Acceptability of silver diamine fluoride as interim measure towards untreated dental caries and its impact on ohrqol among children with HIV: Pilot study.

BACKGROUND: Children with HIV are a special group with limited access to care and high prevalence of dental caries. Silver Diamine Fluoride (SDF) is approved universally for the management of asymptomatic carious lesions but research on the psychological impact of black staining is scarce. AIMS: Effect of silver diamine fluoride (SDF) application as an interim caries management on the child's oral health-related quality of life of children with HIV over a period of 4 months until definitive care was provided. SETTINGS AND DESIGN: A pilot study conducted among children with HIV in a care home. It was a pilot trial to check the acceptability of SDF among these children. METHODS AND MATERIAL: Forty-two children (12.3 ± 3.5 years) participated in this pilot study. Prevalence of caries (DMFT), candidiasis, gingival inflammation, and cervical lymphadenitis was evaluated. OHRQoL inventory (COHIP-SF) was completed by the students at baseline, immediately, 4 months after SDF application. STATISTICAL ANALYSIS USED: One-way ANOVA with post hoc Tukey HSD test. RESULTS AND CONCLUSION: Poor oral hygiene was universal and mean DMFT was 3.2 ± 2.5. OHRQoL was not significantly affected at baseline (26.2 ± 6.4), but immediately following SDF application, OHRQoL was significantly poor (48.7 ± 8.2), remained poor even after 4 months (42.6 ± 6.1). Emotional wellbeing was significantly impacted negatively following SDF application (p < 0.001); whereas oral health, functional wellbeing dimensions were not impacted. SDF should be used with caution among special children as the black discoloration of the teeth can cause emotional trauma and negatively impacting their OHRQoL while trying to improve the same.

Characteristics and outcomes of patients with intellectual disability admitted to a specialist inpatient rehabilitation service.

Rehabilitation services for people with mental illnesses have been extensively researched. However, services with similar aims and specifications for patients with intellectual disabilities (IDs) have had little focus. This study describes the characteristics and outcomes of 21 patients admitted to a specialist ID rehabilitation service over an 8-year time frame. Rather that solely accepting 'step-down' referrals, some patients were referred from community settings. During the study, 20 patients were discharged, 80% to lower levels of service restriction, while 14.3% to higher levels. The study suggested that rehabilitation services have an important role within the wider service model for people with ID. Within the service studied, patients were referred from both higher and lower levels of restriction, suggesting the rehabilitation service 'bridged the gap' between inpatient and community settings, supporting the aim of caring for patients in the least restrictive setting for their needs.

Photosynthetic nutrient-use efficiency in three fast-growing tropical trees with differing leaf longevities.

Differences in nutrient-use efficiency have been attributed to differences in leaf habit. It has been suggested that evergreens, with their longer-lived leaves, and therefore longer nutrient retention, are more efficient than deciduous species in their use of nutrients. In tropical trees, however, leaf life span is not always a function of whole-tree deciduousness, leading to the proposal that nutrient-use efficiency is better related to leaf life span than to leaf habit. It was predicted that potential photosynthetic nutrient-use efficiency (maximum potential photosynthesis/leaf nutrient content) would decrease with increasing leaf life span, whereas cumulative photosynthetic nutrient-use efficiency (carbon assimilated over a leaf's life span/total nutrients invested in a leaf) would increase with increasing leaf life span. Potential and cumulative photosynthetic nutrient-use efficiencies (with respect to nitrogen and phosphorus) were measured for three fast-growing tropical trees: Cedrela odorata L. (Meliaceae), Cordia alliodora (R. & P.) Cham. (Boraginaceae), and Hyeronima alchorneoides Allemão (Euphorbiaceae). Mean leaf life spans of the three species varied about threefold and ranged from 50 to 176 days. The predictions were partially supported: Cedrela odorata had the shortest-lived leaves and the highest potential nitrogen-use efficiency, whereas Hyeronima alchorneoides had the longest-lived leaves and the highest cumulative nitrogen- and phosphorus-use efficiencies. Potential phosphorus-use efficiency, however, was invariant among species. It is suggested that there are potential tradeoffs between leaf characteristics that lead to high potential and cumulative nutrient-use efficiencies. High potential nutrient-use efficiency may be beneficial in high-nutrient environments, whereas high cumulative nutrient-use efficiency may be of greater benefit to species in low-nutrient environments.

Relationship between difficult tracheal intubation and obstructive sleep apnoea.

