Diagnosis and management of McFarland fractures

BACKGROUND

McFarland fracture is the eponym for a rare Salter Harris III or IV fracture involving the medial distal tibia. These fractures can be difficult to diagnose without a high index suspicion and appropriate radiographic imaging. These fractures may result in significant growth disturbances to the pediatric patient. When diagnosed and treated acutely, these fractures can be managed with cast immobilization and close follow up. If diagnoses in a delayed fashion they can result in significant morbidity including prolonged casting and possible surgical treatment.

CASE REPORT

In this case report we discuss a pediatric patient with a delayed presentation McFarland fracture which was initially diagnosed and treated as an ankle sprain. He required a prolonged course of treatment and we describe his clinical progression. We review the literature regarding this fracture pattern including history, acute management and outcomes. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: McFarland fractures are rare Salter Harris III fractures of the medial malleolus. These ankle fractures affect patients nearing skeletal maturity and may be difficult to diagnose without the appropriate orthogonal X-ray imaging. Also, a missed diagnosis can lead to unnecessary morbidity to the patient. If diagnosed acutely, these fractures can be easily treated with immobilization but if allowed to become chronic they require prolonged periods of casting and possibly even surgical intervention. A patient with a specific constellation of symptoms and history should raise suspicion for these injuries and prompt a thorough workup.

The Impact of Age and Cognitive Reserve on Resting-State Brain Connectivity

Cognitive reserve (CR) is a protective mechanism that supports sustained cognitive function following damage to the physical brain associated with age, injury, or disease. The goal of the research was to identify relationships between age, CR, and brain connectivity. A sample of 90 cognitively normal adults, ages 45–64 years, had their resting-state brain activity recorded with electroencephalography (EEG) and completed a series of memory and executive function assessments. CR was estimated using years of education and verbal IQ scores. Participants were divided into younger and older age groups and low- and high-CR groups. We observed greater left- than right-hemisphere coherence in younger participants, and greater right- than left-hemisphere coherence in older participants. In addition, greater coherence was observed under eyes-closed than eyes-open recording conditions for both low-CR and high-CR participants, with a more substantial difference between recording conditions in individuals high in CR regardless of age. Finally, younger participants low in CR exhibited greater mean coherence than younger participants high in CR, whereas the opposite pattern was observed in older participants, with greater coherence in older participants high in CR. Together, these findings suggest the possibility of a shift in the relationship between CR and brain connectivity during aging.

Determination of bull sperm membrane permeability to water and cryoprotectants using a concentration-dependent self-quenching fluorophore

The objective of this study was to determine the membrane permeability characteristics of bovine spermatozoa. These included the hydraulic conductivity (Lp), the permeability coefficients (Ps) of four common cryoprotective agents (CPAs) and the associated reflection coefficients (sigma). Stopped-flow fluorometry was applied in order to capture rapid cell volume changes under anisosmotic conditions in the absence or presence of permeant solutes (CPAs). This technique utilizes a concentration-dependent self-quenching entrapped fluorophore. The resulting cell volume changes were used in three-parameter fitting calculations to compute Lp in the absence of permeant solutes and Ps and Lp in the presence of permeating solutes (CPAs) at 22 degrees C. The hydraulic conductivity in the absence of permeating solutes was estimated to be 0.68+/-0.05 microm/min/atm (mean+/-SEM). Hydraulic conductivity (Lp) in the presence of CPAs was 0.91+/-0.27 (mean+/-SEM), 0.29+/-0.04, 0.42+/-0.05, and 0.39+/-0.03 microm/min/atm in the presence of dimethylsulfoxide (Me(2)SO), glycerol, propylene glycol (PG), and ethylene glycol (EG), respectively. The values for Ps were estimated to be 1.72+/-0.36, 1.75+/-0.03, 2.47+/-0.24, and 1.49+/-0.33 x 10(-3)cm/min for Me(2)SO, glycerol, PG, and EG, respectively. The data were used to simulate volume excursions during addition and removal of CPA, to predict the different effects of the four CPAs.

How covert are covertly manipulated diets?

OBJECTIVE

To quantitatively assess subjects' ability to detect hedonic (palatability), sensory and nutritional differences between covertly manipulated high-fat (HF) and low-fat (LF) diets. SUBJECTS AND DIETS: This study examined the response of 16 subjects (eight men, eight women) to 20 LF and 20 HF versions of manipulated foods. Average percentage protein:fat:carbohydrate (by energy) and energy density (ED) of the two diets were 13:25:62, 371 kJ/100 g and 13:50:37, 672 kJ/100 g, respectively.

PROTOCOL

Subjects were asked to simultaneously assess the HF and LF versions of each food in terms of (i) subjective pleasantness of each food, (ii) perceived differences in appearance, smell, taste and texture of the foods, and (iii) for each sample to assess whether it was high or low in energy, protein, carbohydrate, fat, fibre, sugar and salt.

