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At least 397 records · Page 22Linked to original sources
PubMed2000

Predominant contribution of the G protein-mediated mechanism to NaF-induced vascular contractions in diabetic rats: association with an increased level of G(qalpha) expression.

The purpose of this study was to determine the mechanism responsible for alterations in NaF-induced contractions of blood vessels from streptozotocin-induced diabetic rats. In the presence of AlCl(3), NaF (>/=7.5 mM) produced significantly greater contractions in diabetic aorta and mesenteric artery compared with age-matched controls. Pretreatment with 1 microM nifedipine eliminated the enhanced contractile responses of diabetic vessels to NaF, resulting in no difference in the magnitude of NaF-induced contractions between control and diabetic vessels. In the presence of 100 microM deferoxamine, an Al(3+) chelator, NaF-induced contractions of diabetic vessels were markedly attenuated, whereas only the responses to lower concentrations of NaF were reduced in control vessels. No significant difference was found in the peak amplitude of transient contractions induced by 10 microM cyclopiazonic acid between control and diabetic vessels. The addition of 10 microM okadaic acid produced attenuated contractions in diabetic vessels. These findings indicate no involvement of the inhibitory effects of NaF on endoplasmic reticular Ca(2+)-pump ATPase and protein phosphatases in the genesis of the enhanced responsiveness of diabetic vessels to NaF. Western blot analysis showed a 2.5-fold increase in the expression of G(qalpha) in diabetic aortic membranes. In contrast, the G(ialpha) level was modestly decreased and the G(salpha) and G(betagamma) levels were unchanged in diabetes. The present results suggest that enhanced vascular contractions to NaF in diabetes is attributed predominantly to a G protein-mediated Ca(2+) channel activation that results from markedly increased G(qalpha) expression in vascular tissues under this pathological state.

Aluminum Chloride↗
PubMed2000

Remission of facial and scalp hyperhidrosis with clonidine hydrochloride and topical aluminum chloride.

Axillary and palmar hyperhidrosis are featured prominently in the literature, but no previous studies have detailed a treatment regimen for specific excessive localized sweating of the face and scalp. In this report, a patient was treated for this condition with a combination of clonidine hydrochloride (0.3 mg to 0.4 mg, with 0.25 mg to be taken at bedtime, to prevent daytime sedation) [corrected] and a topical solution of 20% aluminum chloride in anhydrous ethyl alcohol (Drysol). Over a period of 2 or 3 weeks, the patient achieved a complete remission of symptoms, while having only mild side effects. The treatment regimen also had the added advantage of lowering generalized anxiety.

Administration, Topical↗
PubMed2000

Herbal anti-inflammatory agents for skin disease.

Herbs have been used in clinical medicine for thousands of years. However, it is only in recent times that we have been able to employ scientific methods to prove the efficacy of many of these herbs and to give us a better understanding of their mechanisms of action. This article will focus on the use of herbs in various dermatological conditions characterized by inflammation and pruritus. Topical preparations of many of these herbs are more commonplace in Europe. However, their availability is increasing in the US. As this is occurring we are witnessing a growing marriage between alternative and traditional medicines.

Aloe↗
PubMed2000

Outcomes of venous ulcer care: results of a longitudinal study.

A longitudinal study involving 81 patients with venous ulcers was conducted to explore the outcomes and cost of wound care in a home healthcare (HHC) setting and an outpatient care setting. Ulcers were managed with a saline gauze or hydrocolloid dressing and compression hosiery, or covered with an Unna's boot. Outcomes did not vary between physician's office and home care. Patients preferred home care, but costs and charges were much higher for HHC than for patients managed in the physician's office. Recurrence rates and costs varied greatly. Eighty-eight percent of ulcers in the saline dressing group did not heal or recurred compared to 21% of ulcers in the Unna's boot and 13% of ulcers in the hydrocolloid dressing group. The data also suggest hydrocolloid dressings are more cost-effective than Unna's boot or saline-gauze dressings. Controlled clinical studies to ascertain the cost-effectiveness of venous ulcer care in different patient care settings and the use of different treatment modalities, as well as care system oriented toward outcome for the patient rather than service, design, and distribution, are needed.

Adult↗
PubMed2000

Effect of 3 medicaments on the dimensional accuracy and surface detail reproduction of polyvinyl siloxane impressions.

