Permanent tunneled silicone central venous catheters for autologous PBPC harvest in children and young adults.
(25/502)
Children with high risk malignancies are usually given permanent (Hickman-type) tunneled silicone rubber central venous catheters (silicone CVCs) for the administration of chemotherapy. In the past, these children received an additional short-term polyurethane dialysis CVC for stem cell apheresis. To avoid placement of an additional short-term CVC, we started in 1995 to use pre-existing silicone CVCs for PBPC harvests. From May 1996 to February 1999 we evaluated 165 harvests in 37 children and 14 young adults (16-28 years) treated with high-dose chemotherapy and stem cell support, comparing CD34+ cell harvest efficiency, catheter tolerability, and complications in three different approaches to vascular access. Pre-existing silicone CVCs (64%) or peripheral venous cannulae (15%) were the first choice for venous access. Only when these failed were polyurethane CVCs (21%) used. No significant difference was seen between these three groups, even after dividing the silicone CVC group (105 harvests in 32 patients) into three subgroups according to weight and age. The most frequent problems were citrate toxicity (n = 33), mechanical obstruction inside (n = 9) and outside the cell separator (n = 2), decreased draw line flow in silicone CVCs (n = 7), decreased draw line flow in peripheral venous cannulae (n = 6), and one occlusion in a polyurethane CVC. Pre-existing CVCs and peripheral venous cannulae functioned efficiently when used as a draw line in 79% of the apheresis procedures without significantly reducing single harvest efficiency or catheter tolerability. Consequently, the risks and costs associated with the placement of a dialysis CVC could be avoided in the majority of cases. Bone Marrow Transplantation (2000) 26, 781-786. (+info)
Early neonatal hypocalcaemia.
(26/502)
In our hospital early neonatal hypocalcaemia is now the major cause of low serum calcium in the neonatal period. Over a 2-year period, only 2 cases of hypocalcaemic convulsions were seen in a total of 8700 deliveries, though 51 infants had early neonatal hypocalcaemia. All sick low birth-weight infants should have daily serum calcium estimations carried out. Calcium supplements should be considered if symptoms of hypocalcaemia are present. (+info)
Clinical applications of the continuous flow blood separator machine.
(27/502)
The NCl/IBM or Aminco Continuous Flow Blood Separator Machine is a safe apparatus for the selective removal or exchange of either packed red blood cells, leucocyte-rich or platelet-rich layers or plasma. Abnormal fractions from any of these layers may be collected and discarded. Normal constituents may be collected for therapeutic uses. The wide scope of its applications includes important uses in clinical immunology: temporary provision of good leucocytes or platelets; harvesting of immune leucocytes (preparation of transfer factor at up to 10 units per harvest); removal of cryo- or macro-globulins, immune complexes or blocking factors; replacement therapy for antibody or complement deficiencies. Examples are given of such uses together with some of the medical problems so far encountered. (+info)
Recognition and management of hungry bone syndrome--a case report.
(28/502)
Hungry bone syndrome (HBS) following successful parathyroid surgery is a well described phenomenon. However, few studies have clearly addressed this syndrome or looked at the outcome of perioperative management. We report a case of HBS following successful parathyroid surgery. The perioperative management is discussed and literature pertaining to this interesting case is reviewed. (+info)
Management of disturbed calcium metabolism in uraemic patients: 1. Use of vitamin D metabolites.
(29/502)
Chronic renal failure is characterized by diminished synthesis of, and resistance to, the active vitamin D metabolite 1,25-dihydroxy-vitamin D3 (1,25(OH)2D3, calcitriol). Calcitriol results from the biotransformation of the precursor 25-hydroxy-vitamin D3 (25(OH)D3) to 1,25(OH)2D3. 25(OH)D3 is synthesized in the liver, and 1alpha-hydroxylase, the rate-limiting enzyme for its biotransformation into the most active metabolite, 1,25(OH)2D3, is located in the kidney. The regulation of 1alpha-hydroxylase in renal failure is not well known. Recent work indicates that, in contrast to previous opinion, 1alpha-hydroxylase is predominantly expressed not in the proximal tubule but in the distal tubule [1]. In vivo, the main stimulatory signal is presumably parathyroid hormone (PTH) and the main inhibitory signal hyperphosphataemia. Both signals are altered in renal failure. There is also evidence that the renal 1alpha-hydroxylase becomes substrate-dependent in patients with renal failure. This means that a higher concentration of the precursor 25(OH)2D3 will result in a higher rate of transformation into the active metabolite 1,25(OH)2D3 in renal patients. Calcitriol is not exclusively synthesized in the kidney, but may also be synthesized in extra-renal tissues, e.g. activated monocytes/macrophages [2], particularly in granuloma [3] as shown by anephric uraemic patients who develop hypercalcaemia and elevated calcitriol concentrations when sarcoidosis [4] or tuberculosis [5] supervenes. On the other hand, calcitriol is less effective in uraemia. This may be to some extent due to diminished expression of vitamin D receptors [6], particularly in parathyroid glands when they undergo nodular transformation [7], but there may also be resistance to calcitriol at the post-receptor level [8]. In a series of elegant experiments [9,10], calcitriol resistance has been related to disturbed genomic effects of active vitamin D because the interaction of the vitamin D receptor ligand complex with vitamin D-responsive elements (VDREs) upstream of vitamin D-regulated genes was disturbed by the action of low molecular weight substances in uraemia, which have not been completely characterized. The role of genetically determined polymorphisms of the vitamin D receptor in the genesis of disturbed calcium metabolism of renal failure is currently unclear. (+info)
The importance of the ligation of the inferior thyroid artery in parathyroid function after subtotal thyroidectomy.
