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PubMed1998

Relative maxillary retrusion as a natural consequence of aging: combining skeletal and soft-tissue changes into an integrated model of midfacial aging.

The contribution of maxillary retrusion to the formation of the nasolabial fold is evaluated in the present study. Clinical observation of patients from the craniofacial unit with concomitant maxillary retrusion revealed prominent signs of midfacial aging: specifically these individuals displayed a prominent nasolabial fold at an early age. This observation led to the hypothesis that relative maxillary retrusion occurs as a normal feature of the aging process. Retrusion of the lower facial skeleton below the soft tissue of the nasolabial fold causes the nasolabial fold to appear more prominent. To test this hypothesis, computed tomographic data were assembled retrospectively and included both males and females, young and old. The age range of the males (n = 14) was 18 to 24 years (young) and 43 to 57 years (old); the age range of the females (n = 14) was 15 to 30 years (young) and 43 to 57 years (old). All individuals had complete upper dentition and had no bony facial injury. Computed tomographic data were reconstructed into three-dimensional images, and a technique was developed to create a standardized lateral view which eliminated rotational variance. Analysis of anterior-posterior changes showed that there is a tendency for the lower maxillary skeleton at pyriform to become retrusive with age relative to the upper face in individuals with complete dentition. Findings were very significant for both males and females (p = 0.0001 and p = 0.002, respectively). In both groups, a slight increase in vertical maxillary dimension was noted, consistent with previous studies. It is suggested that relative maxillary retrusion is a factor in the development of the nasolabial fold. The skeletal features of normal midfacial aging can be combined with the soft-tissue features such as ptosis and atrophy into an integrated model of midfacial aging. A model such as this has significance regarding both the timing and choice of procedure used to restore the aging midface.

Adolescent↗
PubMed1996

Coordinating initiatives in critical pathways and information systems.

Health care providers have begun to use critical pathways and order sets to standardize clinical care in order to improve clinical resource management. This article describes ways that critical pathways and order sets can be developed and implemented in a coordinated manner. This approach allows for a process that facilitates automation of critical pathways variance analysis and continuous feedback to clinicians.

Cost Control↗
PubMedDate not supplied

Structural equation modeling for conducting tests of differences in multiple means.

Multivariate methods for analyzing group differences in means on dependent variables include multivariate analysis of variance, discriminant analysis, and multivariate analysis of factor means. To make appropriate choices among these methods, researchers should understand the statistical models underlying them. We present these models using path diagrams within a structural equation modeling framework. Results for the different methods are presented for an example concerning coping with asthma.

Adaptation, Psychological↗
PubMed2003

The risk of death for Jehovah's Witnesses after major trauma.

BACKGROUND: Trauma surgeons are faced with life-threatening blood loss in patients such as Jehovah's Witnesses. We assessed and compared the risks of death after major trauma for Jehovah's Witnesses and other religious groups. METHODS: A retrospective cohort study was conducted between August 1992 and September 1999 in a Level I academic trauma center. Statistical methods included Tukey's one-way analysis of variance, chi2 analysis, and bivariate and multivariate logistic regression analyses. RESULTS: The cohort consisted of 556 patients: 82 Jehovah's Witnesses (14.7%), 52 Baptists (9.4%), 101 Catholics (18.2%), and 321 patients belonging to other religious groups (57.7%). Mean Injury Severity Scores for 433 patients were 10.3 +/- 9, 8.9 +/- 10, 10.3 +/- 11, and 11.3 +/- 14, respectively. There were no significant differences in mean Injury Severity Scores between religious groups, and no statistically significant associations between religion and Injury Severity Scores were identified. Significant predictors of mortality were age, systolic blood pressure at admission, Glasgow Coma Scale score, and type of trauma. Jehovah's Witnesses were 6% more likely to die after major trauma than Baptists, 20% more likely than Catholics, and as likely as patients from any other religious groups. CONCLUSION: After controlling for age, race, systolic blood pressure, Glasgow Coma Scale score, and type of trauma, Jehovah's Witnesses have a nonsignificant increased risk of death after major trauma compared with other religious groups.

