Lower-limb force production in individuals after unilateral total knee arthroplasty

OBJECTIVE: To determine and compare lower-limb force production during a single-leg horizontal press in involved and uninvolved limbs in people with unilateral total knee arthroplasty (TKA) and the limb of age- and gender-matched subjects. DESIGN: Quasi-experimental, posttest only control group design. SETTING: Subjects living in the community and were tested at a university facility. PARTICIPANTS: Nine people with unilateral TKA and 9 subjects without TKA volunteered. The mean postsurgery time for the TKA group was 15.89+/-6.62 months. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Force production in kilograms during a single-leg press. RESULTS: Lower-limb force production differed significantly between involved and uninvolved limbs (P=.007) for the unilateral TKA group. Lower-limb force production of the involved limb in persons with unilateral TKA was significantly lower than the limb of the age- and gender-matched controls (P=.0001). CONCLUSIONS: Lower-limb force production on the involved side was significantly lower than the uninvolved side. When compared with an age-matched control group, subjects with unilateral TKA produced less force during a single-leg horizontal press.     

Diode laser thermal keratoplasty to correct hyperopia

PURPOSE: We investigated long-term efficacy, predictability, stability, and safety of diode laser thermal keratoplasty (DTK) to correct hyperopia. METHODS: DTK was performed on 24 eyes (18 patients). Eight eyes with high hyperopia (mean +4.75 +/- 0.63 D; range +3.50 to +5.50 D) received 12 pairs of coagulation spots at 6-mm and 7-mm treatment zone diameters; eight eyes with low hyperopia (mean +2.25 +/- 0.40 D; range +1.50 to +2.75 D) received eight coagulation spots at 8 mm, and eight eyes with low hyperopia (mean +1.50 +/- 0.46 D; range +1.25 to +2.25 D) were treated to induce mild myopia (-1.50 D) in the non-dominant eye for monovision using eight pairs of spots at 7 and 8-mm diameters. Minimum follow-up was 18 months. RESULTS: Mean decrease in cycloplegic refraction at 18 months was 5.00 +/- 0.38 D in the high hyperopia group, 1.75 +/- 0.19 D in the low hyperopia group, and 3.25 +/- 0.27 D in the presbyopia group. Mean increase in uncorrected visual acuity (UCVA) at 18 months was 8.125 +/- 2.1 Snellen lines in the high hyperopia group, 6.625 +/- 0.744 lines for low hyperopia; decrease of 1.00 +/- 1.85 line occurred in the presbyopia group. Near UCVA in the presbyopia group improved by 3.875 +/- 0.83 Jaeger lines. Best spectacle-corrected visual acuity (BSCVA) was restored by 3 months in all eyes. CONCLUSION: DTK was an effective and fairly safe procedure, with reasonable predictability and stability. Nomograms for laser energy level, treatment zone diameter, and number of spots need improvement.     

Comparison of effects on left ventricular filling pressure of intravenous nesiritide and high-dose nitroglycerin in patients with decompensated heart failure

The results of this study showed an advantage of nesiritide compared with high-dose nitroglycerin in the treatment of patients with decompensated heart failure. Nesiritide resulted in an early decrease in pulmonary capillary wedge pressure (< or =15 minutes), which was sustained throughout the study period (24 hours) without the need for up-titration. In contrast, the onset of the nitroglycerin-mediated hemodynamic effect was delayed, and despite aggressive up-titration, the decrease in pulmonary capillary wedge pressure was gradually attenuated because of the early development of tolerance.     

Latent inhibition and overswitching in schizophrenia

Attention disorders in schizophrenia are manifested in two different ways. On the one hand, the schizophrenia patient tends to keep a learned response even after it ceases to be relevant (perseveration). On the other hand, the schizophrenia patient tends to replace an adaptive response without being given a reason to do so (overswitching). In the present study, overswitching was investigated in relation to latent inhibition (LI), which is the normal ability to ignore nonrelevant stimuli. A new tool--the Combined Attention Test--was used for this purpose in a group of 41 unmedicated schizophrenia patients, divided into subgroups of patients with predominantly positive and negative symptoms, and 24 normal controls. The results show that positive schizophrenia patients, who exhibited high levels of overswitching, also revealed impaired LI, while the negative schizophrenia group, as well as normal controls, exhibited intact LI. These findings suggest that overswitching is a specific attention deficit in positive schizophrenia. We discuss the possibility that impaired LI is a consequence of overswitching and comment on the putative neurophysiology.     

Congenital hydrocephalus and continuous spike wave in slow-wave sleep--a common association?

Early-onset hydrocephalus was identified as the common denominator in 5 of 12 consecutive patients with Landau-Kleffner syndrome or continuous spike wave in slow-wave sleep who presented during the last 6 years. This association seems to be more common than expected, and the course of epileptic disease and outcome differs from that of previous reports. We present the clinical cases and discuss the possible connection between early hydrocephalus and epilepsy, especially continuous spike wave in slow-wave sleep. A retrospective analysis was undertaken of the clinical course and electroencephalographic (EEG) data before and after the development of continuous spike wave in slow-wave sleep in a group of five children with early-onset hydrocephalus identified in three epilepsy clinics in Israel. Landau-Kleffner syndrome or continuous spike wave in slow-wave sleep was identified in 12 patients during 6 years (1995-2000). Five patients had a history of early-onset hydrocephalus. Three patients had ventriculoperitoneal shunts; two of them were never shunted. Patients' seizures and continuous spike wave in slow-wave sleep epileptiform activity was resistant to appropriate anticonvulsant treatment. Pediatric neurologists and neurosurgeons should be aware of the association between continuous spike wave in slow-wave sleep and early-onset hydrocephalus. When a child with hydrocephalus presents with behavioral, cognitive, or motor deterioration, he or she should undergo sleep EEG in addition to investigation of shunt function. Our series demonstrated the presence of continuous spike wave in slow-wave sleep and localization-related epilepsy that did not originate from the shunt site. This group of patients is heterogeneous, and the exact trigger for continuous spike wave in slow-wave sleep development is still unclear.     

