Advances in the assessment of self-determination: internal structure of a scale for people with intellectual disabilities aged 11 to 40

BACKGROUND

Advances in theoretical frameworks of self-determination require the development of new assessment instruments. This study examines the dimensional structure of a self-determination scale and analyses the factorial invariance of its measurement across age and gender.

METHOD

The AUTODDIS Scale was used to assess the self-determination of 541 people with intellectual disabilities aged from 11 to 40.

RESULTS

Different models (correlational and hierarchical structures) of the scale were tested. The correlational model obtained from the exploratory structural equation model approach provided the best fit for the data. The results also supported measurement invariance across youths (aged 11 to 21 years) and adults (aged 21 to 40 years) and across genders.

CONCLUSIONS

This study contributes to international research on self-determination and the development of assessment tools in this field, offering a better understanding of this multifaceted and complex construct. The results provide construct validity evidence regarding a new measurement tool tested across people aged 11 to 40, using information from third parties. However, further research is needed to explore the best ways to understand and assess the different factors related to self-determination.

Operationalisation of quality of life for adults with severe disabilities

BACKGROUND

The operationalisation of quality of life for people with more severe disabilities has been acknowledged in the published research for more than two decades. This study aims to contribute to our knowledge and understanding of the quality of life of adults with severe disabilities by developing a set of quality of life indicators appropriate to this population using a Delphi method and the eight-domain conceptual model proposed by Schalock & Verdugo (2002).

METHOD

The participating panel in the Delphi method included 12 experts who evaluated each proposed item according to four criteria: suitability, importance, observability and sensitivity. Descriptive analyses were used to select the best items in each of the four rounds of this Delphi study, as well as examining the coefficients of concordance that were calculated for the final pool of items.

RESULTS

The four rounds of the Delphi study resulted in a final pool of 118 items (91 that were considered valid in the first round plus 27 items proposed, reformulated or discussed in the following rounds). Importance and sensitivity were the criteria that received the highest and lowest ratings, respectively, but also the ones that had the highest and lowest mean coefficients of concordance. Experts showed the strongest agreement for items related to material well-being, while the weakest was found for items related to personal development.

CONCLUSIONS

This study further contributes to our understanding of how to operationalise and measure quality of life in adults with severe disabilities. The item pool generated may prove helpful in the development of instruments for the measurement of quality of life-related outcomes in this population.

The concept of quality of life and its role in enhancing human rights in the field of intellectual disability

BACKGROUND

The changed societal views of persons with disabilities are reflected in the 2006 United Nations Convention on the Rights of Persons with Disabilities. However, what is not specified in the Convention is how to operationalise and measure the Articles composing the Convention, and how to use that information to further enhance the human rights of persons with disabilities.

METHOD

The authors analyse the relationships between eight core quality of life domains and the 34 Articles contained in the Convention.

RESULTS

There is a close relationship between the core quality of life domains and the 34 Articles contained in the Convention. Furthermore, the current status of these Articles can be evaluated through the assessment of indicators associated with the eight core quality of life domains.

CONCLUSIONS

Based on the assessment of these quality of life-related outcomes, three strategies can be used to enhance the human rights of persons with intellectual disability. These three are to employ person-centred planning, publish provider profiles and implement a system of support.

Cholinergic facilitation of erection and ejaculation in spinal cord-transected rats

Penile reflexes (PRs) were monitored in chronic spinal cord-transected rats by identifying them visually, and at the same time they were recorded as the electromyographic activity of bulbospongiosus muscles. Intraperitoneal injection of the agonist muscarine (10 microg) produced a facilitation of PRs. A decrease in the latency, an increase in the number of clusters and often an increase in the duration of cups were found after muscarine. In addition, 66% (six out of nine) of the animals ejaculated after muscarine. These results suggest that cholinergic receptor stimulation may be involved in erectile and ejaculatory mechanisms mediated by the spinal cord.

Muscarinic mediation of the urethro genital reflex in spinal cord-transected rats

The effects of muscarinic receptor stimulation were tested on the urethro genital reflex (UGR) in anesthetized and spinal cord-transected rats. Drugs were applied directly to the spinal cord. The electromyographic activity (EMG) of the bulbospongiosus (BS) muscle was used for recording UGR. In six animals BS as well as soleus, posterior biceps or peroneus tertius muscle EMG was recorded simultaneously. Muscarine (5, 10, 20, 50 and 100 microg) was applied in 22 animals after cutting L6-S1 dorsal roots. Some observations were made on another six animals, to which an extensive bilateral dorsal rhizotomy (L3-S2) was performed. Rhythmic bursts of similar frequency and size to those seen during UGR were found in BS muscle a few minutes after muscarine application. No rhythmic bursting was found on the hindlimb muscles, but exclusively on BS muscles. The effects of homatropine (25, 50, 100 and 200 microg), an acetylcholine muscarinic receptor antagonist, were tested in 21 rats after UGR was elicited three times at low stimulation intensity (7 mm Hg). Homatropine produced two effects: (i) A significant increase in the latency of UGR. (ii) A facilitation of UGR inhibition. In view of these results it can be speculated that muscarinic receptor stimulation is involved in the elicitation of UGR.

