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Biomedical subjects

M Wong

Publications and source records attributed to M Wong.

At least 217 records · Page 12Linked to original sources

Self-care instructions: do patients understand educational materials?

As health care providers we are not in a position to teach reading. We do, however, have a legal and an ethical obligation to provide patients with self-care instructions they can understand. Because the methods presented for enhancing patient understanding of self-care instructions are relatively new, and because nurses are just beginning to be aware of the need for such interventions, it will be a while before the ideal situation exists. Ideally, each pamphlet or set of instructions would be coded with the reading grade level needed to understand it and each patient's reading level would be recorded in the chart. Under such "perfect" circumstances it would be easy for nurses to provide patients with instructions at the appropriate reading level. For now, any step that nurses take toward making self-care a reality for patients who read poorly is a step in the right direction. People with poor reading skills are less adept at formulating questions than good readers because they lack vocabulary and the ability to analyze written material. Rather than be regarded as stupid, many choose not to verbalize their lack of understanding. This phenomenon puts a large group of patients at risk for health complications related to inadequate understanding of self-care directions.

Adult↗

A comparison of enalapril with hydralazine-isosorbide dinitrate in the treatment of chronic congestive heart failure.

BACKGROUND: To define better the efficacy of vasodilator therapy in the treatment of chronic congestive heart failure, we compared the effects of hydralazine and isosorbide dinitrate with those of enalapril in 804 men receiving digoxin and diuretic therapy for heart failure. The patients were randomly assigned in a double-blind manner to receive 20 mg of enalapril daily or 300 mg of hydralazine plus 160 mg of isosorbide dinitrate daily. The latter regimen was identical to that used with a similar patient population in the effective-treatment arm of our previous Vasodilator-Heart Failure Trial. RESULTS: Mortality after two years was significantly lower in the enalapril arm (18 percent) than in the hydralazine-isosorbide dinitrate arm (25 percent) (P = 0.016; reduction in mortality, 28.0 percent), and overall mortality tended to be lower (P = 0.08). The lower mortality in the enalapril arm was attributable to a reduction in the incidence of sudden death, and this beneficial effect was more prominent in patients with less severe symptoms (New York Heart Association class I or II). In contrast, body oxygen consumption at peak exercise was increased only by hydralazine-isosorbide dinitrate treatment (P less than 0.05), and left ventricular ejection fraction, which increased with both regimens during the 2 years after randomization, increased more (P less than 0.05) during the first 13 weeks in the hydralazine-isosorbide dinitrate group. CONCLUSIONS: The similar two-year mortality in the hydralazine-isosorbide dinitrate arms in our previous Vasodilator-Heart Failure Trial (26 percent) and in the present trial (25 percent), as compared with that in the placebo arm in the previous trial, (34 percent) and the further survival benefit with enalapril in the present trial (18 percent) strengthen the conclusion that vasodilator therapy should be included in the standard treatment for heart failure. The different effects of the two regimens (enalapril and hydralazine-isosorbide dinitrate) on mortality and physiologic end points suggest that the profile of effects might be enhanced if the regimens were used in combination.

Adolescent↗

Electrophysiological evidence for a rapid membrane action of the gonadal steroid, 17 beta-estradiol, on CA1 pyramidal neurons of the rat hippocampus.

The rapid electrophysiological effects of 17 beta-estradiol on CA1 pyramidal neurons (n = 86) were investigated utilizing intracellular recording from the rat hippocampal slice preparation. Bath application of 17 beta-estradiol, but not 17 alpha-estradiol, caused a reversible depolarization and increased input resistance with a latency of less than 1 min in 19.8% of CA1 neurons tested. There was no significant difference in the percentage of estradiol-responsive cells between male and female rats. Estradiol-responsive cells were identified from prepubertal female rats, as well as females in all stages of the estrous cycle. 17 beta-estradiol had no effect on the slow afterhyperpolarization or accommodative properties of CA1 neurons. In 2 out of 4 cells tested, the specific antiestrogen, tamoxifen, blocked the excitatory response to 17 beta-estradiol.

Animals↗

Effects of indomethacin, triamcinolone, and dexamethasone on recombinant human interleukin-1-induced substance P and prostaglandin E2 levels in rabbit knee joints.

Intra-articular (i.a.) injection of recombinant human interleukin-1 alpha (rHuIL-1 alpha) in rabbit knees induced both an inflammation, as determined by increases in leukocytes in the joint fluid, and cartilage degradation, as measured by loss of proteoglycan. Substance P (SP) and prostaglandin E2 (PGE2) levels in the joint lavage are also elevated. Treatment with 5 mg indomethacin/kg, p.o., b.i.d., 2 mg triamcinolone i.a., and 10 mg dexamethasone/kg, p.o., reduced synovial lavage leukocyte counts, as well as PGE2 and SP lavage concentrations induced with IL-1 injection. However, none of the treatments inhibited rHuIL-1-induced proteoglycan loss.

Animals↗

Interleukin-1-induced cartilage degradation is independent of substance P level in rabbit knees.

