MRI findings in Hirayama’s disease: flexion-induced cervical myelopathy or intrinsic motor neuron disease?

Hirayama’s disease is a benign juvenile form of focal amyotrophy affecting the upper limbs. Previous studies have suggested that the disorder is a neck flexion induced cervical myelopathy. We report clinical and magnetic resonance imaging findings in nine patients with Hirayama’s disease. Cervical imaging of seven patients revealed spinal cord changes consisting of focal atrophy and foci of signal alterations. On neck flexion a forward movement and mild reduction in the anteroposterior diameter of the lower cervical cord against the vertebral bodies was noted in affected individuals as well as in five normal controls. In contrast to earlier reports, none of our patients showed complete obliteration of the posterior subarachnoid space. Measurement of the anteroposterior spinal cord diameter in each vertebral segment (C4–C7) revealed no significant differences in the degree of spinal cord flattening between the two groups. Furthermore, two of our patients had significant degenerative changes in the cervical spine (disc herniation, retrospondylosis) contralateral to the clinically affected side. These degenerative changes resulted in a marked cord compression on neck flexion but were not associated with ipsilateral clinical abnormalities or spinal cord alterations. Our results argue against a flexion-induced cervical myelopathy and support the view that Hirayama’s disease is an intrinsic motor neuron disease. Received: 15 March 1999 Received in revised form: 25 May 1999 Accepted: 1 June 1999     

Association of dialyzer reuse and hospitalization rates among hemodialysis patients in the US

OBJECTIVES: To determine if reuse of hemodialyzers is associated with higher rates of hospitalization and their resulting costs among end-stage renal disease (ESRD) patients. METHODS: Noncurrent cohort study of hospitalization rates among 27,264 ESRD patients beginning hemodialysis in the United States in 1986 and 1987. RESULTS: Dialysis in free-standing facilities reprocessing dialyzers was associated with a greater rate of hospitalization than in facilities not reprocessing (relative rate (RR) = 1.08, 95% confidence interval (CI), 1.02-1.14). This higher rate of hospitalization was observed with dialyzer reuse using peracetic/acetic acids (RR = 1.11, CI 1. 04-1.18) and formaldehyde (RR = 1.07, CI 1.00-1.14), but not glutaraldehyde (p = 0.97). There was no difference among hospitalization rates in hospital-based facilities reprocessing dialyzers with any sterilant and those not reprocessing. Hospitalization for causes other than vascular access morbidity in free-standing facilities reusing dialyzers with formaldehyde was not different from hospitalization in facilities not reusing. However, reuse with peracetic/acetic acids was associated with higher rates of hospitalization than formaldehyde (RR = 1.08, CI 1.03-1.15). CONCLUSIONS: Dialysis in free-standing facilities reprocessing dialyzers with peracetic/acetic acids or formaldehyde was associated with greater hospitalization than dialysis without dialyzer reprocessing. This greater hospitalization accounts for a large increment in inpatient stays in the USA. These findings raise important concerns about potentially avoidable morbidity among hemodialysis patients. Copyright Copyright 1999 S. Karger AG, Basel     

Body fat, caloric intake, and plasma leptin levels in women with anorexia nervosa.

OBJECTIVE: To measure serum leptin concentrations in women with anorexia nervosa (AN) and to identify independent predictors of leptin levels, thereby allowing hormone levels to be modeled using regression analysis. METHODS: A cross-sectional study of 15 AN inpatients and 16 healthy control subjects. Age, height, weight, percent body fat, total caloric intake, fat intake, and fasting plasma leptin levels were recorded. Stepwise forward regression analysis was carried out to identify predictors of leptin levels. RESULTS: Circulating leptin concentrations in AN were 3.5+/-0.5 versus 7.6+/-1.2 ng/ml in control subjects. Percent body fat correlated best with leptin levels in anorexic and control subjects (r =.63; p =.0002), with caloric intake showing only a moderate correlation (r = .47; p = .008). Only percent body fat was a significant predictor of plasma leptin levels in our regression model. DISCUSSION: Leptin levels are proportionately lower in AN as compared to healthy controls. It appears that physiological regulation of plasma levels with respect to percent body fat is maintained in individuals with little body fat.     

Individual versus job-based health insurance: weighing the pros and cons

Although the majority of insured Americans receive their health insurance through their employers, some depend on the individual health insurance market. However, with increased criticism of the lack of choice in group coverage and various proposals including subsidies or tax credits to decrease the number of uninsured, the individual market may start to play a larger role. In this paper we conclude that although efficient large-group insurance will appropriately continue to exist, the individual market appears to be improving, in both administrative cost and protection against high premiums associated with high risk. For diverse workers now in small groups with little plan choice, the individual market might become a reasonable alternative.     

