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Biomedical subjects

S Jenkins

Publications and source records attributed to S Jenkins.

At least 109 records · Page 6Linked to original sources
PubMed1990

Factors related to job satisfaction and autonomy as correlates of potential job retention for rural nurses.

This study of 167 nurses in 10 rural Georgia agencies examines the relationships among personal characteristics, factors of job satisfaction, autonomy, and job retention. The findings indicate that, contrary to expectations, personal characteristics (e.g., age, education, salary, marital status, and number of dependents) are not strong predictors of job retention in this sample. Some of the factors of job satisfaction do correlate negatively with indicators of impending job change, but the strongest relationships were those related to nursing autonomy. The study concludes that, of the variables studied, autonomy was the most effective predictor of job satisfaction and intention to remain in the current position.

Decision Making, Organizational↗
PubMed1989

Role of angioplasty in patients with previous coronary artery bypass surgery.

Fifty-nine patients with previous coronary artery bypass surgery (CABG) underwent coronary artery or vein graft angioplasty following a recurrence of symptoms, 141 lesions were attempted in 70 procedures. The overall angiographic success rate was 77%. Some angiographic success was achieved in 83% of patients. Complications included myocardial infarction in three (4.3%), death in one (1.4%), and iliac artery thrombosis in one (1.4%). No patients were referred for urgent surgery. Twenty-eight patients have undergone repeat coronary arteriography after 7.5 +/- 2.6 months (mean +/- SD), and 31% of lesions have recurred. Fifty-eight percent of patients without recurrence at follow-up continue to have improved symptoms. Treadmill exercise time was significantly prolonged in patients in whom all attempted lesions had been successfully dilated and in those in whom only some lesions were dilated. Our experience suggests that approximately 29% of patients with recurrence of angina following CABG may be suitable for angioplasty.

Adult↗
PubMed1989

Studies on the effect of toothpaste rinses on plaque regrowth. (I). Influence of surfactants on chlorhexidine efficacy.

A number of compounds have been added to toothpastes to inhibit plaque regrowth. The inclusion of cationic antiseptics, such as chlorhexidine, poses formulation difficulties because of interactions with other ingredients particularly anionic detergents. More recently, Triclosan/zinc citrate formulations have been shown effective plaque inhibitors. The aim of this study was to compare a commercially available 0.2% Triclosan/0.5% zinc citrate toothpaste with a number of experimental 0.5% chlorhexidine/detergent toothpastes for effects on plaque regrowth over 4 days. Subjects rendered plaque free at each baseline rinsed twice a day with toothpaste slurries and disclosed plaque was scored at the end of each period. All toothpastes significantly reduced plaque by comparison with a control toothpaste, but were significantly less effective than a 0.2% chlorhexidine rinse. Some significant differences in favour of one chlorhexidine toothpaste were noted but these were small in magnitude. Whether the plaque inhibition obtained with Triclosan/zinc citrate toothpaste was greater than would be expected from other commercially available preparations cannot be determined from this study and is the subject of a further investigation.

Adult↗
PubMed1989

Studies on the effect of toothpaste rinses on plaque regrowth. (II). Triclosan with and without zinc citrate formulations.

Encouraging findings have been reported for the effects of Triclosan/zinc citrate toothpastes on plaque regrowth and in some studies gingival health. To date, commercially-available toothpastes contain 0.2% Triclosan with or without 0.5% zinc citrate. The aim of this study was to evaluate the effects on 4-day plaque regrowth, of a number of 0.2% Triclosan toothpastes with or without zinc citrate. All of the toothpastes contained varying levels of anionic detergent sodium lauryl sulphate and were compared with a commercially available toothpaste without Triclosan or zinc citrate and a 0.2% chlorhexidine mouthrinse. The toothpastes were used as slurry twice a day and plaque regrowth scored by area and the criteria of the debris index. Plaque inhibition was significantly greater with the chlorhexidine mouthrinse than with all of the toothpastes. There were no significant differences in plaque scores between any of the toothpastes. It would appear that at the concentration of 0.2% Triclosan with or without 0.5% zinc citrate provides little if any additional benefit to plaque inhibition to that produced by a conventional toothpaste containing sodium lauryl sulphate.

Adult↗
PubMed1989

Proposed field evaluation of a rabies recombinant vaccine for raccoons (Procyon lotor): site selection, target species characteristics, and placebo baiting trials.

