The effect of six degree of freedom loading sequence on the in-vitro compressive properties of human lumbar spine segments.

The complex, direction-dependent, poro-viscoelastic properties of the intervertebral disc (disc) suggest that investigations of the six degree of freedom (6DOF) behaviour may be susceptible to inter-test variation in mechanical response if the disc does not return to initial conditions between loading directions. No studies have quantified the effects of sequential multi-directional loading on the consistency of the compressive response of the disc throughout a 6DOF testing protocol. Therefore, the objective of this study was to determine the effect of 6DOF loading on the compressive properties (stiffness and phase angle) of human discs, as evaluated by a reference compression test performed after each single DOF test. Fourteen intact human functional spinal units (FSU) were tested in each of ±6DOFs (shear directions followed by bending and compression) across four orders of magnitude loading frequencies (0.001-1Hz), followed by reference compression tests while subjected to physiological preload, hydration, and body temperature conditions in a hexapod robot. Repeated measures ANOVA revealed significant within-subjects effects between the reference compression tests for modulus (p<0.001), stiffness (p<0.001), and phase angle (p=0.008). Significant post-hoc pairwise comparisons were initially seen between the control and other reference compression tests for stiffness and modulus after the shear DOFs, however, no significant differences were present after the final reference compression test compared to control. More pronounced effects were seen for stiffness in comparison to modulus and phase angle. These effects may be due to three potentials factors, which include the sequence of testing, the cohort of degenerative specimens, and/or cumulative creep due to the constant application of a follower load. While the sequence of test directions was chosen to minimise the biphasic effect, there may be other sequences, which could result in minimal changes in compressive properties.

Pain following stroke, initially and at 3 and 18 months after stroke, and its association with other disabilities.

BACKGROUND AND PURPOSE: A general hypothesis is that pain following stroke (PFS) causes disabilities. However, the clinical implication of PFS on other disabilities after stroke and vice versa has not been fully investigated. The aims of this observational study were to analyze the correlation between PFS and other disabilities at different time points after stroke, whether PFS can be a predictor of coming disabilities and whether other disabilities can be predictors of coming PFS. METHODS: Patients with a first-ever stroke were assessed initially (n = 109), and at 3 (n = 95) and 18 months (n = 66) after stroke for PFS, mobility, self-care as well as touch, proprioceptive, muscle tone, and movement functions. RESULTS: PFS was correlated to impaired upper extremity movement function on all occasions, while the correlations between PFS and other disabilities varied across the three occasions. Initial PFS and PFS at 3 months did not independently predict coming disabilities. Initial mobility limitation independently predicted PFS at 3 months and impaired touch function, initially and at 3 months, independently predicted PFS at 18 months. No other disabilities independently predicted coming PFS. CONCLUSIONS: The present results do not support the hypothesis that PFS causes other disabilities. Our results indicate that PFS is correlated to other disabilities; however, no ultimate conclusions can be drawn on causality. PFS was not a predictor of coming disabilities, while some disabilities were predictors of coming PFS.

Location and severity of spasticity in the first 1-2 weeks and at 3 and 18 months after stroke.

BACKGROUND AND PURPOSE: There is no consensus concerning the location or severity of spasticity, or how this changes with time after stroke. The purpose was to describe: the location and severity of spasticity, in different muscle groups, during the first 1-2 weeks and at 3 and 18 months after stroke; the association between the severity of spasticity and control of voluntary movements; and the occurrence of spasticity in younger versus older patients. METHODS: In a cohort of consecutive patients, the following parameters were assessed during the first 1-2 weeks (n = 109) and at 3 (n = 95) and 18 (n = 66) months after first-ever stroke: spasticity, by the Modified Ashworth Scale in different muscle groups; plantar-flexor clonus, by physical examination; and movement function, by the Lindmark Motor Assessment Scale. RESULTS: During the first 1-2 weeks and at 3 months after stroke, spasticity was most common in the anti-gravity muscles. The severity of upper extremity spasticity increased over time (P < 0.05). Upper extremity spasticity and movement scores were moderately associated (r = -0.61, P < 0.05). At 3 months, spasticity was more common amongst the younger patients (P < 0.05). CONCLUSIONS: The results confirm that spasticity is most common in the anti-gravity muscles and is associated with the control of voluntary movements. As the severity of spasticity also increased after 3 months, when neurally mediated spasticity is expected to have passed its peak, intrinsic muscle changes may play a larger role than neural components with the passage of time after stroke.