The upper airway abnormalities predisposing to difficult tracheal intubation may also predispose to obstructive sleep apnoea (OSA). The potential association is important as both conditions increase perioperative risk and patients with a trachea that is difficult to intubate may need assessment for OSA. We determined if patients with difficult intubation are at greater risk of OSA and, if so, whether or not they have characteristic clinical or radiographic upper airway changes. We studied 15 patients in whom the trachea was difficult to intubate and 15 control patients. Each was evaluated clinically (Mallampati score, thyromental distance, neck circumference, head extension), polysomnographically (apnoea-hypoponea index (AHI)) and radiographically (lateral cephalometry). AHI was greater in the difficult intubation group (mean 28.4 (SD 31.7)) compared with controls (5.9 (8.9)) (P < 0.02); eight of 15 patients in the difficult intubation group and two of 15 in the control group had an AHI > 10 (P < 0.03). Difficult intubation, but not OSA, was associated (P < 0.05) with a smaller thyromental distance and mandibular length, and greater soft palate length. Both difficult intubation and OSA were associated (P < 0.05) with a greater Mallampati score, anterior mandibular depth, and smaller mandibular and cervical angles. OSA, but not difficult intubation, was associated (P < 0.05) with increased neck circumference, tongue area and craniocervical angle, and decreased head extension, mandibular ramus length and atlantooccipital distance. We conclude that difficult intubation and OSA are related significantly. They share anatomical features which act to reduce the skeletal confines of the tongue. Patients with OSA may compensate, when awake, by increasing craniocervical angulation, which increases the space between the mandible and cervical spine and elongates the tongue and soft tissues of the neck.

cAMP signaling mechanisms with aging in rats.

Blunted cAMP responses to beta-adrenergic agonists play a major role in diminished smooth muscle relaxation in blood vessels from older animals, although the mechanisms remain uncertain. A diminished cAMP response could potentially arise from changes in the expression of adenylyl cyclase-coupled G proteins, such as a diminished expression of Gs or an increased expression of Gi. We tested the hypothesis that a loss in Gs or increased expression of Gi could occur in tissues such as the aorta, heart and kidney with aging, which would provide a unifying explanation for blunted cAMP responses to many hormones with aging in a variety of cells. Using Western blotting with specific antibodies, we found no generalized changes in G protein expression with aging. Also, injection of pertussis toxin (which functionally inactivates Gi) into older animals did not restore vascular relaxation mediated by beta-adrenergic receptors. We previously found an elevated ratio of regulatory to catalytic subunits of protein kinase A in the aorta of older rats, which would tend to impair activation of the catalytic unit; this alteration was not generalized to other organs such as the heart and kidney. Old rats fed a low salt diet did not show the restored beta-adrenergic agonist-induced vasodilation previously found in elderly humans, suggesting that there are species differences in the development of this deficit. Altogether, these results suggest that altered G protein expression does not provide a general explanation for blunted activation of adenylyl cyclase with aging.

Desensitization of alpha-adrenergic receptor-mediated smooth muscle contraction: role of the endothelium.

Desensitization of alpha-adrenergic receptor-mediated smooth muscle contraction occur in aortas from New England Deaconess Hospital (NEDH) rats harboring pheochromocytoma (PHEO) and following chronic exposure to the alpha-adrenergic agonist phenylephrine in vitro. Endothelium is known to release an endothelial cell-derived relaxing factor that promotes smooth muscle relaxation. We wondered if the endothelium might contribute to the desensitization of contraction. The role of the endothelium in desensitization was studied using aortic rings with endothelium [E(+)] and with endothelium removed [E(-)]. Maximal phenylephrine (PE)-induced contraction (Emax) for E(+) was 1.7 +/- 0.3 g in controls and 0.4 +/- 0.1 g in PHEO (p less than 0.001), demonstrating desensitization; however, for E(-), Emax was 2.4 +/- 0.2 g in PHEO vs. 2.5 +/- 0.2 g in controls, demonstrating restoration of maximal contraction when the endothelium was removed. However, sensitivity [-log EC50(M)] to PE in E(-) remained significantly lower in PHEO compared to controls (6.94 +/- 0.12 vs. 7.51 +/- 0.14, respectively, p less than 0.001). Similarly, in aortic ring segments desensitized in vitro with phenylephrine, the maximal contraction in phenylephrine-exposed aortas was 60% of that seen in controls. Removal of the endothelium from the vessels pretreated with phenylephrine fully restored the maximal response and sensitivity of these vessels. Treatment of desensitized vessels with hemoglobin (5 x 10(-5) M) restored the maximal contraction and sensitivity to phenylephrine. When the endothelium was removed prior to chronic exposure to phenylephrine, the sensitivity to phenylephrine decreased while the Emax remained similar to controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Responsiveness of peripheral veins to transdermal and sublingual nitroglycerin in healthy male volunteers.

