Palmar arthroplasty for the treatment of the stiff swan-neck deformity

Palmar arthroplasty for the treatment of the stiff swan-neck deformity in rheumatoid arthritis is designed to correct the mechanical block to flexion that is caused by palmar plate adhesions (which obliterate the retrocondylar recess) and by collateral ligament contracture and adhesions. This procedure can be performed at the same time as correction of the primary cause of proximal interphalangeal joint (PIP) hyperextension (e.g., intrinsic tightness or flexor tenosynovitis) and can also be supplemented with superficialis tenodesis to minimize recurrent hyperextension. Postoperative flexor dynamic traction, which is started at 24 to 48 hours and continued for a minimum of 3 to 4 weeks, is critical to the maintenance of motion. Arthroplasty in 47 PIP joints in 14 hands of 9 patients demonstrate an increase in motion from +20 degrees hyperextension and 9.5 degrees flexion to -7 degrees extension and 72 degrees flexion postoperatively.     

Professor John Scott,folate and neural tube defects

John Scott (1940–2013) was born in Dublin where he was to spend the rest of his career, both as an undergraduate and subsequently Professor of Biochemistry and Nutrition at Trinity College. His research with the talented group of scientists and clinicians that he led has had a substantial impact on our understanding of folate metabolism, mechanisms of its catabolism and deficiency. His research established the leading theory of folate involvement with vitamin B12 in the pathogenesis of vitamin B12 neuropathy. He helped to establish the normal daily intake of folate and the increased requirements needed either in food or as a supplement before and during pregnancy to prevent neural tube defects. He also suggested a dietary supplement of vitamin B12 before and during pregnancy to reduce the risk of neural tube defects. It would be an appropriate epitaph if fortification of food with folic acid became mandatory in the UK and Ireland, as it is in over 70 other countries.     

Comparison of the canine tissue distribution of digoxin after acute and chronic administration: implications for digitalis therapy

Digoxin is often used as an antiarrhythmic and inotropic agent. It produces significant neuroexcitatory responses that influence both its therapeutic and toxic effects. Patients receiving digoxin can be separated into 2 groups: those who receive it acutely and those who receive it chronically. The therapeutic and toxic responses to digoxin vary between these groups. The neural tissue distribution of digoxin was compared in dogs after both acute and chronic injections. Acute administration of digitalis in this study was associated with preferential uptake of digoxin into peripheral sympathetic nerves. Chronic administration was associated with continued selective uptake into the central nervous system despite decreasing serum levels. Therefore, acute (experimental or suicidal) or chronic (maintenance) digoxin administration produces different neural responses. The peripheral sympathetic nervous system will be the primary area of interaction with acute digoxin administration and the central nervous system will have a greater involvement with chronic digoxin administration. Our results indicate that the uptake of digoxin into the peripheral nervous system and central nervous system depends upon the duration of digoxin administration. The time course of digoxin accumulation influences both its therapeutic and toxic actions.     

Neuropathic joint disease (Charcot joints) in Waldenström's macroglobulinemia with amyloidosis

A 51 year old man with a monoclonal elevation of serum macroglobulin, generalized osteoporosis and infiltration of the marrow with lymphocytoid plasma cells is described. He also had nephrotic syndrome due to para-amyloid deposition and severe peripheral neuropathy. A dramatic sequela of the neuropathy, and not previously reported in plasma cell dyscrasias, was severe neuropathic joint destruction (Charcot joints).     

Effects of interruption of the enterohepatic circulation of bile acids on the transport of very low density-lipoprotein triglycerides

An increase in plasma very low density lipoprotein-triglycerides (VLDL-TG) is seen frequently during treatment with bile acid-binding resins. The purpose of this study was to determine whether this increment in VLDL-TG is due mainly to an increase in synthesis of VLDL, or to an enhanced catabolism. Three types of patients were studied: (1) 7 normotriglyceridemic subjects. (2) 4 obese patients, and (3) 9 hypertriglyceridemic patients. Before treatment they underwent a study of VLDL-TG kinetics that employed multicompartmental analysis of specific activity curves following injection of ³H-glycerol. The patients were then treated with a bile acid-binding resin, either cholestyramine or colestipol, for several weeks to several months. At the end of the treatment period, they were readmitted to the hospital for a second study of VLDL-TG kinetics. The patients showed a variable response to resin therapy. Many had an increase in concentrations of VLDL-TG, but others had no change or even a slight decrease. However, analysis of the data showed a high correlation between change in production rates of VLDL-TG and change in concentration. Also, when the data for the 20 patients were combined, there was a statistically significant increase in both synthetic rates and concentrations of VLDL-TG; in contrast, the fractional catabolic rate (FCR) was unchanged by therapy. Therefore, our data show that when treatment with bile acid sequestrants causes an increase in plasma VLDL-TG, the increase is due to an increment in production and not to a decrease in catabolism.     

Bile sequestrant therapy alters the compositions of low-density and high-density lipoproteins.

