[Lithium, a potentially dangerous drug]. / Lithium, een potentieel gevaarlijk geneesmiddel.

Two patients with a bipolar disorder, a woman aged 56 and a woman aged 68, who had used lithium for more than 30 years, were seen with side effects from this medication. Both patients were treated by their general practitioner and had not visited a psychiatrist for many years. The first patient had a chronic lithium intoxication with cerebellar signs and eventually coma, diabetes insipidus, hyperthyroidism, hyperparathyroidism and psoriasis. After 6 weeks of treatment in the intensive-care unit she made a good recovery. The second patient had several lithium side effects. She was diagnosed with diabetes insipidus, hyperparathyroidism due to a parathyroid adenoma, hypothyroidism and a sick-sinus syndrome. A pacemaker was implanted 4 years earlier. The adenoma was surgically removed. After other medication was tried, the patient was once again given lithium, on which she was able to function well. The first patient had lithium concentrations above the therapeutic value for several years and both patients experienced a delay before their signs and symptoms were attributed to lithium. Lithium treatment should be monitored by an experienced psychiatrist.

Rapid, arteriovenous graft failure due to intimal hyperplasia: a porcine, bilateral, carotid arteriovenous graft model.

BACKGROUND: The loss of patency constitutes the major complication of arteriovenous (AV) polytetrafluoroethylene hemodialysis grafts. In most cases, this graft failure is due to intimal hyperplasia at the venous outflow tract, including proliferation of vascular, smooth muscle cells and fibroblasts with deposition of extracellular matrix proteins. Thus far, procedures developed for improving patency have proven unsuccessful, which can be partly explained by the lack of relevant animal models. For this purpose, we developed a porcine model for AV graft failure that will allow the assessment of promising therapeutic strategies in the near future. MATERIALS AND METHODS: In 14 pigs, AV grafts were created bilaterally between the carotid artery and the jugular vein using expanded polytetrafluoroethylene. Two, 4 or 8 weeks after AV shunting, the grafts and adjacent vessels were excised and underwent histologic analysis. RESULTS: From 2 weeks onwards, a thick neo-intima developed at the venous anastomosis, predominantly consisting of alpha-actin-positive vascular smooth muscle cells (VSMC). Intimal area increased over time, coinciding with a decreased graft flow. Grafts remained patent for at least 4 weeks. At 8 weeks, patency rates declined to less than 50% due to thrombus formation superimposed on progressive neo-intima formation. CONCLUSIONS: Implantation of an AV graft between the carotid artery and jugular vein in pigs causes a rapid neo-intimal response, accompanied by a loss of patency of 50% at 8 weeks after surgery. This model offers a suitable tool to study local interventions aimed at the improvement of AV graft patency rates.

Folic acid reverts dysfunction of endothelial nitric oxide synthase.

5-methyltetrahydrofolate (MTHF), the active form of folic acid, has been reported to restore NO status in hypercholesterolemic patients. The mechanism of this effect remains to be established. We assessed the effects of L- and D-MTHF on tetrahydrobiopterin (BH(4))-free and partially BH(4)-repleted endothelial NO synthase (eNOS). Superoxide production of eNOS and the rate constants for trapping of superoxide by MTHF were determined with electron paramagnetic resonance using 5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO) as spin trap for superoxide. NO production was measured with [(3)H]arginine-citrulline conversion or nitrite assay. The rate constants for scavenging of superoxide by L- and D-MTHF were similar, 1.4 x 10(4) ms(-1). In BH(4)-free eNOS, L- and D-MTHF have no effect on enzymatic activity. In contrast, in partially BH(4)-repleted eNOS, we observe a 2-fold effect of MTHF on the enzymatic activity. First, superoxide production is reduced. Second, NO production is enhanced. In cultured endothelial cells, a similar enhancement of NO production is induced by MTHF. In the present study, we show direct effects of MTHF on the enzymatic activity of NO synthase both in recombinant eNOS as well as in cultured endothelial cells, which provides a plausible explanation for the previously reported positive effects of MTHF on NO status in vivo.

Intraocular lens implantation in severely mentally and physically handicapped patients.

Posterior chamber intraocular lenses (PC-IOL) were implanted in 42 eyes of 24 severely mentally and physically handicapped patients, and the results were analyzed in comparison with implants in conventional patients. The patient eyes included in this study were 21 eyes of 13 severely mentally retarded patients, 19 eyes of 10 Down's syndrome patients, and 2 eyes of a patient suffering from mitochondrial encephalomyopathy. Surgeries had been performed under general anesthesia and resulted in significant improvement in vision and quality of life. Severe postoperative complications occurred in one of the eyes of two patients. However, the fellow eye of these patients, which also received a PC-IOL implantation, showed an uneventful postoperative course. The present study indicated that cataract surgery with PC-IOL in patients with severe mental and physical handicaps should be considered as an appropriate and promising application in spite of the various technical difficulties in the pre- and postoperative management of these patients. It is stressed that proper calibration of IOL power immediately before surgery under general anesthesia and small incision techniques are essential for a successful operation in patients with severe mental and physical handicaps.

Metallic expanding biliary stents in malignant obstruction. Cases with stent in stent.

We reviewed a total of 13 stent (Gianturco-Rosch biliary Z-stent) placements in 11 patients with biliary obstruction due to malignancy and report the cases treated with the stent-in-stent technique for treatment of stent occlusion due to tumor ingrowth. Causes of biliary obstruction included cholangiocarcinoma (four cases), hepatic hilar metastasis of gastrointestinal carcinoma (five cases), and pancreatic carcinoma (two cases). After transient percutaneous transhepatic biliary drainage (PTBD), the stents were successfully inserted by transhepatic route in all patients without any serious complication that needed further surgical intervention. Almost all patients were freed from the external PTBD tube about a week after stent placement and discharged from the hospital with improvement in quality of life as well as normal serum bilirubin levels. The technical advantages of stent placement include ease of insertion and the ability to drain both right and left biliary systems from a single transhepatic route by arranging the stents in a variety of configurations. Furthermore, it provides a second chance of stent placement when the previous stent has been occluded by tumor ingrowth.