(30/502)
We prospectively studied the effects of the ligation of the inferior thyroid artery (ITA) on postoperative hypoparathyroidism in 48 patients who underwent functional subtotal thyroidectomy. Patients were randomized into two groups: A, with bilateral ligation of the ITA and B, without ligation of the ITA. Parathyroid function was checked preoperatively and after surgery by clinical examination and measurement of total calcium, intact PTH, urinary calcium, and AMPc. RESULTS: A significant incidence of postoperative hypocalcemia occurred: 17% in group A and 13% in B on the 4th postoperative day. Six months later, the incidence was 5% in Group A and 0% in Group B. These differences were not statistically significant between the two groups, and neither were any of the other clinical and laboratory observations. CONCLUSION: The ligation of the ITA was not an important causal factor for the occurrence of postoperative hypocalcemia after subtotal thyroidectomy. (+info)
Hypocalcaemia in severe meningococcal infections.
(31/502)
AIM: To determine the incidence of hypocalcaemia in critically ill children with meningococcal disease. METHODS: In a prospective cohort study, 70 of 80 patients admitted consecutively with a clinical diagnosis of meningococcal disease to intensive care had measurements of total and ionised calcium on admission. Parathormone and calcitonin were measured in a proportion of the children. RESULTS: Total and ionised calcium concentrations were low in 70% of the children. There was a weak relation of calcium concentration to the volume of blood derived colloid which had been given, but a good relation to disease severity, where sicker children had lower calcium concentrations. Although the parathormone concentration was higher in children with lower calcium concentrations, some children had low ionised calcium concentrations, without an increase of parathormone concentration. Serum calcitonin concentration was not related to calcium concentrations. CONCLUSION: Hypocalcaemia is common in meningococcal disease. (+info)
Multicenter phase I-II trial of docetaxel, cisplatin, and fluorouracil induction chemotherapy for patients with locally advanced squamous cell cancer of the head and neck.
(32/502)
PURPOSE: We conducted a phase I-II, multi-institutional trial to determine the maximum-tolerated dose (MTD) of cisplatin in an induction chemotherapy regimen of docetaxel, cisplatin, and fluorouracil for squamous cell cancer of the head and neck (SCCHN) and to determine the safety, tolerability, and efficacy of the regimen at MTD. PATIENTS AND METHODS: A total of 43 patients with previously untreated, locally advanced, curable SCCHN were entered. Overall, 29 patients (67%) had N2 or N3 nodal disease and nine (21%) had T4 primary tumors. All patients received docetaxel 75 mg/m(2) on day 1; cisplatin at 75 (level I) or 100 (level II) mg/m(2) on day 1; and a continuous fluorouracil infusion at 1,000 mg/m(2)/d on days 1 through 4. Patients were treated with prophylactic antibiotics on days 5 through 15. Cycles were repeated every 21 days for a total of three cycles. Patients then received definitive therapy based on institutional preferences. RESULTS: Thirteen patients were treated at level I, and 30 patients were treated at level II. All 43 patients were assessable for toxicity. There were no major differences in toxicity between level I and level II. Cisplatin-associated grade 3 or 4 hypomagnesemia or hypocalcemia occurred in 13 (30%) and hearing loss in two patients (5%). Grade 3 or 4 neutropenia was observed in 41 patients (95%) and febrile neutropenia occurred in eight (19%). There was one serious infection (2%). There were 17 (40% [95% confidence interval [CI], 25% to 56%]) clinical complete responders (CR), 23 (54% [95% CI, 39% to 69%]) partial responders (PR), one (2%) with no change, and two (5%) unassessable patients. Major responses (CR, PR) were observed in 40 (93% [95% CI, 81% to 99%]) patients. Primary site CR was documented in 24 (54%) of patients. Postchemotherapy primary site biopsies were performed in 25 patients (58%) and pathologically negative biopsy was obtained in 11 (92%) of 12 primary site clinical CRs and seven (54%) of 13 with PR or no change. Overall, negative biopsies were obtained in 18 patients (72%). CONCLUSION: TPF induction chemotherapy can be delivered safely with a cisplatin dose of 100 mg/m(2) in previously untreated patients with SCCHN. The regimen is associated with a high rate of primary site clinical and pathologic CRs. Phase III comparison with cisplatinum and fluorouracil chemotherapy is warranted. (+info)