Red wine inhibits the cell-mediated oxidation of LDL and HDL

OBJECTIVE: We compared the in vitro effects of red wine, white wine and ethanol on the cell mediated oxidation of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) by three frequently-used assays. METHODS: LDL and HDL isolated from normolipidemic human serum were incubated with J774.A1 macrophages in DMEM with copper, with or without red wine, white wine or ethanol (equivalent to 0.2 mg ethanol/ml). Lipoprotein oxidation was assessed by conjugated diene formation as measured by changes in absorbance at 234 nm (deltaA234), thiobarbituric-acid-reactive-substance (TBARS) production and trinitrobenzene-sulfonic-acid (TNBS) reactivity. RESULTS: Red wine (0.2 mg ethanol/mL) inhibited LDL oxidation as indicated by an 85.7% decrease in absorbance at 234 nm, a 96.5% decrease in TBARS production and complete prevention of the decrease in TNBS reactivity. White wine and ethanol did not have any significant effect at 0.2 mg/mL. White wine at 1.0 mg ethanol/mL inhibited TBARS production from LDL by 84.1%. Red wine (0.2 mg ethanol/mL) inhibited HDL oxidation as indicated by a 78.9% decrease in deltaA234, an 81.7% decrease in TBARS production and by no change in TNBS reactivity. White wine and ethanol had no effect at 0.2 mg/mL. White wine at 1.0 mg ethanol/mL inhibited TBARS production from HDL by 66.4%. CONCLUSIONS: These results indicate that red wine inhibits the cell mediated oxidation of lipoproteins, that white wine is not as effective as red wine and that the effect of the red wine is not due to its ethanol content.     

Effects of continuous oral nicotine administration on brain nicotinic receptors and responsiveness to nicotine in C57Bl/6 mice

 The route of drug delivery is an important consideration in studies that evaluate the long-term biobehavioral adaptations that occur in response to chronic drug administration. Continuous infusions (intravenous or subcutaneous) or intermittent intraperitoneal (or subcutaneous) injections are the most commonly utilized routes of chronic drug delivery in these studies. The purpose of the present study was to determine the effects of chronic oral nicotine exposure on sensitivity to nicotine and brain nicotinic cholinergic receptors in female C57Bl/6 mice. Mice were randomized to different treatment groups that received 2% saccharin, containing 0–200 μg/ml nicotine (free base). In preliminary experiments, radiotelemetry devices were implanted in the mice; consumption of the nicotine-containing drinking solution caused a significant increase in home-cage nocturnal (but not diurnal) activity and also altered circadian alterations in body temperature. Oral nicotine exposure resulted in dose-related elevations in plasma levels of cotinine, a primary nicotine metabolite. Continuous exposure (30 days) to oral nicotine (200 μg/ml) resulted in the expression of significant tolerance to the locomotor depressant and hypothermic actions of acute nicotine challenge. This tolerance was accompanied by a significant increase in brain nicotinic receptor number assessed by quantitative autoradiography using [³H]-cytisine (α4 nAChr) and [¹²⁵I]-α-bungarotoxin (α7 nAChr) as radioligands. These results suggest that chronic oral nicotine delivery to female C57Bl/6 mice results in behavioral and biochemical changes that resemble changes that occur following other routes of chronic nicotine delivery. Received: 30 January 1998 / Final version: 25 June 1998     

Continent Cutaneous Urinary Diversion Using The Full-Thickness Bowel Flap Tube as Continence Mechanism: A Simplified Tunneling Technique

Purpose

We present a time and labor saving embedding technique for a full-thickness bowel flap tube used as a continent outlet.

Materials and Methods

In 17 patients the bowel flap tube was extramurally embedded instead of being submucosally tunneled. The reservoir was attached to the abdominal wall to reinforce the continence mechanism and prevent the tunnel from opening.

Results

All 17 patients are completely continent and 14 of 16 evacuate urine easily with a 14F catheter. Due to recurrent stomal stenosis 1 patient with severe diabetes has undergone incontinent diversion.

Conclusions

Our described tunneling procedure for the full-thickness bowel flap tube is easy to perform and provides excellent continence.     

Influence of selective phosphodiesterase inhibitors on human neutrophil functions and levels of cAMP and Cai

Summary Chromatographic analysis of 3,5-cyclic nucleotide phosphodiesterase (PDE) isoenzymes in the cytosol of human neutrophils shows the predominant presence of PDE IV (cAMP specific) and PDE V (cGMP specific). PDE IV is characterized by (1) cAMP selectivity, (2) a K_M for cAMP of 1.2 M and (3) a typical rank order of IC ₅₀-values for PDE inhibitors: 0.13, 0.17, 47 and 9.5 M for PDE IV selective rolipram, PDE III/IV selective zardaverine, PDE III selective motapizone and unselective 3-isobutyl-l-methylxanthine (IBMX), respectively. Functions of polymorphonuclear leukocytes (PMN) such as N-formylmethionyl-leucyl-phenylalanine (fMLP)-stimulated superoxide release and fMLP/thimerosal elicited leukotriene (LT) biosynthesis are inhibited by these PDE inhibitors with the same rank order and even lower IC₅₀-values. Measurements of changes in cytosolic Ca_i in Fura-2 loaded PMN demonstrate a transient Ca_i increase after stimulation with 0.1 M fMLP and an additional sustained elevation of Ca_i levels in the presence of thimerosal. PDE inhibitors suppress this sustained phase of Ca_i release with the same rank order of IC₅₀-values as LT biosynthesis. The correlation between fMLP/thimerosal-induced LT biosynthesis and Ca_i levels reveal a Ca_i threshold of 150 nM for arachidonic acid metabolism. cAMP levels in PMN were elevated by PDE inhibitors alone by less than 2-fold. In the presence of fMLP however, cAMP was increased up to 10-fold and the efficacy of PDE inhibitors to increase cAMP paralleled their potency to inhibit PDE IV. It is concluded that (1) suppression of PMN functions is achieved by PDE IV inhibition, (2) necessary cAMP elevations are within 50% increase, (3) superoxide release was affected by cAMP/protein kinase A (PKA) directly whereas (4) for inhibition of LT biosynthesis a cAMP related reduction of Ca-influx is involved. Send offprint requests to Ch. Schudt at the above address