The effect of SP on recombinant human IL-1 alpha-induced cartilage degradation in rabbit knees was investigated. Co-injection of 10 ng IL-1 and 1 micrograms SP did not increase cartilage degradation above the level observed after injection of 10 ng IL-1 alone. Co-injection of 100 ng IL-1 and 150 micrograms Spantide, a potent SP antagonist, did not reduce the level of cartilage degradation. Infusion of 100 ng SP/day for two weeks did not induce cartilage degradation. These observations suggest that cartilage degradation induced by IL-1 is independent of SP concentrations in rabbit knees.

Animals↗

Effect of capsaicin on carrageenan-induced inflammation in rat pleurisy and exudate substance P level.

Injection of 2.5 mg of lambda-carrageenan into the rat pleural cavity resulted in a time-dependent increase in pleural exudate substance P (SP) levels up to 24 hr. Synergistic increases in the exudate formation were observed when a sub-optimal quantity of carrageenan was injected with SP. Pre-treatment of rats with capsaicin at 50 and 100 mg/kg s.c. daily for one week prior to the induction of pleurisy blocked the increase in exudate volume and SP levels when compared to that normally detected after carrageenan injection. These results suggest that inhibition of SP production may improve inflammatory conditions.

Animals↗

Musculoskeletal ontogeny, phylogeny, and functional adaptation.

Physical forces applied to connective tissues may cause significant changes in cell metabolism and gene expression. Theoretical investigations indicate that mechanical loading histories beginning very early in skeletal development may guide endochondral ossification patterns and the initial architectural construction of bones. Developmental patterns and structures of bones can be emulated using mathematical algorithms or "rules of construction" which relate developmental processes to tissue stress (or strain) histories. Skeletal forms and tissues are well-designed for their mechanical function primarily because their histomorphological construction has been guided by mechanical loading during growth and development. Construction rules of developmental mechanics can also be used to describe many of the histological and morphological adaptations of mature skeletal tissues to changes in customary physical activity. Over many generations, changes in the heritable genetic information occurs by mutation and genetic variability. The range of skeletal forms that are possible in evolution due to such variations, however, is constrained by the developmental rules of construction that reflect biophysical processes associated with the tissue mechanical loading.

Adaptation, Physiological↗

Characterization of Xenopus laevis proenkephalin gene.

Enkephalins are opiate peptides found in a variety of tissues including brain and pituitary. In brain, they function as neurotransmitters, neuromodulators and neurohormones. Recent studies show that proenkephalin mRNA is expressed early in development both in mammals and the amphibian, suggesting that enkephalins may play a unique role in embryogenesis. In order to characterize factors which regulate the onset and patterning of expression of this gene in adult and developing frog embryos, the proenkephalin A gene was cloned from Xenopus laevis. The clones have been characterized by DNA sequencing and restriction endonuclease mapping. The gene is made up of three exons which span approximately 12 kb. Exon I encodes the 5' untranslated region of the mRNA. Exon II contains the signal peptide and the N terminus of the mature protein. Biologically active opioid peptides are generated from exon III. Comparison to mammalian proenkephalin genomic sequence indicated that nucleotide sequences of the 5' flanking region, noncoding exon I and exon II were not well conserved but exon III was highly conserved. Primer extension and RNase protection assay analyses of the RNA transcripts revealed two major 5' ends. The putative TATA box, CAAT box, CRE and Pit 1 elements have been identified on this gene by sequence homology to published consensus sequences. To assay for sequences that could potentially regulate Xenopus proenkephalin expression, we transfected constructs that contained upstream genomic sequences linked to the CAT reporter gene into various eukaryotic cell lines. The expression of the fusion gene constructs were detected and could be induced 10- to 30-fold upon treatment with forskolin.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

A clinical comparison of treatments for endemic dental fluorosis.

A case report is presented describing the treatment for endemic dental fluorosis. Six maxillary anterior teeth were treated, three with an acid-bleach combination technique and three with an acid technique. No clinical differences was noted in treatment time or esthetic results.

Acid Etching, Dental↗

Four root canals in a mandibular second premolar.

A case report is presented involving the successful endodontic treatment of a mandibular second premolar with four canals in a single root. Statistics of morphological variations are irrelevant when the involved tooth is an anomaly.

Adult↗

Surgical fenestration of large periapical lesions.

The decompression technique utilizing tubing for the treatment of large periapical lesions has been widely used with success. However, unobtainable biopsies and patient noncompliance are among the disadvantages that are of concern. An alternative approach is presented, whereby a surgical procedure is performed involving only partial removal of tissue from the lesion. The advantages of this procedure are discussed.

Adult↗

Maxillary first molar with three palatal canals.

A case report is presented involving the endodontic treatment of a maxillary first molar with an unusual morphological variation of the palatal root. The palatal root canal system was characterized by a single canal orifice, a trifurcation on the apical one third of the root and three separate foramina.

Adult↗

Vital bleach of hemorrhagic discoloration.

An unusual case is presented of a maxillary central incisor with hemorrhagic discoloration that was successfully treated with the thermocatalytic vital bleach technique. This case emphasizes the need for a thorough radiographic and clinical examination to include vitality tests when a patient presents with a discolored tooth.