ANALYSIS

Perceived pleasantness of HF and LF versions of the foods was compared by analysis of variance. Comparisons used chi-squared tests of independence to assess departure from the null hypothesis of no perceived difference in remaining parameters (ii-iii).

RESULTS

On average, subjects exhibited no significant preference for LF or HF versions of the foods (no difference 15 foods, three HF foods more pleasant, two LF foods more pleasant (P<0.03)). On average there were no general differences in comparison of sensory attributes that were consistently ascribable to the LF or HF foods, although there were numerous significant differences for individual foods. Subjects appeared unable to distinguish the HF foods as being HF (66% of estimates) and guessed correctly 33% of the time. They were better able to categorize the LF foods correctly (53% correct). On aggregate 43% of HF and LF foods were correctly identified. Subjects appeared able to detect sensory differences between foods but not to relate them to energy or nutrient content of these foods.

CONCLUSIONS

These data suggest that subjects are on average not able to perceive large differences in the fat content of diets manipulated in this manner. In general the assumption that the manipulation of such foods is covert appears to hold, but subjects were far better at correctly identifying certain food types (dairy-based) over others.

Isolated symptomatic peripheral neuropathy in type 1 insulin-dependent diabetes mellitus

Diabetic neuropathy is probably the most frequent of the chronic complications of diabetes, and is usually found in association with diabetic retinopathy and/or nephropathy. We report seven patients with long-standing insulin-dependent diabetes mellitus in whom symptomatic peripheral neuropathy was the first and only documented complication. The diagnosis of peripheral symmetrical neuropathy was based on the presence of symptoms and abnormal physical findings, confirmed with abnormal electrophysiological and/or vibratory and thermal threshold measurements. Diabetic retinopathy and nephropathy were absent. We conclude that in some type 1 insulin-dependent diabetic patients, similar to what has been reported in type 2 non-insulin-dependent diabetes, peripheral neuropathy may be the first chronic complication to become manifest. This observation provides additional evidence to suggest that each of the diabetic complications may have a different pathogenic mechanism.

The dual effects of ouabain on 45Ca2+ transport and contractility in adult rat ventricular myocytes

We used isolated ventricular myocytes to study 45Ca2+ transport in the presence of three concentrations of ouabain (10 nM, 1 microM, and 100 microM) in Tyrode solution containing 1 mM CaCl2. The cells were quiescent and during 45Ca2+ uptake and 45Ca2+ efflux experiments, 10 nM ouabain decreased Ca2+ content, 1 microM, didn't change it appreciably, and 100 microM increased it significantly. Qualitatively, the same results were obtained at 22 degrees C and 35 degrees C. Ouabain did not significantly affect the electrical activity of isolated, electrically stimulated myocytes, but it increased the amplitude of shortenings of these myocytes in a dose-dependent manner. Thus, the positive inotropic effect of ouabain at therapeutic doses (less than or equal to 10 nM) occurs in spite of decreased Ca2+ content, while at high toxic doses the positive inotropic effect is accompanied by an increment in Ca2+ content. These data support the hypothesis that the mechanisms of positive inotropy of ouabain are different at therapeutic and toxic concentrations of this drug. Finally, our study demonstrates that the effects of low doses of ouabain are independent of the release of endogenous catecholamines.

A computerized system for measuring detection sensitivity over the visual field

A device is described for comprehensively measuring the capability of human operators to detect and react to visual signals occurring at a variety of locations throughout the functional visual field. The system is completely automated and computerized, and provides both documentation files and descriptive graphics of the operator's performance immediately upon completion of testing. Sensitivity of detection can be measured for red, yellow, and green stimulus colors in a testing configuration which mimics commonplace surveillance of the ordinary viewing field. An abbreviated listing of the main operating program software is provided.

The Comprehensive Blood Bank Survey Program of the College of American Pathologists--1977

The 1977 CAP Comprehensive Blood Bank Survey was sent to 2487 laboratories in the United States and five foreign countries. The results show that ABO and Rh testing has a continued concurrence of greater than 94.8% between participating and referee laboratories, while antibody detection was 95.9% effective on the type problem normally encountered in a transfusion service. Cross match showed a concurrence rate of 97.3% or better. Although these testings are artificial and cannot be directly extrapolated into effectiveness of patient care, they can be compared with each other and show a standard of excellency in the laboratory which is a good or better than that found in previous studies. A series of ungraded specimens and questionnaires shows that most laboratories used a 51 degree C heat elution method for antibody elution, but slightly better results were obtained with the Rubin technic. A second study showed that the grading of a positive direct antiglobulin test was fairly reproducible throughout the country.