Prior to a limited field application of an orally-administered vaccinia-rabies glycoprotein (V-RG) recombinant virus vaccine for wildlife, background data were obtained for the proposed site on Parramore Island, Virginia (USA). Mammalian target and nontarget species, potentially at risk for exposure to vaccine were inventoried. Placebo baiting trials with a fishmeal polymer bait resulted in high bait disturbance (88 to 100%), primarily by raccoons (Procyon lotor), with infrequent visitation and no evidence of bait consumption by deer (Odocoileus virginianus), small mammals or avian species. Definitive bait acceptance rates by raccoons (indicative of bait ingestion) were difficult to accurately determine based exclusively on premolar and vibrissae samples collected antemortem from live-trapped raccoons for tetracycline and rhodamine B biomarker analyses, respectively. Bait acceptance rate was more accurately determined during a pilot baiting trial conducted on North Island, South Carolina, when mandibles (postmortem samples) were examined for tetracycline incorporation. Parasitologic findings in raccoons on Parramore Island included Hepatozoan procyonis, Phagicola angrense and Physaloptera rara and a variety of incidental microscopic lesions, and provided baseline pathological data for comparison subsequent to V-RG vaccine application. A population density estimate of one raccoon/2.7 ha was calculated using mark-recapture data for comparison after vaccine deployment. Limited reproductive data, including estimates of pregnancy rates by palpation, the number of live kits/litter live-trapped with previously pregnant raccoons or observed in the dens of radio-collared raccoons, was gathered to assess the effect of proposed oral vaccination with V-RG vaccine. Home ranges were assessed by radio-telemetry of 15 raccoons; all radio-collared raccoons currently reside on Parramore Island.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

A multicenter model for examining in vitro susceptibilities of bacteria to antibiotics.

In vitro bacterial susceptibility data are often considered in both hospital formulary and antibiotic prescribing decisions. In this multicenter study, susceptibility data from 105 United States hospitals resulted in a database containing 211,142 isolates for 31 different bacteria and 38 antibiotics. To identify susceptibility patterns of bacteria to antibiotic alternatives, this computerized database was subjected to confidence interval analysis, while controlling for potential sources of random error. This paper describes the multicenter study design and provides several examples of the type of information the analysis can provide to P & Committee members and to practitioners who ultimately must make decisions regarding antibiotic use, sometimes without the benefit of complete hospital-specific historical antibiogram data. Limitations on the interpretation of aggregate in vitro susceptibility data gained from multiple institutions are also discussed.

Anti-Bacterial Agents↗
PubMed1989

The effects of medetomidine, an alpha 2-adrenergic agonist, on ventilatory drive in the dog.

alpha 2-Adrenergic agonists have been used as potent adjuncts to anesthesia and have anesthetic properties themselves. For this reason, we studied the effects of medetomidine, and isoflurane (1 MAC) on ventilatory drive in dogs. Six chronically tracheotomized mongrel dogs were studied during spontaneous ventilation. Arterial blood samples were analyzed for pH, PaCO2, and PaO2. Airway O2, CO2, N2, and isoflurane were continuously monitored using a mass spectrometer; respiratory rate was determined. The hypercapnic ventilatory response was assessed using the Read rebreathing technique. Control measurements were made under isoflurane anesthesia. Fifteen minutes after the medetomidine (20 ug/kg) was given and the isoflurane discontinued, all measurements were repeated. Isoflurane levels were 1.38 volume % during the isoflurane test period and had declined to 0.3 volume % by the time the medetomidine measurements were obtained. The slope of the CO2 response curve was significantly steeper after medetomidine (0.582 vs 0.269 1.min-1.mmHg), suggesting less respiratory depression when compared to the measurements under isoflurane. PaCO2 and endtidal CO2 were significantly lower in the medetomidine group. No other significant differences were found. Under these conditions, medetomidine (20 ug/kg) resulted in normal blood gas values with less depression of the hypercapnic response curve than under isoflurane anesthesia.

Adrenergic alpha-Agonists↗
PubMed1989

Toothpastes containing 0.3% and 0.5% triclosan. I. Effects on 4-day plaque regrowth.