OBJECTIVE: The purpose of this study was to determine the effect of retraction cord medicaments (aluminum chloride, ferric sulfate, and ferric subsulfate/ferric sulfate) on the dimensional accuracy and surface detail reproduction of polyvinyl siloxane impressions. METHOD AND MATERIALS: Polyvinyl siloxane impressions were made of standardized metal dies (American Dental Association [ADA] specification No. 19) treated with 1 of the 3 retraction cord medicaments. Dimensional accuracy was evaluated by comparing the average length of a line in the impressions to the standard die. Surface detail reproduction was evaluated by viewing the impressions under low-angle illumination at x10 magnification. Reproduction was considered satisfactory if 2 of 3 horizontal lines were reproduced continuously. The dies were also evaluated under the microscope before the impression was made. RESULTS: The medicaments did not significantly effect the dimensional accuracy; mean shrinkage was within ADA guidelines in the treatment groups. All of the medicaments had an adverse effect on surface detail reproduction. These effects were statistically significant compared to the untreated control. CONCLUSION: Although the changes in dimensional accuracy were within ADA guidelines, the surface detail reproduction was modified such that the impression would be considered clinically unacceptable. For optimal results, care must taken to remove all traces of these retraction cord medicaments prior to recording of a polyvinyl siloxane impression.

Aluminum Chloride↗
PubMedDate not supplied

Dietary administration of tannic acid lowers plasminogen activator activity in the liver of C3H hepatoma bearing male mice.

BACKGROUND: This study was undertaken to investigate if low-dose dietary administration of tannic acid exerts its chemopreventive activity on hepatocarcinogenesis in male C3H mice through changes of plasminogen activator activity (PAA), plasminogen activator inhibition (PAI) or plasmin inhibition (Pl) in the liver of C3H hepatoma bearing male mice. MATERIALS AND METHODS: Tannic acid was administered in the drinking water of hepatoma bearing C3H mice, in a concentration of 0.0075% (group B), 0.015% (group C) and 0.03% (group D) for 9 months. PAA, PAI and PI were measured by spectrophotometric methods in macroscopically healthy liver regions. RESULTS: Tannic acid induced a decrease of PAA (53%) and an increase of PAIs (50%) in the livers of group D while tannic acid received mice showed a dramatic decrease in liver carcinomas incidence (0% vs 33.3% in the control group). CONCLUSION: The decrease of PAA in the liver of C3H hepatoma bearing male mice, might be correlated with the chemopreventive activity of tannic acid in hepatoma development.

Animals↗
PubMed2000

Micromorphological investigation of noncarious cervical lesions treated with demineralizing agents.

PURPOSE: The purpose of this study was to examine the micromorphology of noncarious cervical lesions (NCCL) and the change occurring after acid conditioning. MATERIALS AND METHODS: Nine wedge-shaped lesions, 9 saucer-shaped lesions, and 5 third molars with prepared cervical cavities were used. All NCCLs exhibited a hard, smooth surface with no discoloration. The teeth were sectioned and divided into three groups, each containing the three lesion types. Teeth in Group I were not etched, and teeth in Groups II and III were etched with 35% phosphoric acid and 20% polyacrylic acid/3% aluminum chloride, respectively. Field emission SEM and atomic force microscopy were used to examine the lesion surfaces. RESULTS: The surfaces of the prepared cervical (control) lesions were covered with a smear layer. Treatment with phosphoric acid and polyacrylic acid resulted in removal of the smear layer, although some residual smear layer was found on the surface treated with polyacrylic acid. The images of the untreated surfaces of NCCL showed highly mineralized dentin with complete obliteration of the dentinal tubules. After treatment with phosphoric and polyacrylic acids, the images revealed demineralization of the surface, which was more pronounced on those treated with phosphoric acid. CONCLUSION: The mineral deposits on the surface of NCCL decreased the effect of acid conditioning. Although there was no apparent difference between the two forms of NCCL used in this study, further work is needed to better understand these lesions.

Acid Etching, Dental↗
PubMed2001

Properties of flocs produced by water treatment coagulants.