Cardiovascular responses to vaginocervical stimulation in the spinal cord-transected rat

The present study ascertained whether increases in heart rate (HR) and systolic blood pressure (SBP) produced by vaginocervical stimulation (VS; 500 g force) persist in the unanesthetized rat after chronic spinal cord transection at selected levels. Three groups were used: spinal cord transection at T7 (n = 10) or L5 (n = 10) or a sham-operated control group (Sh, n = 10). In the Sh group, VS increased significantly both HR, by 95 +/- 14.3 beats/min (bpm) (22 +/- 3.7% above baseline), and BP, by 37 +/- 5.7 mmHg (37 +/- 7.7% above baseline), confirming earlier findings. In the T7 group, VS significantly decreased HR by 107 +/- 21.4 bpm (27 +/- 4.1% below baseline) and increased BP by 41.3 +/- 12.9 mmHg (32 +/- 8.3% above baseline). In response to VS, HR increased in every rat in the Sh group and decreased in every rat in the T7 group. In the L5 group, VS failed to significantly affect HR or BP. In the present study, specific levels of spinal cord transection produced differential HR and BP responses to VS in the rat. A model is presented addressing the component responses of autonomic dysreflexia that can occur, contingent on the level of spinal cord injury, in women during parturition or sexual intercourse.

Immunogenicity of the recombinant SAPA protein of Trypanosoma cruzi for mice

The humoral and cellular immune responses induced by the recombinant SAPA (shed acute phase antigen) of Trypanosoma cruzi were studied in mice and correlated with the immunologic control of parasitemia. The immunizing schedule used consisted of 2 weekly injections of 50 micrograms glutathione-S-transferase (GST)-SAPA in Freund's adjuvant. Specific alpha GST-SAPA antibodies were detected by enzyme-linked immunosorbent assay 1 wk after each antigen dose, the concentration of antibodies after the second injection being 30-fold higher than after the first. Immediate- (ITH) and delayed-type hypersensitivity (DTH) reactions were observed as footpad swelling after injecting 50 micrograms GST-SAPA in preimmunized mice as compared to naive controls. Adoptive transfer experiments indicated that these cutaneous reactions were mediated by lymphoid cells and not by serum. Both humoral and cellular responses were specific for the GST-SAPA antigen and did not cross-react with either the GST or the recombinant GST-1 T. cruzi antigen. Immunized mice that had developed high levels of antibody and DTH reaction to GST-SAPA were able to control the level of parasitemia after challenge with 10(3) blood trypomastigotes. The levels of parasitemia obtained were lowered to about 1/3 (P < 0.05) and mortality at day 60 was reduced from 67 to 25% (P = 0.085). Comparison of this immunizing method with other schedules involving more injections or higher antigen doses indicates that control of parasitemia can be obtained with low amounts of antigen and seems to be associated with the development of DTH.

Neural mechanisms accounting for the increase in blood pressure and heart rate during vagino-cervical stimulation

The rise in blood pressure and heart rate produced by the mechanical stimulation of the uterine cervix (VS) was examined after adrenalectomy, after pelvic or hypogastric neurectomies or after spinal cord transection in anesthetized rats. Neither adrenalectomy, nor hypogastric neurectomy prevented the rise in heart rate and blood pressure produced by VS. After the spinal cord transection at T6 level, VS was still able to produce the rise in blood pressure. However, the rise in blood pressure was significantly lower than that produced in the same animals before the transection. No changes in heart rate were produced by VS after spinal cord transection. This result can be explained because this level of transection prevents the reach of the afferent inflow to the superior cervical ganglia. Pelvic neurectomy abolished completely the effects of VS on blood pressure and heart rate. Low intensity (1-2 times the threshold) electrical stimulation of the pelvic nerve produced a rise in blood pressure. Even though heart rate increased during electrical stimulation, the change in heart rate was not statistically different from the pre-stimulation value. These results suggest that the changes in blood pressure and heart rate produced by VS represent a neuronal reflex response mediated by the pelvic nerve. The fact that the effects of VS on blood pressure persist in spinal cord-transected animals suggests that the reflex is integrated at the spinal level. However, the cardiovascular responses to VS were significantly lower than before transection, suggesting that supraspinal centers are also involved in the reflex.