Triclosan has been added to toothpaste formulations, alone or with zinc salts, to reduce plaque regrowth. The most encouraging results have been obtained with triclosan/zinc formulations particularly at the higher concentrations of one or both agents. Formulations containing 0.2% triclosan alone have shown less promise and the aim of this study was to measure plaque regrowth over 4-day periods with the use of 0.3% and 0.5% triclosan toothpastes with and without the addition of a copolymer, polyvinyl methyl ether maleic acid (PVM/MA) and to compare the findings with a conventional fluoride/anionic detergent based toothpaste and a 0.2% chlorhexidine mouthrinse. The method was a no oral hygiene randomized 6 times crossover study using the toothpaste slurry rinsing method. Plaque was recorded by a plaque index and by area. Three of the four triclosan toothpastes reduced plaque regrowth significantly compared with the placebo, with no significant differences among the triclosan toothpastes. Plaque scores were always significantly lower with the chlorhexidine mouthwash compared to all toothpastes. The results suggest that at 0.3% to 0.5% triclosan alone or with a copolymer toothpaste may be a benefit to oral hygiene, but whether this is sufficient to affect gingival health requires further clinical evaluation. Further research would also appear indicated to determine optimal levels for the copolymer concentrations in toothpastes.

Adult↗
PubMed1989

Toothpastes containing 0.3% and 0.5% triclosan. II. Effects of single brushings on salivary bacterial counts.

For antimicrobials such as chlorhexidine antiplaque activity appears due to persistence of considerable antimicrobial action in the mouth. The substantivity of antimicrobial compounds can be evaluated by measuring the magnitude and duration of salivary bacterial counts following a single exposure. Such data has been shown to correlate with plaque inhibitory properties of antimicrobial compounds. This study measured the effects of single brushings with 0.3% and 0.5% triclosan with or without PVM/MA copolymer in toothpastes on salivary bacterial counts in 14 young adults. The results were compared with single rinsing with a 0.2% chlorhexidine solution, water and a single brushing with a commercial fluoride toothpaste. The study was a 7 cell cross-over design, randomized using a 7x7 latin square design. Chlorhexidine produced large and significant reductions which persisted to the 7 hour measurement time with no indication of count recovery at this time. The triclosan pastes containing the copolymer produced significant reductions which did not persist beyond 5 hours and evidence of bacterial count recovery with a paste containing triclosan but no copolymer (increments) was apparent after 30 minutes. The water and control paste produced no significant effects on counts. Intertreatment comparisons showed the chlorhexidine rinse more effective than all other preparations in all time periods. Some of the triclosan toothpastes containing the copolymer produced significantly greater effects compared to water or the control paste at some, but not all time periods. There was little difference between the triclosan pastes with the copolymer. Nevertheless, the duration and magnitude of salivary bacterial count reductions seen with the triclosan toothpastes may explain the plaque inhibition effect.

Adult↗
PubMed1988

Routine use of laser Doppler flowmetry for monitoring autologous tissue transplants.

This is a report of a prospective study in which 41 consecutive autologous tissue transplants were monitored using the Laserflo BPM model 403 laser Doppler monitor (TSI Inc., St. Paul, MN). Flaps were monitored both intraoperatively and postoperatively, and clinical flap monitoring was compared with laser Doppler monitoring. Twenty-nine flaps had no problems as indicated by clinical or Doppler measurement. Twelve flaps underwent 13 reexplorations; one flap was explored twice. Five venous and five arterial anastomoses were corrected, with complete survival of the flaps. Three hematomas were evacuated. Two of these flaps failed. There were no instances where the laser Doppler indicated a problem with flap viability that subsequently did not merit reexploration. There were no instances of flap failure undetected by the laser Doppler. In comparison to the clinical monitoring, laser Doppler monitoring was more rapid and more precise in identifying problems with the flap. The use of this monitor has improved our salvage rate for flap reexploration from 50 to 85% and has provided a more objective standard for both nurses and physicians to evaluate flaps in the perioperative period.

Graft Occlusion, Vascular↗
PubMed1988

The mechanism of action of chlorhexidine. A study of plaque growth on enamel inserts in vivo.

Controversy exists concerning the mode of action of chlorhexidine in plaque inhibition. This study attempted to determine whether an oral reservoir of chlorhexidine was necessary for plaque inhibition. Plaque growth on enamel under the influence of topically applied or rinsed chlorhexidine was closely monitored by clinical scoring, bacterial culturing and scanning electron microscopy. Thus, 3 subjects wore removable acrylic appliances containing enamel inserts. In the first regimen, inserts on one side of the appliances were exposed to 0.2% chlorhexidine and on the other, water for 1 min twice a day for 14 days. In the second regimen, subjects rinsed with 0.2% chlorhexidine for 1 min twice a day for 14 days with the appliances in situ. Results demonstrated that plaque growth assessed by the 3 study methods was very small on chlorhexidine-treated inserts by comparison with water-treated specimens. Importantly, inserts treated with chlorhexidine topically or by rinsing could not be distinguished by any method of evaluation. It is concluded that chlorhexidine achieves plaque inhibition as a result of an immediate bactericidal action during the time of application and a prolonged bacteriostatic action as a result of adsorption to the pellicle coated enamel surface. Consistent with other clinical studies, it is apparent that a progressively desorbing oral reservoir of antiseptic is not the mechanism by which chlorhexidine achieves plaque inhibition on teeth.