Hydrolyzing coagulants are extensively used in water and wastewater treatment, often under conditions where hydroxide precipitation is important, giving "sweep flocculation". Pre-hydrolyzed coagulants, such as polyaluminium chloride (PACl) are also widely used and have several advantages over traditional additives, such as aluminium sulfate. Their action is usually discussed in terms of cationic species and charge neutralization. However, precipitation may also be important and this aspect has not been considered in detail. The present work has compared the action of alum and three commercial PACl products on model clay suspensions. The conventional jar test procedure has been used, along with measurements of settled floc volume and dynamic monitoring of floc formation and break-up by an optical technique. The latter method gives very useful information on the nature of the flocs produced and their response to different shear conditions. It is clear from the results that the PACl products form larger and stronger flocs than alum. With all coagulants floc breakage appears to be essentially irreversible. Sediment volumes are slightly lower for flocs produced by PACl than by alum, but the value is proportional to the dosage in all cases.

Alum Compounds↗
PubMedDate not supplied

SEM study of different treatments of the smear layer on different cavity walls.

The present study evaluated the effects of slightly demineralizing treatments on dentinal cavity walls, since some recently developed adhesive procedures are applied over the smear layer. Ten experimental treatments--mechanical, chemical or mechanical/chemical--were applied on MOD cavity walls prepared in vitro with diamond burs. The dentinal surface of a lateral and of a pulpal wall of each cavity was evaluated through scanning electron microscopy, and the effects of the treatments were compared. All treatments except air/water spray removed some of the smear layer, and slight differences were observed regarding the studied cavity walls: on dentin from pulpal walls the enamel hatchet associated with tannic acid produced a better effect than the other treatments, and on dentin from lateral walls the biological detergent rubbed with cotton pellets was a little more effective than the other treatments. The effect of the smear layer treatment on dentin is different according to the wall and to the applied treatment.

Acid Etching, Dental↗
PubMed2002

An innovative tissue-retraction material.

One of the most challenging problems of fixed prosthodontics is tissue control. Gingival retraction before a final impression can be very frustrating and time consuming. Many different techniques have been developed over the years to accommodate the clinician's struggle to obtain tissue control and achieve an ideal impression. This article discusses several of those techniques and how the new, innovative product Expa-syl can be incorporated into these techniques. Expa-syl is an injectable retraction and hemostatic agent that can cause little trauma to the tissue as well as save the dentist time and money. The author elaborates on the multiple uses of Expa-syl and the correct techniques for making this material a successful tool in any dental office.

Adult↗
PubMed2002

Expanded clinical uses of a novel tissue-retraction material.

Impression making for all fixed prostheses requires access to the prosthetic margin while minimally traumatizing the tissue, so that clinicians can provide as much clinical information as possible to the laboratory technician. This information allows the technician to design the prosthesis to meet the criteria of the periodontium and allow the gingival tissues to recover to their original state. Until now, there have been three traditional options in the armamentarium for retraction procedures: packing cord, electrosurgery, and laser surgery. These procedures all have degrees of trauma that vary based on the experience of the clinician. The gingival tissue may be very delicate and susceptible to recession if too much trauma occurs. This article describes an expanded use of Expa-syl, a newly introduced tissue retraction material, as it relates to minimally invasive tissue management, while still providing an ideal gingival tissue environment for long-term health.

Aluminum Chloride↗
PubMed2002

A predictable gingival retraction system.

Predictable tissue retraction for impressions and insertion of restorations can be a laborious task for many dental professionals. The Expa-syl paste retraction system has significantly improved the ability to achieve tissue management even under the most difficult situations and in less time. This article demonstrates the use of this paste retraction system to control tissue for impression making as well as for the insertion of adhesively placed nonmetal restorations.

Adult↗
PubMedDate not supplied

Harvesting and climate effects on organic matter characteristics in British Columbia coastal forests.