Adult↗

Intracoronal isolating barriers: effect of location on root leakage and effectiveness of bleaching agents.

The purpose of this study was to evaluate the ability of several intracoronal isolating barrier materials to prevent leakage of a bleaching agent into the roots of teeth and to determine whether placement of the barrier material at the cementoenamel junction or below the cementoenamel junction has an effect on the bleaching results of the crowns. Fifty teeth were stained in vitro, and gutta-percha fillings were placed in the root canals. The experimental isolating barriers were placed at the cementoenamel junction or 2 mm below the cementoenamel junction. A walking bleach of Superoxol and sodium perborate was placed in the pulp chamber for three treatments. The roots of the teeth were evaluated for the presence of root decoloration, and the crowns of the teeth were evaluated for bleaching effect. Findings from this study showed a significant difference between gutta-percha alone and gutta-percha with barrier in preventing root decoloration (p less than 0.05). No significant differences were found between the other experimental groups in preventing root decoloration. Placement of an intracoronal isolating barrier material 2 mm below the cementoenamel junction resulted in a more acceptable esthetic bleaching result of the crowns than did placement of barrier material at the cementoenamel junction.

Dental Leakage↗

Treatment considerations in a geminated maxillary lateral incisor.

A patient with anomalous maxillary lateral incisor was referred for endodontic therapy. A diagnosis of irreversible pulpitis of a geminated maxillary lateral incisor was made. The preoperative radiograph revealed an image of a single root canal but in fact the tooth had two separate and distinct root canals. Treatment considerations of this anomaly are discussed.

Adult↗

A comparison of anxiety levels associated with root canal therapy and oral surgery treatment.

Questionnaires regarding experience, hearsay, and perceptions of anxiety toward eight dental treatments were distributed to a general patient population. Data revealed that among 349 respondents 35% heard that root canal therapy was the most unpleasant dental treatment, whereas 29% listed oral surgery treatment as having the worst reputation. However, 53% of those experiencing oral surgery treatment stated that an oral surgery treatment was the most unpleasant treatment whereas only 17% experiencing root canal therapy stated the same for root canal therapy. On the basis of anxiety scores, root canal therapy and oral surgery treatment were categorized in the high-anxiety category, crowns, dentures, and fillings in the moderate-anxiety category, and cleaning, sick call, and examination in the low-anxiety category. The anxiety levels of root canal therapy and oral surgery treatment were then analyzed as they related to different experience groups (combinations of root canal therapy and oral surgery and experience), hearsay experience, and most unpleasant experience with root canal therapy and oral surgery. Patients having experience with root canal therapy or oral surgery treatment had lower anxiety levels toward these respective treatments than did those who had no such experience. Patients who have heard negative stories (hearsay) of root canal therapy and oral surgery showed higher levels of anxiety toward these respective treatments than did those who have not heard such stories. But former endodontic patients who had heard negative stories about root canal therapy actually recorded lower anxiety levels toward root canal therapy than those patients with no negative hearsay experience.(ABSTRACT TRUNCATED AT 250 WORDS)

Dental Anxiety↗

Opiate agonists activate feeding in Limax: comparison of in vivo and in vitro effects.

The neural control system for feeding in the terrestrial mollusc Limax maximus is modulated by at least two major families of peptides. Sequence homology between one of the peptides known to modulate Limax feeding and some members of the opioid peptide family suggested that opioid peptides might also modulate Limax feeding. Experiments with the mu agonist morphine and the kappa agonist U50,488H showed that the probability of feeding, but not meal size, was increased by morphine injection into intact animals, whereas the length of feeding motor program responses elicited from the isolated lip-brain preparation of Limax was augmented by U50,488H. The behavioral effect of morphine was blocked by naltrexone injection, whereas the physiological effect of U50,488H was blocked by naloxone. Factors that influence the behavioral and electrophysiological effects of opioids on mollusc feeding are discussed.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

Selective cytotoxicity of N-acetyl-4-S-cysteaminylphenol on follicular melanocytes of black mice.

Previous in vivo studies have shown that 4-S-cysteaminylphenol (4-S-CAP) and N-acetyl-4-S-cysteaminylphenol (N-Ac-4-S-CAP) have antimelanoma effects and that N-Ac-4-S-CAP produced a 98% depigmentation of hair follicles of black mice. This study investigated the process of selective melanocytotoxicity by N-Ac-4-S-CAP through light and electron microscopy studies of hair follicles obtained from newborn black mice treated with N-Ac-4-S-CAP. Visible changes in follicular melanocytes were found 4 h after intraperitoneal (i.p.) administration. Clumps of melanin granules and areas of melanocytic nuclear condensation were seen in the hair follicles. On electron microscopy there was progressive destruction of melanocytes with swelling of membranous organelles, nuclear condensation, and vacuolation of the cytoplasm, culminating in completely necrotic cells. None of these changes were demonstrated in the surrounding keratinocytes. N-Ac-4-S-CAP appears to have specific, cytotoxic effects on melanocytes actively producing eumelanin. The drug may not affect precursor or dormant melanocytes which retain the ability to become active, melanin-producing cells.

Animals↗