Catecholamine uptake, accumulation, and release in acute porphyria

Hypertension and tachycardia are well known features of acute porphyria and have been shown to be related to increased circulating catecholamines. The mechanism by which circulating catecholamines are increased was studied using the isolated perfused rat heart and human platelets as a model of adrenergic neuronal function. It was found that neither delta-aminolevulinate (ALA) nor porphobilinogen (PBG) blocked uptake or caused release in the isolated perfused rat heart. Platelets from six patients with acute prophyria, three in remission and three latent, with matching normal controls were studied with regard to their uptake of [(3)H]norepinephrine in the presence of ALA or PBG. It was found that ALA and PBG significantly reduced uptake and accumulation of [(3)H]-norepinephrine in patients with acute porphyria; however, no similar reduction in uptake and accumulation was observed in the platelets of normal controls. Therefore, it appears that there is a latent defect in the catecholamine uptake and (or) accumulation of platelets of patients with acute prophyria which only manifests itself in the presence of ALA or PBG. If platelet uptake serves as a model of adrenergic neuron uptake, this suggests that elevated circulating catecholamine levels during acute attacks of acute porphyria are caused at least partially by blockade of re-uptake into the sympathetic neurons.     

A bandwidth enhancement technique for mobile handset antennas using wavetraps

A novel technique for enhancing the impedance bandwidth of wireless terminal antennas is presented. By introducing resonant short circuit transmission lines to the long sides of the chassis edges, an effective electrical shortening of the terminal ground plane is achieved. This effect has been used to realize terminal ground planes with resonant lengths at high frequencies, such as GSM 1800/1900 MHz or UMTS 2 GHz, thereby extending the impedance bandwidth. The proposed technique has been validated by simulations and measurements. Three typical applications are presented where the introduction of wavetraps improves the bandwidth and/or in-band performance.     

The presence of genital mycoplasmas in women of reproductive age

Although 5-HT1 and 5-HT2 receptor activity is known to influence copulation, the effects of 5-HT3 receptor-selective drugs on sexual activity have yet to be systematically studied. The following experiments investigated the effects of the 5-HT3-selective antagonists MDL 72222, ondansetron and ICS 205-930 on female sexual behaviour; male rats were studied using ondansetron and granisetron. These compounds influenced neither male nor female copulatory behaviours, suggesting that 5-HT3 receptors contribute little to the modulation of sexual activity. 5-HT3 receptor antagonists block certain opioid-induced behaviours and opioids selectively inhibit sexual behaviours; therefore, the ability of ondansetron and ICS 205-930 to modify morphine-attenuated copulatory activity was also tested. While morphine inhibited copulation, 5-HT3 antagonists failed to reverse the effects.     

Evaluation of nitrogen dioxide scavengers during delivery of inhaled nitric oxide

Tissue hypoxia is an important cause for the development of multisystem organ failure in the critically ill. Achieving adequate haemodynamic support of oxygen demand is the mainstay of treatment in these patients. Controversies regarding therapeutic end-points do exist but in general maintaining oxygen delivery by ensuring adequate cardiac output, oxygen saturation and haemoglobin is important in the critically ill.     

Ultrafiltration after cardiopulmonary bypass in children: effects on hemodynamics, cytokines and complement

OBJECTIVES: The purpose of the study was to evaluate the clinical and hemodynamic effect of intraoperative extracorporeal ultrafiltration (UF) and its potential in reducing the plasma concentration of circulating cytokines and complement activation products following open heart surgery in children. METHODS: Eighteen children with congenital heart disease were prospectively randomized into a control group (n = 9) and a group who underwent UF (n = 9). Serial plasma samples for measurements of circulating cytokines (interleukin 6 (IL-6), tumor necrosis factor alpha (TNF), and its soluble receptor (sTNF receptor)), and complement factors (C3 activation products (C3a and C3bc) and terminal complement complex (TCC)) were obtained before, during and up to 48 h after cardiopulmonary bypass (CPB). A pulmonary artery thermodilution catheter was introduced preoperatively for hemodynamic monitoring. RESULTS: Postoperative hemodynamics were similar in both groups. Plasma levels of IL-6, sTNF receptors, C3a, C3bc and TCC increased significantly perioperatively (P < 0.01) in both groups. TNF was detected transiently in 16 patients perioperatively and in 4 of the 9 ultrafiltrate samples in concentrations similar to the plasma levels. Complement activating products were not detected in the ultrafiltration samples except for small amounts of C3a in two cases. Compared to the control group the plasma levels of C3a, C3bc and TCC were unaffected by the ultrafiltration procedure. The level of IL-6 and sTNF receptors increased significantly after 15 min of UF but there was no significant difference between the two groups postoperatively. CONCLUSIONS: In this study no clinical or hemodynamic effect was registered after UF. TNF and C3a were occasionally detected in the ultrafiltrate but we were unable to demonstrate reduction of these or any of the other markers tested in the group subjected to ultrafiltration.     

Revision with gentamicin-impregnated cement for deep infections in total hip arthroplasties

Seventy-seven total hip arthroplasties complicated by deep infection were treated by reoperation and fixation of a new prosthesis with gentamicin-containing cement. The infection was proved in each case by positive bacterial cultures. Systemic antibiotic treatment was continued for six months postoperatively. Sixty hips were considered healed; the patients had no pain and had normal sedimentation rates and roentgenograms. Nine still had pain or an abnormal sedimentation rate and were classified as doubtful with regard to eradication of the infection. Eight were still infected. The patients were followed for six months to three and one-half years after reoperation.     

The use of salbutamol in obstetrics

Sympathomimetic amines have been used with the aim of abolishing uterine contractions. On the basis of results from an in vivo technique for testing the specificity and affinity of the beta2-receptor stimulating agents, salbutamol was used for a clinical trial. Five case histories were selected in order to illustrate the possibility of utilizing salbutamol in emergency cases with the aim of achieving uterine relaxation during the period of time between the admission of the patient and the commencement of delivery by, for example, caesarean section.