Adolescent↗
PubMed1993

Learning needs of persons with epilepsy: a comparison of perceptions of persons with epilepsy, nurses and physicians.

The purpose of this study was to describe and compare patients', nurses' and physicians' perceptions of learning needs of persons with epilepsy. The study is based on adult learning theory which states that learning needs dictate receptivity to information and knowledge of learning needs can help structure teaching sessions. Study participants were recruited from patients attending epilepsy clinics, neuroscience nurses employed at study hospitals or working with neurologists or neurosurgeons and neurologists or neurosurgeons practicing in the state. The sample sizes were: 59 patients, 85 nurses and 38 physicians. Data were analyzed using frequencies, percent and analysis of variance. Data analysis revealed that patients, nurses and physicians similarly ranked major areas of learning needs. However, differences in the ranking of individual learning needs were noted between patients and health care providers. An understanding of the differences and similarities among the groups provides useful information for educational programs for epilepsy patients.

Adult↗
PubMed1983

Fibrinolytic activity in men with acute myocardial infarction before 60 years of age.

Fibrinolytic activity in plasma after venous occlusion was determined on two consecutive days 1-5 years after an acute myocardial infarction sustained before the age of 60 years in a group of 66 non-diabetic men with normal serum cholesterol levels, and in an age- and sex-matched reference group of 32 men. The infarction group was divided into 2 subgroups: one with normal (n = 42), the other with elevated (n = 24) diastolic blood pressure. Variance analysis did not reveal any statistically significant differences in fibrinolytic activity after repeated provocation between the three groups, but in a Student's test the value was significantly lower in the infarction group with high diastolic pressure than in the reference group. A relationship was found between apolipoprotein AI and fibrinolytic activity after repeated provocation.

Blood Pressure↗
PubMed1984

Pencil and paper tests--sensitivity to psychotropic drugs.

The literature on pencil and paper tests and the effects of psychotropic drugs is reviewed. Performance at digit symbol substitution, symbol copying, letter cancellation, arithmetic, logic and cognitive processing with a relatively constant level of triazolam was compared with placebo. Analysis of variance, covariance analysis and principal component analysis were applied to the data. Pencil and paper tests which measure various skills are useful for detecting drug effects. Letter cancellation, arithmetic and DSST appear to be most sensitive, although logic and symbol copying may be useful.

Anti-Anxiety Agents↗
PubMed2005

Superior mobilisation of haematopoietic progenitor cells with glycosylated G-CSF in male but not female unrelated stem cell donors.

Granulocyte colony-stimulating factor (G-CSF) effectively mobilises haematopoietic stem cells to the peripheral blood. It is unclear whether the mobilisation of stem cells with lenograstim (glycosylated G-CSF) or filgrastim (non-glycosylated G-CSF) leads to a higher cell number of collected engraft able progenitor cells. Thus, we investigated harvesting efficiency of the licensed G-CSF preparations in mobilising peripheral stem cells in a randomised study. A total of 501 healthy unrelated donors, including 339 males and 162 females received either lenograstim (n = 261) or filgrastim (n = 240) at 10 microg/kg body weight (BW) per day. Aphaeresis was performed on day 5 and, if necessary, on day 6 of mobilisation. The number of CD34+ cells collected was 11.5% higher in the lenograstim group (7.19 x 10(6) vs. 6.44 x 10(6)/kg BW donor; P < 0.03). Univariate variance analysis revealed that this effect was caused by male donors: more progenitors cells per kg BW of the donor (7.73 x 10(6) vs. 6.88 x 10(6); P < 0.017) and of the recipient (10.1 x 10(6) vs. 8.88 x 10(6), P < 0.029) could be harvested. There was no significant difference in the percentage of donors in whom a second aphaeresis was required (9.6% vs. 11.6%). Lenograstim mobilises progenitor cells into the peripheral blood more effectively in males than filgrastim.