Disability test 10 days after acute stroke to predict early discharge home in patients 65 years and older.

OBJECTIVE: To identify prognostic instruments for the planning of care after acute stroke. DESIGN: Prospective study. SETTING: Stroke unit and geriatric rehabilitation unit. SUBJECTS: One hundred and fifteen consecutive acute stroke patients > or = 65 years old. MAIN OUTCOME MEASURES: Univariate and multivariate survival analyses. Length of hospital stay and residential form up to three months after onset. RESULTS: The average length of stay was significantly shorter if age <80 years, male, living with another person, normal sensory ability, Barthel Index (BI) score > or = 35 and Rivermead Mobility Index (RMI) score > or = 4, assessed 10 days after onset. Multivariate analysis, also including BI subtests, showed that RMI score > or = 4, which corresponds to the ability to rise from a chair in less than 15 seconds and remain erect for 15 seconds with or without aid, 10 days after onset, had the greatest impact on early discharge home after acute stroke, together with normal bladder function (BI subtest six), normal sensory ability and living with another person. CONCLUSION: The best predictor of early discharge home, 10 days after stroke onset, was the ability to rise from a chair with or without aid. This simple and quickly conducted test requires no special equipment and in the present study had a very high predictive value.

Postpartum concerns: a study of Tanzanian mothers.

Maternal and child health services in Tanzania have succeeded in implementing health care strategies to improve the health of children under 5 years of age. However, health care for childbearing women has not been a focus (Government of the United Republic of Tanzania/UNICEF, 1990). We examined what Tanzanian women perceive as concerns during the early postpartum period. A card sort was used with 50 primiparas and 50 multiparas from the Dar-es-Salaam urban area. Primiparas had significantly more worries and interests than did multiparas. Multiparas had significantly more confidence than primiparas had. Findings correspond to those of studies conducted on North American populations, suggesting that early postpartum concerns may be cross-cultural.

Thrombotic microangiopathy: a case report and review of the literature.

Thrombotic microangiopathy most likely represents a spectrum of diseases consisting of multiple etiologies that has a final common pathway of multiorgan microvascular thrombosis. The variable responses to several different modes of therapy would suggest that more than one pathogenetic mechanism is involved. Untreated, it has been associated with very high morbidity and mortality rates. A poor understanding of the basic disease process has prevented specific treatment modalities, although early diagnosis and availability of dialysis and blood product transfusion services remain crucial. Several modes of therapy have been used to date, with plasma exchange being the most effective method studied and shown to improve survival. On the basis of current knowledge, this form of treatment should be instituted promptly in severe cases. Anecdotal reports of recovery with vincristine or IgG alone or with the use of IgG after the apparent failure of plasma therapy appear promising and deserve further investigation as initial therapeutic measures used in thrombotic microangiopathy. Although the majority of patients recover with normal renal function, those with severe thrombotic microangiopathy may heal through sclerosis with residual hypertension and chronic renal impairment requiring continual medical therapy.

Modulation of sodium-cotransport systems by other ions.