Vagotomy blocks responses to vaginocervical stimulation after genitospinal neurectomy in rats

To ascertain whether any effects of vaginocervical stimulation (VS) are mediated by the vagus nerve, all known afferent nerves from the reproductive tract to the spinal cord were transected and the rats were tested for residual responses to VS. After combined bilateral transection of the pelvic, hypogastric, and pudendal nerves (NX), the following responses to VS were greatly reduced or abolished: lordosis to flank-perineum palpation, leg extension, immobilization, and blockage of both tail withdrawal to radiant heat and leg withdrawal to foot pinch. However, after these nerve cuts, the following persisted as significant residual responses to VS: 1) analgesia [measured as increase in vocalization threshold (VOCT) to tailshock], 2) pupil dilatation (PD), and 3) increase in heart rate (HR). Subsequent bilateral subdiaphragmatic vagotomy (VX) significantly reduced the magnitude of PD and abolished the analgesia. By contrast, VX produced no significant effect on the HR increase to VS. The above findings provide evidence that brain-mediated responses to vaginocervical stimulation can be elicited via the vagus nerves.

Brain-mediated responses to vaginocervical stimulation in spinal cord-transected rats: role of the vagus nerves

The present study was designed to ascertain whether the vagus nerves convey functional sensory activity from the reproductive tract in rats. Previously, vaginocervical mechanostimulation (VS) was shown to increase pupil diameter (PD) and the threshold of vocalization to tail shock (Voc-T). These responses were attenuated but not abolished by combined bilateral transection of the 'genito-spinal' nerves (i.e. pelvic, hypogastric and pudendal). Subsequent bilateral vagotomy further reduced or abolished the residual responses. In the present study, spinal cord transection above the known level of entry of the genito-spinal nerves was combined with bilateral vagotomy. In ovariectomized rats, after spinal cord transection at thoracic 7 (T7X), lumbar 5 (L5X) levels, or sham surgery (Sh), responses to VS were measured, the vagus nerves were then transected bilaterally, and responses to VS were again measured. VS significantly increased Voc-T and PD after sham procedure or spinal cord transection at either level. Subsequent bilateral vagotomy abolished the VS-induced increase in PD in the T7X group. Due to low survival rate, the effect of vagotomy on Voc-T could not be determined. Consequently, we performed a second experiment. In non-ovariectomized rats, VS significantly increased PD but reduced Voc-T in the T7X group compared to the Sh group, and subsequent bilateral vagotomy abolished both responses. These findings provide evidence that, in the rat, the vagus nerves provide a functional sensory pathway from the reproductive tract directly to the medulla oblongata of the brain, bypassing the spinal cord.

Complete immunization against Trypanosoma cruzi verified in individual mice by complement-mediated lysis

Experimental systems to assay immunity against Trypanosoma cruzi usually demonstrate partial resistance without excluding the establishment of sub-patent infections in protected animals. To test whether Swiss mice immunized with attenuated parasites might develop complete resistance against virulent T. cruzi, experiments were performed involving challenge with low numbers of parasites, enhancement of local inflammation and the combination of natural and acquired resistance. Absence of infection was established after repeated negative parasitological tests (including xenodiagnosis and hemoculture), and lack of lytic antibody was tested by complement mediated lysis. Immunization with 10(7) attenuated epimastigotes conferred protection against the development of high levels of parasitemia after challenge with Tulahuen strain, but was unable to reduce the number of infected animals. However, when a strong, delayed-type hypersensitivity reaction was triggered at the site of infection by injecting a mixture of virulent and attenuated T. cruzi, a significant proportion of immunized animals remained totally free of virulent infection. The same result was obtained when the immunization experiment was performed in four month old Swiss mice, displaying a relatively high natural resistance and challenged with wild, vector-borne parasites. These experiments demonstrate that complete resistance against T. cruzi can be obtained in a significant proportion of animals, under conditions which replicate natural, vector delivered infection by the parasite.