Adult↗
PubMed1993

Lipoprotein lipase activity in muscle tissue influenced by fatness, fat distribution and insulin in obese females.

Obesity is associated with dyslipidaemia and increased morbidity and mortality from premature atherosclerosis and diabetes mellitus. Particularly, hypertriglyceridaemia is a characteristic finding in patients with obesity. In addition, the elevated levels of triglycerides may be an important risk factor for development of the obesity-related complications. Lipoprotein lipase activity in skeletal muscle tissue (mLPL) has previously been found to be an important factor regulating the concentration of serum triglycerides. To describe the relationship between mLPL, triglycerides and fatness/fat distribution in more detail we have investigated these parameters under basal conditions and during insulin stimulation in 20 obese females. During hyperinsulinaemia (204 microU ml-1) for 4 h the mLPL activity decreased from 528 +/- 52 nmol FFA g-1 to 412 +/- 44 (P < 0.001). Basal mLPL was negatively correlated with serum triglycerides (r = -0.48, P < 0.05) and positively correlated with HDL-cholesterol (r = 0.58, P < 0.01). Employing multiple variance analysis it was found that both BMI and WHR were negatively correlated to mLPL, however, the impaired lipid profile (high triglyceride, low HDL-cholesterol, high FFA) could only be related to BMI and not to WHR in these obese females. However, reduced insulin-action (insulin resistance) was closely related to abdominal fatness determined by WHR both in relation to the insulin-effect on mLPL as well as for the insulin-effect on whole-body glucose metabolism (clamp-study).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1989

Behavioural habits and affective disorders in old people.

The purpose of this paper is to explore and detect possible factors associated with the appearance and maintainance of affective disorders in the elderly; special emphasis was put on anxiety and depression. Two hundred and seven Cordobese citizens over 65 years of age, filled in a Hospital Anxiety and Depression Questionnaire and a Habit Behavioural Questionnaire. The variables sex, hospitalization and family life were controlled. The results emphasize the existence of moderate but significant correlations between depression and certain behavioural habits in the elderly, such as: appetite, taking walks and sleeping. The greater the appetite, food intake, taking of frequent walks and hours of sleep, the more the association with lower levels of depression in the elderly studied. Anxiety, on the other hand, only correlates significantly with behavioural habits related to sleep cycles. By means of a unifactorial variance analysis, the differential effect of some of the behavioural habits on the aforementioned disorders is shown. Using a multiple regression analysis, results of the behavioural habits, which seem to be the best predictors of anxiety and depression in the elderly, are obtained. After a discussion of these results, their possible implications in nursing are analysed and a few interesting conclusions are drawn.

Activities of Daily Living↗
PubMed2005

Effect of Tuf-Coat on Feldspathic porcelain materials.

Ion exchange has been shown to increase the fracture strength of not only industrial glasses but also dental porcelains. Tuf-Coat, an ion exchange material, has been introduced as a simple method to strengthen dental porcelain restorations. Our experimental investigation aims to evaluate the effect of the ion exchange (Tuf-Coat) on the flexural strengths of specimens made with Vita VMK 68, Ceramco veneer, IPS and Matchmaker body porcelain. Eighty specimens were fabricated as discs 13 mm in diameter and 2 mm thick according to manufacturers' recommendations. Specimens were tested using a universal testing machine with a crosshead speed of 0.5 mm/min. by a method of biaxial flexural strength test. The results were evaluated using one-way variance analysis and 'Student's t' test to compare results at P < 0.05 level. Among the porcelains tested only Vita VMK 68 has been statistically affected by the ion exchange method Tuf-Coat.

Dental Alloys↗
PubMed1989

The concentration of penicillin in bovine conjunctival sac fluid as it pertains to the treatment of Moraxella bovis infection. (I) Subconjunctival injection.