After a brief review of Na+-cotransport systems which also accept other ions as co-ions or modifiers, modulation of the Na+-L-glutamate transport system in rabbit renal brush border membranes by K+ and H+ is discussed in more detail. Intravesicular K+ increases the initial uptake rate and electrogenicity of the cotransport. This effect of K+ is attributed to the formation of a K+-carrier complex that moves much more rapidly than do the other complexes. The resulting shift in rate limitancy (relative increase in overall rate over the relative increase in rate of step under consideration) from an electroneutral towards a charge-translocating pathway unmasks the electrogenicity of the initial L-glutamate uptake. A positive correlation between relative rate limitancy of the electrogenic pathway and electrogenicity is demonstrated supporting this model. Protons, in addition to acting as co-ions, modify Na+-glutamate cotransport by increasing both the initial rate and the electrogenicity of uptake. This phenomenon is assumed to represent a transition of the transport system from a carrier-like to an open channel-like translocation mode. Thus, the intrinsic properties of Na+-cotransport systems may vary under the influence of other ions. This holds true in particular for the electrogenicity of the initial transport rate which may change independently of alterations in charge stoichiometry.

Electrogenicity of sodium/L-glutamate cotransport in rabbit renal brush-border membranes: a reevaluation.

In order to clarify contradictory reports on the electrogenicity of sodium/L-glutamate cotransport, this cotransport was studied using brush-border membrane vesicles isolated from rabbit renal cortex. Beforehand, the claim that the symport of L-glutamate with Na+ is linked to simultaneous antiport with K+ has been confirmed by the demonstration that equilibrium exchange of L-glutamate is inhibited by potassium. Concerning the electrogenicity of the system, the following results are reported: net uptake of sodium-dependent L-glutamate uptake was stimulated when the transmembranal electrical potential difference was increased by replacing a sodium sulfate gradient by a sodium nitrate gradient. At 100 mM Na+ the 'relative electrogenicity' of the initial uptake in the presence of intravesicular potassium was 2-times higher than in its absence. At a sodium concentration of 20 mM, when overall uptake was reduced, the relative electrogenicity in the presence of K+ was even 3-fold higher than in K+-free media. The relative electrogenicity of sodium/D-glucose cotransport measured under the same experimental conditions was not affected by K+. These results are discussed in terms of a model where the apparent electrogenicity of a cotransport system is dependent on the extent to which the charge translocating step is rate limiting ('rate limitancy'). It is proposed that potassium antiport, while decreasing charge stoichiometry of Na+/glutamate transport, increases the relative rate limitancy of the transport step translocating three cations (probably two Na+, one H+) together with one glutamate. Thereby the positive electrogenicity of glutamate uptake increases, in complete contrast to what would be expected from simple considerations of charge stoichiometry.

Do health professionals agree on the parenting potential of pregnant women?

Although retrospective studies have suggested that the signs of potential parenting problems are present well before the child is born, successful prenatal screening is infrequent or absent in most clinical settings. For the most part, this lack of screening reflects the inherent difficulties in developing and using practical and reliable tools of assessment. Problems of reliability suggest that professionals from related disciplines often differ in their evaluations of clinical samples. This pilot study was designed to determine whether 12 professionals, four from each of three health disciplines concerned with child-abuse detection (nursing, medicine and social work), could agree on parenting risk status of 15 pregnant women. Assessment protocols were comprised of the most frequently cited predictive signs of poor parenting. Each rater evaluated the transcript of 15 prenatal interviews. The results indicate inconsistencies in rating both among and within the professional groups. These inconsistencies extended not only to the individual criteria from which the final scores were derived, but also to the total risk status. Even though specific instructions were given for the use of risk criteria, the raters often violated the instructions for coding in favor of their own idiosyncratic judgements.

Evaluation of physical therapy service for severely mentally impaired students with cerebral palsy.

The effects of two types of physical therapy service were studied over a five-month period in 19 severely mentally impaired cerebral palsied students aged 3 to 22 years. The students were paired and assigned to either a direct therapy treatment group or a supervised therapy management group. Ten similar students in a comparison group received no physical therapy. The study showed no significant difference in development of mature developmental reflexes, improvement of gross motor skills, or increase of passive joint motion among similar students placed in the direct, supervised, and comparison groups. This pilot study is not intended to decide the issue of physical therapy for these students. It does, however, indicate that objective tests may be used reliably to measure three major areas of sensory motor development. More extensive and longer-term studies are needed to determine the most beneficial form of physical therapy for this double-disability population.