Eilif Dahl

The effect of parathyroid hormone (PTH) and 24,25-dihydroxy-vitamin D3 on adenylyl cyclase of iliac crest biopsies: Diagnostic and prognostic tool for evaluation and treatment of uremic patients

The bone adenylyl cyclase (AC) complex of iliac crest biopsies of normals, uremic patients and subjects with primary hyperparathyroidism (PrHPT) have been investigated. Bone resorption (RS) in uremic patients appears to be related partly to increased serum parathyroid hormone (s-PTH) levels and to netto PTH-stimulated AC (net PTH-AC) and partly to the uremic condition (as estimated by s-Creatinine) per se. Serum PTH is able to completely desensitize the PTH dependent bone AC in normals in vivo, but only partially in uremic patients. In patients with PrHPT, the bone AC appears to be inert to homologous desensitization. Positive aluminum staining is associated with blunted CT-responsive and low basal AC. In the combined group of normals and uremic patients, net PTH-AC is (as predicted from human in vitro data and the rat model) inversely related to serum 24,25-diOH-D3. Net PTH-AC, when corrected for s-24,25-diOH-D3 levels, correlated well with RS. The described action of 24,25-diOH-D3 presents a clearly defined rationale for the use of 24,25-diOH-D3 concurrently with 1,25-diOH-D3 to treat renal osteodystrophy: By administering 1,25-diOH-D3, s-Ca2+ and s-PTH will normalize and consequently net PTH-AC diminish. 24,25-diOH-D3 is then believed to further reduce net PTH-AC and RS. A concomitant alleviation of the uremic condition would eventually ensure the fastest possible restoration of bone structure and function.

A preliminary study of aluminium in serum and other human materials in subjects from different areas of Norway.

It is well known that aluminium accumulates and causes toxic effects in several tissues in patients who have greatly impaired kidney function (Ganrot, 1986). While such patients are exposed via the dialysis fluid and phosphate binding agents, the major sources of aluminium for healthy individuals are via food and aluminium cookware. The contribution from drinking water is usually very small and less than 10% of the total intake of aluminium. However, due to the use of aluminium sulphate in water works and acid rain in the southern part of Norway, the level of aluminium in drinking water in certain areas has increased up to 1,000 fold (1-2 mg/L).

Implementation of Automated External Defibrillators on German Merchant Ships

The outcome of sudden cardiac arrest depends on the “chain of survival” 1 : 1. Immediate recognition of cardiac arrest and activation of the emergency response system 2. Early CPR with an emphasis on chest compression 3. Rapid defibrillation 4. Effective advanced life support 5. Integrated postcardiac arrest care Automated external defibrillators (AEDs) have proven valuable in out‐of‐hospital settings close to definitive care institutions like airports, casinos, and cruise ships—sites with a high density of both potential victims and resuscitators. 2–4 In contrast, AEDs save very few lives in residential units such as private homes or apartment complexes. 5 The benefit of AEDs in remote areas without available qualified medical follow‐up, such as most merchant ships, is unknown and controversial. 6 The Federal Republic of Germany has decided that AEDs with EKG display and transmission means must be present in all German‐flagged merchant vessels in intermediate and long‐distance trade by the end of 2012. Because there is only one German‐registered cruise ship and most ferries are exempt from this rule, nearly all AEDs will be on ships … Corresponding Author: Professor Eilif Dahl, MD, MHA, PhD, Section for Pediatric Surgery, Department for Liver, Gastrointestinal and Pediatric Surgery, Oslo University Hospital, PO Box 4950, Nydalen, Oslo 0424, Norway. E‐mail: eilifdahl{at}hotmail.com

Chronic renal failure: diagnostic measures before parathyroidectomy.

To investigate whether conventional criteria suffice to differentiate between hyperparathyroid and aluminum (Al)-related bone disease, we obtained bone biopsies from 7 patients with chronic renal failure (CRF) at the time of PTX and 3.5-36 months later. All had hypercalcemia and elevated mid-region parathyroid hormone levels and 3 had bone pain at PTX. Bone histomorphometry revealed that 5 patients had hyperparathyroid bone disease at PTX, while 2 had osteomalacia and skeletal Al deposits. Retrospective determination of intact PTH showed normal levels at PTX in the latter two. PTX effectively reduced all indices of parathyroid hyperactivity, but the two patients with Al-related bone lesions did not improve clinically nor histologically after PTX. Intact PTH and/or bone biopsy prior to PTX could have deterred surgery in those with Al-related bone disease.

Aluminium metabolism in chronic renat failure: Environmental influences and regional differences in Norway

Many aspects of Al metabolism in chronic renal failure are poorly understood. A longitudinal study of serum Al concentrations in predialysis patients and healthy control subjects revealed very high values during the autumn of 1984 and 1985. Renal Al clearance was low during the autumnal spike in serum Al but increased substantially when the serum Al concentration declined. A second study confirmed that by using citric acid as a chelator, the gastrointestinal absorption of Al from Al(OH)3 may be considerably augmented as reflected by increases in both serum Al concentrations and renal Al clearance. The individual differences in Al absorption in this study were large.The first study suggests the existence of an unidentified environmental factor, possibly water borne, with profound effects on Al absorption and excretion. The citric acid/Al(OH)3 experiment suggests that the existence of such a factor is likely. The implications of these results are not known.A histomorphometric study of bone biopsies from 138 hemodialysis and 66 predialysis patients without clinical evidence of Al related disease, revealed Al deposits after staining with aurin tricarboxylic acid in 78% of the biopsies from the former and 24% of the latter patients. Serum Al concentrations did not differ between predialysis and hemodialysis patients with Al positive biopsies. Stratification of the hemodialysis patients, who came from all parts of Norway, revealed that patients living in regions with slightly Al contaminated drinking water (Al <30 μg/L) had lower serum Al concentrations than patients from regions with highly contaminated water (Al >100 μg/L). The prevalence of Al-positive biopsies was the same in both regions. Patients with Al-positive biopsies did not differ in serum Al level from those with Al-negative biopsies within the same region. Predialysis patients with Al-positive biopsies had significantly higher serum Al levels than predialysis patients with Al negative biopsies.Stainable Al deposits are commonly found in the bone of patients with chronic renal failure. Cross-sectionally obtained serum Al concentrations do not reflect the prevalence of stainable bone Al in renal patients but are related to the degree of Al contamination of water of the region.

Pretransplant Parathyroidectomy in Renal Failure: Effects on Bone Histology and Aluminum Deposits During Dialysis and after Kidney Transplantation

Using repeat bone biopsies, we studied whether 1) subtotal parathyroidectomy (PTX) enhances aluminum (Al) deposition in bone and 2) whether pretransplant PTX affects Al removal from bone after kidney transplantation. Twenty-four kidney graft recipients, 10 subjected to PTX 9-44 months prior to transplantation and 14 controls matched for dialysis duration, had bone biopsies taken at transplantation. Serum calcium and parathyroid hormone levels had decreased after PTX in all 10. At transplantation, eroded bone surface was lower in PTX-recipients, while extent of Al-stained bone surface and prevalence of symptomatic Al-related bone disease were similar in both groups (PTX: 2/10; non-PTX: 4/14). Hence, PTX did not enhance accumulation of stainable bone Al nor increase prevalence of clinical bone disease during dialysis. Fourteen (7 PTX) recipients with functioning grafts had a second biopsy 12 months after transplantation. Symptomatic Al-related bone disease was cured regardless of pretransplant PTX, and Al-stained surface had decreased in all but one (PTX) recipient.