Bone strength in multiple sclerosis: cortical midtibial speed-of-sound assessment

It has been previously suggested that multiple sclerosis (MS) patients are at increased risk for osteoporosis due to reduced mobility, decreased exposure to sunlight and recurrent steroid treatment. In order to systematically evaluate bone strength we assessed 256 MS patients (171 females, 75 males) through quantitative ultrasound measurement of cortical bone. Tibial speed of sound (SOS, m/sec) was measured at midpoint of the tibial shaft using a Soundscan 2000 (Myriad Ultrasound Systems, Rehovot, Israel) and results were compared to age- and gender-matched population norms. T-score distribution in male MS patients was similar to normal population. In contrast, for female MS patients T-score distribution was significantly different from population norms, reflected by increased SOS in 30.4% (T-score intervals 1-2 and >2 above normal values; P=0.001), compared with 7.4% in controls. These findings held true for both female patients younger and older than 45 years of age. Increased neurological disability and specifically motor involvement were more frequent in female patients with increased SOS (P<0.05). Bone strength was preserved in MS patients. In a subgroup of female patients increased SOS was conceivably related to spasticity.     

Protective effect of topical iodine containing anti-inflammatory drugs against sulfur mustard-induced skin lesions

Previous studies have shown the antidotal efficacy of topical iodine at 15 and 30 min post-exposure to sulfur mustard (SM). Here we demonstrate efficacy at longer intervals (20, 30, 45, and 60 min, respectively, for data) using an improved topical povidone-iodine preparation termed N66, which contains steroidal and non-steroidal anti-inflammatory agents. In the mouse, N66 reduced severity of ear edema by 43, 47, 44, and 36%; ear epidermal ulceration by 74, 58, 45, and 58%; and epidermal necrosis by 54, 34, 26, and 31% at the respective time points. A similar effect was observed with encrustation. The healing marker, grade of acanthotic area, showed dramatic increases of 39.6-, 25.3-, 20.9-, and 22-fold. Severity of the dermal parameters, acute inflammation and dermal necrosis, was reduced by 63, 34, 34, and 38% and 80, 54, 54, and 59%, respectively. In guinea pig skin, topical treatment with N66 45 min post-exposure reduced the SM-induced ulceration area by 75%. The histological parameters subepidermal microblister formation, epidermal ulceration, epidermal necrosis, and encrustation were reduced by 63, 61, 41, and 41%, respectively. The healing marker, grade of acanthotic area, was elevated by 73%. N66 induced a statistically significant reduction in two dermal markers for tissue damage: acute inflammation (33%) and dermal necrosis (48%). Reduced skin damage was also observed in areas adjacent the treated sites. The pharmacologically active components of N66 showed additive effect. These findings suggest that the povidone-iodine preparation combined with anti-inflammatory agents functions as a potent antidote against skin lesions induced by SM at relatively long intervals between exposure and treatment.Part of this work was presented at the 41st Annual Meeting of the American Society of Toxicology, Nashville, TN, March 17–21, 2002.     

Local and non-local deficits in amblyopia: acuity and spatial interactions

Amblyopic vision is thought to be limited by abnormal long-range spatial interactions, but their exact mode of action and relationship to the main amblyopic deficit in visual acuity is largely unknown. We studied this relationship in a group (N=59) of anisometropic (N=21) and strabismic (or combined, N=38) subjects, using (1) a single and multi-pattern (crowded) computerized static Tumbling-E test with scaled spacing of two pattern widths (TeVA), in addition to an optotype (ETDRS chart) acuity test (VA) and (2) contrast detection of Gabor patches with lateral flankers (lateral masking) along the horizontal and vertical axes as well as in collinear and parallel configurations. By correlating the different measures of visual acuity and contrast suppression, we found that (1) the VA of the strabismic subjects could be decomposed into two uncorrelated components measured in TeVA: acuity for isolated patterns and acuity reduction due to flanking patterns. The latter comprised over 60% of the VA magnitude, on the average and accounted for over 50% of its variance. In contrast, a slight reduction in acuity was found in the anisometropic subjects, and the acuity for a single pattern could account for 70% of the VA variance. (2) The lateral suppression (contrast threshold elevation) in a parallel configuration along the horizontal axis was correlated with the VA (R2=0.7), as well as with the crowding effect (TeVA elevation, R2=0.5) for the strabismic group. Some correlation with the VA was also found for the collinear configuration in the anisometropic group, but less suppression and no correlation were found for all the vertical configurations in all the groups. The results indicate the existence of a specific non-local component of the strabismic deficit, in addition to the local acuity deficit in all amblyopia types. This deficit might reflect long-range lateral inhibition, or alternatively, an inaccurate and scattered top-down attentional selection mechanism.