Production of radioactive phantoms using a standard inkjet printer and the public domain multi-printing code GENIA.

The public domain code GENIA, based on multi-printing method for producing surface sources with appropriate radioactivity, is described. The conventional technique, running on standard inkjet printer with radio-marked ink filling, is improved by repeating elementary printing commands in the same band. Well outlined sources with adjustable radioactivity can be obtained without refilling. The intrinsic limitation of printable radioactivity, depending on the value available at nozzles at printing time, was overcome. In addition the method permits the accurate calibration of the amount of activity released onto the paper.

Effects of mivacurium on the diaphragm evaluated by cervical magnetic stimulation of the phrenic nerves.

BACKGROUND AND OBJECTIVE: Non-depolarizing neuromuscular blocking agents have differential effects on the diaphragm and skeletal muscles. We employed a new method to study the effects of mivacurium on the diaphragm and compared the results obtained with this method with published data. METHODS: Anaesthesia was induced and maintained with propofol and alfentanil and the trachea was intubated after topical anaesthesia. Contractions of the diaphragm were induced by cervical magnetic stimulation of the phrenic nerves and quantified by measuring airway pressure responses. The neuromuscular effects on skeletal muscles were measured by acceleromyography of the adductor pollicis muscle. Mivacurium (0.15 mg kg(-1)) was injected and neuromuscular responses were recorded until the effects had waned. RESULTS: Eleven male and 10 female patients (ASA I-II; 57 +/- 16 yr; 78 +/- 13 kg; mean +/- standard deviation) participated. Median maximal reduction of twitch response was less (P < 0.05) for the diaphragm (89%) than for the adductor pollicis (100%). Time to 25% recovery was shorter for the diaphragm than for the adductor pollicis (8.8 +/- 2.2 min vs. 22.6 +/- 5.0 min, P < 0.05). The difference between the recovery index of the diaphragm (7.3 min (3.6-18.4)) and the adductor pollicis (8.2 min (4.4-20.9) (median (range)) just missed our chosen level of statistical significance (P = 0.06). The recovery time to train-of-four 0.8 was shorter for the diaphragm (median and 95% confidence interval 25.1 +/- 10.2 min) than for the adductor pollicis (median and 95% confidence interval 37.5 +/- 9.4 min, P < 0.05). CONCLUSIONS: The duration of the clinical effect of mivacurium on the diaphragm is markedly shorter than on the adductor pollicis muscles but there was only a small difference in the recovery index of the two muscles. These effects and the time courses determined with the new method closely resemble the results obtained with different methods in other studies.

Extraesophageal autonomic dysfunction in patients with achalasia.

A disagreement exists as to whether extraintestinal parasympathetic autonomic function is altered in patients with esophageal achalasia. Therefore, we assessed autonomic dysfunction in esophageal achalasia and considered the most relevant parameters of parasympathetic autonomic function in these patients. In a prospective study, heart rate variation and pupillary function were investigated in 15 patients with achalasia of the esophagus and in 15 controls by application of a battery of standardized autonomic function tests. Significant differences between patients and controls were detected for various parameters of heart rate variation and pupillometry. When compared to values obtained from large groups of healthy subjects, none of the controls but 11 patients had at least one abnormal parameter of parasympathetic autonomic function. It is suggested that in esophageal achalasia parasympathetic dysfunction that extends beyond the gastrointestinal tract can be frequently detected. This finding supports the view of a generalized alteration of the autonomic nervous system in achalasia.

Autonomic dysfunction in patients with achalasia of the oesophagus.

It has been suggested that achalasia is associated with extraoesophageal sympathetic and parasympathetic dysfunction. In a prospective study we applied conventional ultrasonography and duplex sonography to investigate basal and postprandial peak systolic velocity (PSV), pulsatility index (PI) and resistance index (RI) of superior mesenteric artery and PSV of portal vein in nine patients with achalasia and 10 healthy controls (study I). In addition, in eight of these patients autonomic nervous function was investigated by pupillary function tests as well as cardiovascular reflex tests and compared with eight age- and sex-matched controls (study II). The results indicated that postprandial increase of PSV in the superior mesenteric artery was significantly lower, and postprandial decrease of PI and RI significantly higher in achalasia compared to healthy controls. In contrast, postprandial increase of PSV in the portal vein was not significantly different between both groups. Autonomic function tests revealed significant lower maximal pupillary contraction and redilatation velocities, significantly lower heart rate variation during orthostasis, deep respiration test and Valsalva manoeuvre in achalasia compared to controls. It is concluded that achalasia is associated with extraoesophageal autonomic nervous dysfunction that involves cardiovascular and pupillary function as well as regulation of mesenteric arterial blood flow.

Autoantibodies to Auerbach's plexus in achalasia.

Achalasia is a motor disorder of the oesopagus characterized by decrease in ganglion cell density in Auerbach's plexus. The cause of the lesion is unknown. This is to repeat on the occurrence of autoimmune phenomena in patients with achalasia, in particular circulating antibodies against Auerbach's plexus and its possible meaning. IgG-antibodies against Auerbach's plexus were determined by standard indirect immunofluorescence. Antibodies to the cytoplasm of Auerbach's plexus were found in 37 of 58 patients with achalasia at variable stages of the disease (I-IV) with a disease duration ranging from 1 to 20 years but only in 4 out of 54 healthy controls (specificity 93%, sensitivity 64%, p < 0.0001), and in none of 12 patients with Hirschsprung's disease as well as 12 patients with cancer of oesophagus and only in one of 11 patients with peptic oesophagitis as well as in one of 13 patients with myasthenia gravis. The present observations suggest that autoimmunity to Auerbach's plexus plays a role in the pathogenesis of achalasia, the mechanism of action is unknown.

Minimal invasive procedures in neurosurgery.

Ever since surgery was introduced for the treatment of neurological diseases, miniaturized approaches have been considered and developed in order to limit trauma of vital and delicate structures of the central nervous system. Thus, the application of stereotactic techniques and endoscopy date back to the beginning of this century. Stereotactic neurosurgery started with the goal of reaching target areas in the brain through a burrhole and then to guide (by the aid of landmarks on the bony skull and its radiographic image) small instruments such as needles and biopsy forceps. Moreover, ventriculograms with contrast material were used as guides to calculate coordinates for a 3-dimensional guiding-system within the brain. Coordinates for the brain's interior structures had to be taken from a theoretical average human brain as shown in a stereotactic brain atlas.

[Normothermal extracorporeal perfusion of the liver]. / Perfuzie extracorporeala normoterma de ficat.

In view of providing hepatic assistance, and for conservation aims in attempts at transplantation conditions have been investigated for achieving extracorporeal normothermal perfusion of the liver isolated from pig and dog. A total of 33 experiments have been performed. The preparations and the devices used allow to apply the method in a patient only after stabilisation of the perfusion, and frees the medical team from a series of technical problems. The duration and the quality of the perfusion are especially influenced by the collecting technique. In the dog the liver should be removed 3--5 hours, and in the pig 7--8 hours before perfusion is started. The functional condition of the liver can be assessed at 45 minutes after the start of the perfusion by evaluating the following criteria: the macroscopic aspect of the liver, the blood flow, the biliary flow, the ascitis fluid, TGP and oxygen consumption. Adequate installations and a permanent involvement of the laboratory team are essential conditions for the application of this method to the treatment of acute severe hepatic failure.