Administration, Topical↗
PubMed1987

Reduced cell death in skin flaps in rats treated with difluoromethylornithine.

The beneficial effects of alpha-difluoromethylornithine (DFMO) were assessed in a model of peripheral ischemia. DFMO is an irreversible inhibitor of ornithine decarboxylase (ODC), the initial enzyme in the production of polyamines. A 7 x 7 cm rat abdominal skin flap was surgically raised based on two inferior epigastric nerve, artery, and vein pedicles. One of the pedicles was then ligated and the skin was sutured back in place. Necrosis of skin was assessed 2 and 7 days after surgery. The rats were divided into four groups: control, DFMO, DFMO + polyamines, and polyamines alone. DFMO was administered in drinking water at 0.2%. Polyamines (putrescine, spermidine, and spermine) were each administered by daily i.p. injection at a dose of 10 mg/kg. The percentage of necrosis of the area of skin at risk in controls was 65 +/- 2% (mean +/- SEM). Necrosis was significantly reduced with DFMO (19 +/- 1%), with DFMO plus polyamines (37 +/- 3%), or with polyamines alone (41 +/- 2%). Protein synthesis and ornithine decarboxylase activity in the skin were both significantly decreased by DFMO. These studies demonstrate that DFMO protects skin from ischemic damage at least in part through actions on polyamine metabolism.

Animals↗
PubMed1986

Naturally occurring and induced ganglion cell death. A retinal whole-mount autoradiographic study in Xenopus.

The retina in frogs grows continuously throughout the whole life of the animal by the addition of rings of cells at the ciliary margin. Naturally occurring neuron death cannot, consequently, be established by counting surviving neurons. A new approach, retinal whole-mount auto-radiography was introduced in this study to estimate cell loss occurring in the ganglion cell layer over a long period of time. 3H-thymidine injection at stage 53 (midlarval stage) labels a ring of cells, thereby marking the extent of retina formed up to the time of isotope administration. In the present study the number of neurons in the ganglion cell layer within the autoradiographically identified central retinal sector was estimated from midlarval stage to 6 months after metamorphosis in Xenopus laevis. The mean neuron number in the central retinal sector formed up to stage 53 was 17,420 and this was reduced by 20% to 13,515 by 6 months after metamorphosis. Optic nerve section at the time of isotope injection and subsequent regeneration brought about a reduction of the number of surviving neurons in the part of the retina formed up to stage 53 to 7,720, or to about 57% of the normal neuron number in an equivalent retinal area of an intact eye of the same age. A further reduction to 20% of normal neuron population was observed in retinae where the optic nerve failed to regenerate. The surviving neurons are assumed to be amacrine cells. The bulk of natural neuron loss in the retinal centre occurs during premetamorphic stages while little further loss takes place in the next 6 months suggesting that the underlying mechanism is a fine tuning of the developing retinal projections.

Animals↗
PubMed1986

Endometriosis: pathogenetic implications of the anatomic distribution.

The authors have reassessed the anatomic distribution of ectopic endometrium by the laparoscopic study of the location of implants, adhesions, and uterine position in 182 consecutive patients with infertility and endometriosis. The ovary was the most common site of implants with 54.9% having either unilateral or bilateral involvement. This was followed, in order of frequency, by the posterior broad ligament (35.2%), the anterior cul-de-sac (34.6%), the posterior cul-de-sac (34.0%), and the uterosacral ligament (28.0%). Adhesion formation followed the same anatomic distribution. No patients were noted to have endometriosis of the cervix and vagina. Endometriosis of the anterior compartment (anterior cul-de-sac, anterior broad ligament, and anterior uterine serosa) was significantly more common in patients with anterior uteri (40.7%) versus patients with posterior uteri (11.8%, P less than .0005). Exclusive anterior compartment disease was found only in patients with anterior uteri, and significantly more commonly in patients with severely anteflexed uteri (P less than .005). These data suggest that factors influencing implantation of retrograde menstrual debris include: the dependent pooling of peritoneal fluid as affected by uterine position; epithelial cell type at the site of implantation; unique ovarian susceptibility; route of entry; and mobility of the pelvic structures. The data support the Sampson hypothesis of retrograde menstruation as the primary model of development of endometriosis.

Broad Ligament↗