Single dose, subconjunctival injections of procaine penicillin using either skin or conjunctival routes of administration were evaluated in order to compare the duration of antibacterial concentrations at the site of Moraxella bovis infection. Samples of conjunctival sac fluid (CF) were collected using blunted capillary tubes and were periodically assayed for penicillin by an agar-well-diffusion technique. Linear regression lines were constructed for concentration of penicillin-time profiles. Similarity of the regression slopes for each treatment enabled the construction of three common lines by the method of co-variance analysis in order to represent each treatment. Treatments were thereafter compared by the slopes of the common regression lines. A subconjunctival injection of procaine penicillin at a dose of 6 X 10(5) iu in 2 ml, administered either through the skin or through the conjunctiva, produced a peak penicillin concentration in the CF of approximately 8 iu/ml for either route and a duration of therapeutic concentration (DTC) of 67.6 +/- 4.9 and 40 +/- 2.7 h respectively. A dose of 3 X 10(5) iu in 1 ml, administered through the conjunctiva, produced a similar peak but the DTC was reduced to 35 +/- 4.2 h. The results of this study support field practices, as adequate penicillin concentrations were maintained by both techniques investigated.

Animals↗
PubMed1989

The concentration of penicillin in bovine conjunctival sac fluid as it pertains to the treatment of Moraxella bovis infection. (II) Topical application.

Sodium benzyl penicillin, procaine penicillin and benethamine penicillin were applied into the bovine conjunctival sac as an aqueous solution or in ointment form in order to study the concentration-time profiles. The series of treatments was repeated in five animals in a random sequence. Penicillin concentration in conjunctival sac fluid (CF) was determined using the agar-well-diffusion assay technique. The data obtained were transformed to linear regression slopes. Similarity of the slopes within treatments (in five different eyes) enabled the construction of four common lines by co-variance analysis to represent each treatment. The regression coefficients of the four common lines were then compared to study the difference between treatments. Topical application of 5,000 iu sodium benzylpenicillin in aqueous solution at a concentration isotonic with 0.9% saline, produced a duration of therapeutic concentration (DTC) in CF of 12.6 +/- 1.5 h. When the same salt or other less water-soluble ones were formulated at the same concentration in an ointment base, the DTC was significantly prolonged. For all treatments, peak concentrations in CF were recorded at the first sampling and ranged between 7 iu/ml and 14 iu/ml. Sodium benzylpenicillin or procaine penicillin, both in the ointment base, produced DTCs of 38.8 +/- 2.1 h and 37 +/- 4.0 h, respectively, while the ointment formulation of benethamine penicillin produced a DTC of 56 +/- 4.5 h. The prolonged duration observed in the eye ointments can be partly accounted for by the viscous nature of the base. Other differences may be dependent on relative water solubility of each penicillin product and complexity of the surface mucosae of the eye.

Administration, Topical↗
PubMed2006

Genetic similarity of hepatitis C virus and fibrosis progression in chronic and recurrent infection after liver transplantation.

The effect of hepatitis C virus (HCV) genetic heterogeneity on clinical features of post-transplantation hepatitis C is controversial. Different regions of the HCV genome have been associated with apoptosis, fibrosis, and other pathways leading to liver damage in chronic HCV infection. Besides, differences in immunodominant regions, such as NS3, may influence HCV-specific immune responses and disease outcome. In the liver transplant setting, a recent study has reported a positive association between HCV-1b Core region genetic relatedness 5-year post-transplantation and histological severity of recurrent hepatitis C. We have compared nucleotide sequences of HCV Core, NS3 and NS5b regions in HCV-1b-infected patients 3 years post-transplantation (n = 22). A cohort of nontransplanted patients (n = 22) was used as control of natural chronic HCV-1b infection. Histological evaluation was used to define the rate of fibrosis progression. Molecular variance analysis did not show significant differences in HCV sequences between transplanted and nontransplanted patients, or between those with fast or slow fibrosis progression. The same results were obtained when analysing phylogenetic trees for Core, NS3 and NS5b regions. A more appropriate clustering method (using minimum spanning networks) revealed a significant positive relationship between HCV genetic similarity in Core (r = 0.550, P < 0.01) and NS5b regions (r = 0.847, P < 0.01) and the yearly rate of fibrosis progression in nontransplanted patients which, in contrast, was not observed in transplanted patients. Our results indicate that some strains of HCV-1b might be more pathogenic in the natural course of chronic infection by this virus subtype. In the liver transplant setting, when the immune response is severely compromised, other mechanisms are probably more important in determining hepatitis C progression.