Inhibition of withdrawal responses by pelvic nerve electrical stimulation

In urethane-anesthetized rats, the compound action potential of the pelvic nerve was found to consist of three different waves, two in the A delta fiber and one in the C-fiber range of conduction velocity. Electrical stimulation of the pelvic nerve produced a complete inhibition of the withdrawal response to noxious foot pinch or foot compression. The electromyographic (EMG) activity of the contralateral posterior biceps muscle was used to record the withdrawal response. The withdrawal response inhibition was related to the duration and the frequency of electrical stimulation. Low (5-10 Hz) and high (100-300 Hz) frequencies were ineffective in inhibiting the withdrawal response, whereas intermediate frequencies (20-80 Hz) produced a complete inhibition of the withdrawal response. Short (300 ms) trains of stimulation inhibited the withdrawal response only during the stimulation period. Longer trains of stimulation (500 ms-10 s) produced long-lasting inhibition of the response to noxious stimulation. The inhibition persisted for up to 20 s after the end of electrical stimulation of the pelvic nerve. A delta fiber stimulation was adequate to inhibit the withdrawal response in most (15 out of 17) of the animals. However, A delta plus C-fiber stimulation was needed to inhibit the response to noxious stimulation in two animals. In addition to inhibiting the response to noxious stimulation, pelvic nerve electrical stimulation reflexively activated abdominal muscles. On the basis of present findings using electrical stimulation, it can be suggested that, in the rat, A delta and C-visceral afferents of the pelvic nerve mediate the analgesic effect of vaginocervical probing pelvic and A delta afferents the contraction of abdominal muscles in the fetus-expulsion reflex.

Pharmacokinetics of the novel anticonvulsant HEPP after single intravenous administration of three different doses in dogs

HEPP (D, L-3-hydroxy-3-ethyl-3-phenylpropanamide) is a novel compound with a wide spectrum of anticonvulsant activity and relatively low toxicity. The aim of this investigation was to study the pharmacokinetics of HEPP in mongrel dogs and to assess its linearity after intravenous administration of 8, 15, and 30 mg kg-1. A biphasic disappearance pattern with a rapid distribution phase was observed in the plasma concentration versus time curve. The mean terminal half-life (t1/2 beta) was the same after the three doses (3.4 +/- 0.15 h) and the mean half-lives of the distribution phase (t1/2 alpha) were not significantly different after the three doses (0.09 +/- 0.02, 0.08 +/- 0.07, and 0.11 +/- 0.03 h for 8, 15, and 30 mg kg-1 respectively). The mean AUC0-infinity values were 44.1 +/- 10.8, 72.1 +/- 8.8, and 127.4 +/- 23.2 micrograms h mL-1, respectively, showing a linear increase. The individual values of AUC0-infinity corrected for the administered dose (AUC0-infinity/D) were 0.29 +/- 0.04, 0.23 +/- 0.05, and 0.22 +/- 0.06 h mL-1. These values were not statistically different. Neither the mean residence time (MRT = 4.55 +/- 1.50, 4.90 +/- 1.32, and 5.07 +/- 1.95 h), the steady state volume of distribution (Vss = 0.86 +/- 0.11, 1.01 +/- 0.17, and 1.20 +/- 0.40 L kg-1) nor the systemic clearance (Cl = 3.36 +/- 0.82, 3.53 +/- 0.44, and 4.02 +/- 0.68 mL min-1 kg-1) showed significant differences between doses. The values of Vss suggest that HEPP is distributed in the whole body fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Disposition kinetics of HEPP in rats after intravenous, oral, and intraperitoneal administration. Correlation of plasma and brain levels with the anticonvulsant effect

D, L-3-hydroxy-3-ethyl-3-phenylpropanamide (HEPP) is a synthetic drug with anticonvulsant effects in a variety of seizure models. HEPP pharmacokinetics was studied after single 50 mg kg-1 intravenous (i.v.), intraperitoneal (i.p.), and oral (PO) administration in male albino Wistar rats. The plasma concentration against time curves showed a biphasic decay pattern with a similar distribution phase and the same terminal rate constant (beta = 0.22 h-1) by all three routes. The apparent volume of distribution at steady state (Vss = 0.80 L kg-1) indicates that HEPP is extensively distributed in extracellular tissues. This finding agrees very well with its low binding to plasma protein (mean bound fraction = 19.3 +/- 1.1%). The systemic clearance (Cl) was very low (3.30 mL min-1 kg-1). The bioavailability after IP and PO administration was 0.80 and 0.60 respectively. In the pharmacokinetic-pharmacodynamic studies a direct relationship was found between the protective effect of HEPP against pentylenetetrazole (PTZ) induced seizures and its concentration in plasma and/or brain. The concentrations at half-maximal effect (EC50) with 95% confidence interval (Cl) were 70.6 (66-75.5) micrograms mL-1 in serum and 60.1 (55.4-65.1) micrograms g-1 in brain. There was a rapid uptake of HEPP into the brain, and after the distributive phase, the disappearances in plasma and brain were almost parallel [C(serum) = 109 e-0.25t, r2 = 0.95; C(brain) = 38 e-2.53t + 91 e-0.21t, r2 = 0.93], with a C(brain)/C(plasma) ratio of 1.1.