Bile sequestrant resins are used to lower the levels of low-density lipoprotein cholesterol in plasma because this may ameliorate atherosclerosis. Yet the levels and compositions of all the lipoproteins may affect atherogenesis. We have previously shown alterations in very-low-density lipoprotein (VLDL) metabolism in response to one of these agents, colestipol HCl. Here we report the effects of colestipol on the composition of low-density and high-density lipoproteins (HDL). Eighteen subjects with type II hyperlipoproteinemia were studied during baseline, diet, and drug periods lasting 2–3 mo. Lipoprotein lipids and apolipoproteins A-I, A-II, and B were measured, and indices of lipoprotein composition were calculated. Colestipol produced significant changes in all lipoproteins. VLDL-triglyceride rose transiently, the magnitude and duration both correlated with pretreatment values (r = 0.84 and 0.76, respectively, both p < 0.001). Low-density (density 1.006–1.063) lipoprotein cholesterol fell below the dietary mean by 28%, but low-density triglyceride fell by only 13% and apolipoprotein B by 17%. Thus, low-density lipoprotein cholesterol/apolipoprotein B ratios decreased (1.9 versus 1.6, p < 0.005). Low-density and very-low-density cholesterol/apoprotein B ratios also decreased significantly. Thus, all the apolipoprotein-B-containing lipoproteins had less cholesterol relative to apolipoprotein B. High-density lipoprotein cholesterol remained unchanged, although transient increases in high-density lipoprotein triglyceride occurred. Apolipoprotein A-I levels remained constant (∼105 mg/dl), but A-II levels fell (from 55 to 45 mg/dl); therefore, $\text{A-I}\text{A-II}$ ratios rose (2.0 versus 2.5, p < 0.001). Thus, alterations in the composition of both high-density and low-density lipoproteins occurred. Colestipol produced changes in lipoprotein composition that may have effects on atherogenesis independent of its effects on lowering plasma cholesterol. Further studies will be needed to determine whether or not these changes are beneficial.     

Normocholesterolemic tendon xanthomatosis with overproduction of apolipoprotein B

This report describes a 46-yr-old man with normocholesterolemic tendon xanthomatosis. He had severe bilateral xanthomas of Achilles tendons and small lesions on patellar tendons; biopsy of the latter revealed a fibroxanthoma of high cholesterol content. He did not have clinical evidence of atherosclerotic disease. The patient's total cholesterol (TC) and triglycerides (TG) were 245 and 258 mg/dl, respectively. LDL-TC was 168 mg/dl and HDL-TC was 32 mg/dl. VLDL consisted mainly of small particles (S_f^o 20–100) which were unusually rich in apolipoproteins B and E (and low in apo Cs). Plasma LDL-apo B was not increased (85–120 mg/dl), but VLDL-apo B was distinctly elevated (58 mg/dl). The synthesis rate of apoLDL (29.9 mg/kg/d) was increased markedly compared to a matched control (13.9 mg/kg/d) and to a patient with familial hypercholestrolemia (15.9 mg/kg/d). The concentration of apoLDL in our patient was not increased; this was because of an associated high FCR (0.484 day^?1). His HDL was relatively low in TC but high in TG, which caused an increase in HDL_2b. The patient's xanthomata may have been the result of an overproduction of apo B possibly combined with a defect in HDL metabolism.     

Altered HDL subclasses in endogenous hypertriglyceridemia are not affected by weight reduction

Reduction of body weight is commonly used to decrease the plasma lipids of patients with primary endogenous hypertriglyceridemia, but the effects of stabilized weight reduction on lipoprotein compositions and distribution are not well known. Since lipoprotein structures are perhaps as important in normal and abnormal metabolism and atherogenesis as are the levels of lipoproteins, we examined the effects of weight loss on the plasma concentrations, compositions, and ultracentrifugal flotation properties of plasma lipoproteins. Nine patients (eight males, one female) with endogenous hypertriglyceridemia and low high-density lipoprotein (HDL)-cholesterol levels who were approximately 130% of ideal body weight were studied during two dietary periods (basal and low weight). Subjects consumed an isocaloric diet for 5 weeks consisting of approximately 15% protein, approximately 45% carbohydrate, approximately 40% fat, approximately 500 mg/d cholesterol, P/S ratio 0.43 (basal), followed by a hypocaloric diet of the same composition, which was eaten for 16 to 52 weeks, until the desired weight was lost (9.6 +/- 3.6 kg). Then patients continued to eat a diet of the same composition lower in calories but sufficient in quantity to maintain their new lower body weights for the final 5 weeks (low-weight period). The last weeks of the basal and the low-weight periods were spent in a metabolic ward. Thus, high and low body weights were known to be stable for at least 5 weeks. Fasting (12 to 14 hours) plasma total triglycerides decreased in all patients (from 328 +/- 204 mg/dL at basal to 185 +/- 77 mg/dL at low weight, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)