analysis provides a means of identifying acute regional ischemia in heart tissue, and in the future may permit three-dimensional imaging of the heart in vivo.

Animals↗
PubMed1977

Influence of prostaglandin precursors and synthesis inhibitors in vascular bed perfused without a pump.

The present investigation was coducted to examine the role of endogenous prostaglandin (PG) on blood flow and arenergic responses in the paw vasculature perfused without a pump. The PG precursors, arachidonic acid and dihomo-gamma-linolenic acid, given i.a. caused only small increments in paw blood flow which were much less than that caused by PGE2 and PGE1. The i.a. administration of the PG synthesis inhibitors, indomethacin, meclofenamate and naproxen, caused a decrease in paw blood flow and increase in vascular resistance, whereas eicosa-5,8,11,14-tetraynoic acid had no significant effect. Vasoconstrictor responses evoked by norepinerphrine were unaffected after administration of indomethacin or eicosa-5,8,11,14-tetraynoic acid, whereas slight potentiation of the response to sympathetic nerve stimulation was obtained after indomethacin. These results suggest that in the cutaneous vascular bed of the paw, endogenous PG decreases the vascular resitance, but plays only a minor adrenergic modulating role, and then only on the response to adrenergic nerve stimulation.

5,8,11,14-Eicosatetraynoic Acid↗
PubMed1975

Aneurysm of saphenous vein bypass graft to coronary artery.

A few cases of aneurysmal dilatation of autogenous vein grafts to peripheral arteries have been reported. However, to our knowledge, no case of this complication in coronary artery vein bypass grafts have been found. We are presenting a case of a vein graft aneurysm which appeared 6 months postoperatively. The patient had had an aortic valve replacement and a vein bypass graft to the right coronary artery.

Adult↗