Nitroglycerin (NTG) is a potent vascular smooth muscle relaxant. With the widespread use of transdermal NTG patches for the prophylaxis of angina, two important issues have arisen: (a) the relative efficacy of transdermal NTG patches compared to other formulations of NTG, and (b) the possibility of development of tolerance to transdermal NTG. We have investigated these two issues by studying the effect of systemically administered NTG (transdermal patches, ointment, and sublingual tablets) on alpha-adrenergic receptor agonist-mediated constriction of human dorsal hand veins. Nitroglycerin patches and ointment (15-60 mg/24 h) applied for 1-4 h did not modify the sensitivity (ED50) to the alpha-adrenergic agonist, phenylephrine. However, sublingual NTG (0.15-0.60 mg) administration caused significant relaxation of partially constricted veins. Following exposure for 24 h to a NTG patch (15 mg/24 h), NTG dose-response curves were not altered suggesting there was no development of tolerance to transdermal NTG. We conclude from our observations that tolerance to transdermal NTG does not appear in veins, possibly due to the low plasma NTG concentrations produced by this preparation. Our results also indicate that high doses of transdermal NTG do not modify phenylephrine-mediated constriction of peripheral veins in humans.

Comparison of age-related changes in prostaglandin E1 and beta-adrenergic responsiveness of vascular smooth muscle in adult males.

Aging in humans is associated with a general decline in beta-adrenergic receptor responsiveness. Whether this is a consequence of a defect at the receptor level or along the adenylate cyclase pathway is not known. Using a technique to measure compliance of dorsal hand veins, we investigated the venodilatory response to isoproterenol and prostaglandin E1 (PGE1), which interact with distinct membrane-bound receptors but activate the same adenylate cyclase system. Studies were conducted in 7 young (Y, less than 30 years) and 7 elderly (E, greater than 60 years) healthy male volunteers. Dilatation induced by isoproterenol (mean +/- SD) was 43 +/- 8% in E vs 97 +/- 17% in Y, p = .003. However, PGE, produced complete relaxation in both Y and E subjects (122 +/- 17% vs 97 +/- 19% respectively, p = .270). The sensitivity to PGE1 was not significantly different between the Y and E. Our results demonstrate that PGE1 is a potent venodilator in humans and that the age-related decline in vascular response is specific to beta-adrenoceptor agonists and does not reflect a generalized loss in responsiveness to adenylate cyclase coupled receptors.

Absence of age-related changes in venous responsiveness to nitroglycerin in vivo in humans.

We have previously demonstrated a progressive loss in the ability of the beta-receptor agonist isoproterenol to relax veins with increasing age. In this study the influence of age on the responsiveness of medium-sized veins to local infusions of nitroglycerin was studied in two groups of 15 healthy male volunteers using the dorsal hand vein compliance technique. A dorsal hand vein was preconstricted with submaximally effective doses of phenylephrine and a dose-response curve with nitroglycerin was established. The nitroglycerin dose that caused a 50% venodilation ranged from 0.7 to 22.4 ng/min (geometric mean 3.6 ng/min) in the younger group (aged 19 to 29 years; mean +/- SD 23 +/- 3 years) and from 0.2 to 17.9 ng/min (geometric mean 3.6 ng/min) in the older subjects (aged 50 to 74 years; mean +/- SD 63 +/- 7 years) (P = 0.49 between geometric means). The mean (+/- SD) maximal venodilation, based on the pretreatment baseline, was 103% +/- 65% in the younger and 125% +/- 64% in the older subjects (P = 0.18). These results indicate that there is no age-related change in venous responsiveness to nitroglycerin.

Clonidine and guanfacine in hypertension.

Guanfacine, 1 to 3 mg/day, and clonidine, 0.1 to 0.3 mg twice a day, were compared in a 24-week double-blind, randomized, parallel study of 42 patients with hypertension that was inadequately treated by chlorthalidone, 25 mg/day. Mean reduction of blood pressure was 18/9 mm Hg after guanfacine and 14/8 mm Hg after clonidine. To determine the incidence of rebound hypertension, subjects were hospitalized for 7 days during chlorthalidone therapy for collection of baseline data and once again immediately after abrupt withdrawal of the alpha-agonist after 24 weeks of dosing. Although blood pressure and heart rate rose significantly in both groups, the changes after clonidine withdrawal were greater and occurred earlier (day 2) than those after guanfacine withdrawal (day 4). Forty percent of the subjects receiving guanfacine and 64% of subjects receiving clonidine had diastolic blood pressure elevations greater than or equal to 10 mm Hg from baseline. There were increases in urinary norepinephrine levels in both groups after drug withdrawal, but these correlated poorly with blood pressure rise. Side effects after guanfacine were much the same as those after clonidine. Guanfacine taken once a day provides an effective and safe alternative to clonidine in the management of essential hypertension.