Biopsy↗
PubMed1997

Control of rat GluR6 glutamate receptor open probability by protein kinase A and calcineurin.

1. We have used non-stationary variance analysis to examine the single channel conductance and the probability of channel opening at the peak of the homomeric GluR6 response (Po,peak) to 100-200 ms application (10-90% exchange time, 0.3 ms) of glutamate onto excised membrane patches from transiently transfected human embryonic kidney cells (HEK 293). 2. Our determinations of both Po,peak and single channel conductance of simulated current responses are insensitive to system filtering, response rise time, desensitization rate and measured variation in our drug perfusion speed. Isolation of stochastic current fluctuations using the local mean response waveform minimizes problems associated with modest rundown of response amplitude during the experiment. 3. The slope conductance calculated from the weighted mean unitary currents for the channels activated in response to glutamate application is 16 pS. Chord conductance between-40 and -80 mV is independent of agonist concentration. Conversion of the codon for glutamine621 to arginine (Q621R) by RNA editing reduces conductance by more than 35-fold to less than 0.4 pS without changing response time course, desensitization, or Po,peak. 4. Po,peak is high at saturating glutamate concentrations (0.65 +/- 0.23; mean +/- S.D.) and varies with agonist concentrations. The half-maximally effective glutamate concentration (EC50) determined for Po,peak (0.2 mM; Hill slope = 0.6) is similar to that determined for the macroscopic peak current amplitude (0.5 mM; Hill slope = 1.0) in response to rapid agonist application. 5. Inclusion of the purified catalytic subunit of cAMP-dependent protein kinase A (PKA) in the patch pipette increases Po,peak to 0.85 +/- 0.12 and co-transfection of cells with a cDNA encoding the catalytic subunit of PKA (C alpha-PKA) increases Po,peak to 0.94 +/- 0.09. 6. Inclusion of purified calcineurin plus its coactivators 200 nM Ca2+ and calmodulin in the patch pipette decreases Po,peak to 0.48 +/- 0.10. The calcineurin-stimulated decrease of Po,peak in cells co-transfected with C alpha-PKA is blocked by 800 nM deltamethrin, a calcineurin inhibitor. Calmodulin, 200 nM Ca2+ and deltamethrin have no effect on Po,peak in the absence of calcineurin. As predicted from its effects on Po,peak, inclusion of calcineurin in the patch pipette accelerates the run-down of whole cell GluR6 responses in cells co-transfected with C alpha-PKA. 7. The effects of both calcineurin and PKA on Po,peak for GluR6 receptors in excised patches occur without any detectable changes to response time course, desensitization, or chord conductance. 8. We conclude that the binding of glutamate to homomeric GluR6 receptors is associated with a high probability of channel opening, which is under the control of two signalling systems that are known to be co-localized at the neuronal membrane: PKA (Po,peak near 1.0) and calcineurin (Po,peak near 0.5).

Animals↗
PubMed1998

Autaptic inhibitory currents recorded from interneurones in rat cerebellar slices.