As part of investigations into the effects of harvesting old-growth forest, we characterized carbon in five organic matter pools in eight forest chronosequences of coastal British Columbia. Each chronosequence comprised stands in four seral stages from regeneration (3-8 yr) to old-growth (>250 yr), with second-growth stands mostly of harvest origin. Stands were located in two biogeoclimatic subzones with contrasting climate (wetter, slightly cooler conditions on the west coast of Vancouver Island than on the east). Carbon concentrations in fine woody debris (FWD), forest floor (LFH), fine roots from LFH, and two water-floatable fractions from 10 to 30 cm mineral soil (MIN-ROOT, 2-8 mm and MIN-FLOAT, <2 mm) showed no significant effects due to climate, seral stage, or site. There were some significant differences in N concentrations, but none related to seral stage. Carbon-13 cross-polarization with magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectra with principal component analysis of relative areas also showed little harvesting effect, but greater variation related to input of coarse woody debris (CWD) vs. roots high in tannin. Overall, there tended to be more spectral features associated with wood and lignin in the west; whereas some MIN-ROOT samples from the drier east side had aromatic intensity attributed to charcoal. The minimal effects of one harvest on organic matter are most likely due to the large legacy effect; however, more intensive management will probably result in less CWD retention, less charcoal input, and less microsite variability in these pools of poorly decomposed organic matter.

Astringents↗
PubMedDate not supplied

Characterization of high-tannin fractions from humus by carbon-13 cross-polarization and magic-angle spinning nuclear magnetic resonance.

Condensed tannins can be found in various parts of many plants. Unlike lignin there has been little study of their fate as they enter the soil organic matter pool and their influence on nutrient cycling, especially through their protein-binding properties. We extracted and characterized tannin-rich fractions from humus collected in 1998 from a black spruce [Picea mariana (Mill.) Britton et al.] forest in Canada where a previous study (1995) showed high levels (3.8% by weight) of condensed tannins. A reference tannin purified from black spruce needles was characterized by solution 13C nuclear magnetic resonance (NMR) as a pure procyanidin with mainly cis stereochemistry and an average chain length of four to five units. The colorimetric proanthocyanidin (PA) assay, standardized against the black spruce tannin, showed that both extracted humus fractions had higher tannin contents than the original humus (2.84% and 11.17% vs. 0.08%), and accounted for 32% of humus tannin content. Consistent with the results from the chemical assay, the aqueous fraction showed higher tannin signals in the 13C cross-polarization and magic-angle spinning (CPMAS) NMR spectrum than the emulsified one. As both tannin-rich humus fractions were depleted in N and high in structures derived from lignin and cutin, they did not have properties consistent with recaldtrant tannin-protein complexes proposed as a mechanism for N sequestration in humus. Further studies are needed to establish if tannin-protein structures in humus can be detected or isolated, or if tannins contribute to forest management problems observed in these ecosystems by binding to and slowing down the activity of soil enzymes.

Astringents↗
PubMedDate not supplied

Important factors for accurate impressions.

A great preparation is only as good as the impression and die made of it. Attention to every detail is necessary for a successful clinical result. By observing the clinical results, each individual dentist's experience will show the observant operator which technique works best. By combining experience, attention to detail, and patience, it is possible to achieve great fitting, adjustment-free esthetic dentistry.

Astringents↗
PubMedDate not supplied

Effects of pre-soaked retraction cords on the microcirculation of the human gingival margin.

In the direct treatment of cervical lesions and to improve the impression-making procedure prior to fabricating indirect restorations, exposure of the gingival sulcus and control of hemorrhage or gingival fluid seepage are a prerequisite. For gingival displacement, cords impregnated with medicaments are widely used. In this investigation, the authors first studied in vitro the time course of fluid absorption by retraction cords immersed in test solutions. Thereafter, in a clinical trial, they examined the microcirculatory responses of the gingival margin after subgingival insertion and removal of retraction cords pre-soaked in solutions containing saline, AlCl3, Fe2(SO4)3 or epinephrine. Blood flow was recorded using laser Doppler technique. Blood perfusion fell markedly upon inserting the retraction cord, and this response was invariably present with all the compounds tested. After five-minutes, the decrease became less apparent with cords that were impregnated with physiological saline, AlCl3 or Fe2(SO4)3. Removing the cord elicited a prompt, marked and sustained increase in gingival microcirculation. However, removal of the cord impregnated with 0.1% epinephrine failed to reverse the decreased perfusion, and blood flow to the gingival margin remained low over an additional 20-minute observation. The results of this study indicate that with the exception of epinephrine, all retraction substances tested produced gingival hyperemia for operative procedures. Only epinephrine exhibited sustained vasoconstrictor response. It is anticipated that using laser Doppler flowmetry may be a suitable technique to evaluate the appropriate concentration of epinephrine that would elicit topical vasoconstriction.

Absorption↗