Time course of muscle atrophy and recovery following a phenol-induced nerve block

Clinically, phenol is used often as a neurolytic agent to treat pain and spasticity. The purpose of this study was to examine the time course of denervation and recovery in several hindlimb muscles following application of a 5% aqueous solution of phenol to the sciatic nerve. Phenol was applied to the sciatic nerve of adult female rats either by intraneural or perineural injection. Axonal degeneration was evident within the sciatic nerve 2 days following phenol application, although variable amounts of damage were observed. By 2 weeks, the soleus and tibialis anterior had atrophied to 63% and 51% of control. Reinnervation of hindlimb muscles occurred between 2 and 4 weeks following the nerve block. Following denervation, the soleus became slower in that all of the fibers expressed the slow myosin heavy chain (MHC). At 5 months, maximum tension of the soleus was 74% of control and the muscle consisted of more fast fibers on average, some of which expressed IIx MHC. These data suggest that 5% phenol causes an injury to the nerve that is more severe than a crush injury, and that reinnervation of denervated muscles may be by motoneurons other than those that originally innervated the muscles. © 1996 John Wiley & Sons, Inc.     

Calcium mass transfer in peritoneal dialysis patients using 2.5 mEq/l calcium dialysate.

Standard peritoneal dialysate has a relatively high calcium concentration of 3.5 mEq/l. Peritoneal dialysis patients thus gain calcium from the dialysate which contributes to the risk of hypercalcemia. Dialysate with 2.5 mEq/l calcium is now available. Theoretically, using dialysate with this calcium content, calcium transfer should be negative (from the patient into the dialysate) when the patient is hypercalcemic, and positive when the patient is normocalcemic or hypercalcemic. Thus, 2.5 mEq/l calcium dialysate may allow larger doses of calcium carbonate to be prescribed. We compared calcium mass transfer (CMT) in 17 stable peritoneal dialysis patients using 3.5 and 2.5 mEq/l calcium dialysate. A solution of 2.05 l, 1.5 g/dl dextrose was dwelled for 4 hours. Calcium was measured in the drained dialysate and serum (total and ionized). Mean CMT was 0.7 +/- 0.5 mEq/exchange using 3.5 mEq/l calcium dialysate and -0.9 +/- 0.9 mEq/exchange using 2.5 mEq/l calcium dialysate (p less than 0.0001). At the time of the CMT studies, the mean serum ionized calcium levels were identical for the two groups (2.6 mEq/l). CMT correlated inversely with serum total calcium, serum ionized calcium, and drained dialysate volume. During hypercalcemia calcium transfer was from the dialysate to the patient when 3.5 mEq/l calcium dialysate was used, but from the patient to the dialysate when 2.5 mEq/l calcium dialysate was used. We conclude that 2.5 mEq/l calcium dialysate is effective in removing calcium and will be helpful in preventing hypercalcemia when large doses of oral calcium compounds are prescribed as a phosphate binder.     

A blinded, randomized, multicenter study of an intravenous Staphylococcus aureus immune globulin.

OBJECTIVES: Very low birth weight (VLBW) infants are vulnerable to nosocomial infections and subsequent morbidity; including infections caused by Staphylococcus aureus: 85% of nosocomial S. aureus infections are caused by capsular polysaccharide (CPS) types 5 and 8. Altastaph is a polyclonal investigational human immunoglobulin G (IgG) with high levels of opsonizing S. aureus CPS types 5 and 8 IgG. METHODS: A Phase 2 clinical trial to assess the safety and kinetics of Altastaph in VLBW infants. Neonates in this multicenter study were randomized to receive two identical 20 ml/kg i.v. infusions of either 0.45% NaCl placebo or 1000 mg Altastaph/kg. Each infant was followed for 28 days after the second infusion or until discharge. Serum S. aureus CPS types 5 and 8 IgG levels were measured preinfusion and at various times after each infusion. RESULTS: Of 206 neonates, 158 received both infusions. Adverse events were similar in the two treatment groups. Six subjects (3% in each group) discontinued owing to an adverse event. Geometric mean anti-type 5 IgG levels were 402 and 642 mcg/ml 1 day following infusion of the first (day 0) and Second (day 14) doses, respectively, in neonates < or =1000 g and slightly higher in neonates 1001 to 1500 g. Trough levels before second infusion were 188 mcg/ml. Type 8 IgG levels were similar. Geometric mean IgG levels among placebo recipients were consistently <2 and <5 mcg/ml for types 5 and 8 in both weight groups. Three episodes of S. aureus bacteremia occurred in each arm. CONCLUSIONS: Infusion of Altastaph in VLBW neonates resulted in high levels of specific S. aureus types 5 and 8 CPS IgG. The administration of this anti-staphylococcal hyperimmune globulin was well tolerated in this population.     

Carers, ethics and dementia: a survey and review of the literature.

BACKGROUND: Much has been written on ethical issues in dementia, but usually from the point of view of the various professionals involved. Whilst there has been an increasing amount of interest in the psychosocial problems that face the carers of people with dementia, the ethical nature of some of these problems has largely been ignored. OBJECTIVE: To review the literature on ethical issues in dementia from the perspective of the main, non-professional carers of people with dementia. METHOD: A systematic literature search using Medline, Clinpsych and CINAHL databases between 1982 and 2000. A pilot study of carers. RESULTS: The lay perspective provides both a wide variety of issues and unique approaches. Although in the literature quantitative research answers some questions, it is qualitative research that deepens our understanding of the issues from the perspective of carers. CONCLUSION: It is particularly qualitative research that brings out the ethical issues for carers, which tend to be more varied than the ethical issues raised in the professional literature. Awareness of such issues could inform and shape the support given to carers.     

Elevated fibroblast growth factor-23 in hypophosphatemic linear nevus sebaceous syndrome

We report on an adolescent who experienced the onset of linear nevus sebaceous syndrome (LNSS) prior to 1 year of age. At 7 years of age he was diagnosed to have hypophosphatemic rickets. He was suboptimally controlled with phosphate and calcitriol treatment and sustained numerous insufficiency fractures ipsilateral to the linear sebaceous nevus. Fibroblast growth factor-23 (FGF-23), the phosphaturic peptide, was elevated in the plasma. Treamtent with the somatostatin agonist, octreotide, and excision of the nevus were followed by normalization of FGF-23 and clinical improvement. The patient also had hyperimmunoglobulinemia E, which responded to octreotide and surgery. We speculate that in some patients with LNSS there may be more than one mediator of hypophosphatemia and that FGF-23 is the mediator of hyperphosphaturia in this and other hypophosphatemic syndromes.