1. While the presence of autapses in the brain is indicated by a large body of morphological evidence, the functional role of these structures has remained unclear. To probe for autaptic currents, we have recorded current responses following short somatic depolarizing pulses in Cl--loaded interneurones (stellate and basket cells) from rat cerebellar slices (animals aged 27-39 days). 2. In approximately 20 % of the recordings, fluctuating inward current transients were obtained with a latency of 1.15-2.45 ms (measured from the peak of the depolarization-induced Na+ current; n = 10). 3. These transients were blocked by bicuculline and were sensitive to the extracellular Ca2+ concentration. 4. Assuming low release probability, as suggested by the high failure rate (0.65-0.92, n = 10), quantal sizes ranging from 21 to 178 pA (-70 mV; n = 10) were calculated from a variance analysis of autaptic current amplitudes. 5. We conclude that approximately 20 % of interneurones have a functional autapse. Autaptic currents may inhibit firing of interneurones during high frequency discharges.

Animals↗
PubMed2000

Structural domains of the human GABAA receptor 3 subunit involved in the actions of pentobarbital.

This study was conducted to search for the residues of the beta3 subunit which affect pentobarbital action on the gamma-aminobutyric acid type A (GABAA) receptor. Three chimeras were constructed by joining the GABAA receptor beta3 subunit to the rho1 subunit. For each chimera, the N-terminal sequence was derived from the beta3 subunit and the C-terminal sequence from the rho1 subunit, with junctions located between the membrane-spanning regions M2 and M3, in the middle of M2, or in M1, respectively. In receptors obtained by the coexpression of alpha1 with the chimeric subunits, in contrast with those obtained by the coexpression of alpha1 and beta3, pentobarbital exhibited lower potentiation of GABA-evoked responses, and in the direct gating of Cl- currents, an increase in the EC50 together with a marked decrease in the relative maximal efficacy compared with that of GABA. Estimates of the channel opening probability through variance analysis and single-channel recordings of one chimeric subunit showed that the reduced relative efficacy for gating largely resulted from an increase in gating by GABA, with little change in efficacy of pentobarbital. A fit of the time course of the response by the predictions of a class of reaction schemes is consistent with the conclusion that the change in the concentration dependence of activation by pentobarbital is due to a change in pentobarbital affinity for the receptor. Therefore, the data suggest that residues of the beta3 subunit involved in pentobarbital binding to GABAA receptors are located downstream from the middle of the M2 region.

Animals↗
PubMed2001

Rapidly inactivating and non-inactivating calcium-activated potassium currents in frog saccular hair cells.

1. Using a semi-intact epithelial preparation we examined the Ca(2+)-activated K(+) (K(Ca)) currents of frog (Rana pipiens) saccular hair cells. After blocking voltage-dependent K(+) (K(V)) currents with 4-aminopyridine (4-AP) an outward current containing inactivating (I(transient)) and non-inactivating (I(steady)) components remained. 2. The contribution of each varied greatly from cell to cell, with I(transient) contributing from 14 to 90 % of the total outward current. Inactivation of I(transient) was rapid (tau approximately 2-3 ms) and occurred within the physiological range of membrane potentials (V(1/2) = -63 mV). Recovery from inactivation was also rapid (tau approximately 10 ms). 3. Suppression of both I(transient) and I(steady) by depolarizations that approached the Ca(2+) equilibrium potential and by treatments that blocked Ca(2+) influx (application Ca(2+)-free saline or Cd(2+)), suggest both are Ca(2+) dependent. Both were blocked by iberiotoxin, a specific blocker of large-conductance K(Ca) channels (BK), but not by apamin, a specific blocker of small-conductance K(Ca) channels. 4. Ensemble-variance analysis showed that I(transient) and I(steady) flow through two distinct populations of channels, both of which have a large single-channel conductance (~100 pS in non-symmetrical conditions). Together, these data indicate that both I(transient) and I(steady) are carried through BK channels, one of which undergoes rapid inactivation while the other does not. 5. Inactivation of I(transient) could be removed by extracellular papain and could later be restored by intracellular application of the 'ball' domain of the auxiliary subunit (beta2) thought to mediate BK channel inactivation in rat chromaffin cells. We hypothesize that I(transient) results from the association of a similar beta subunit with some of the BK channels and that papain removes inactivation by cleaving extracellular sites required for this association.

4-Aminopyridine↗