Triceratium moreirae sp. nov. and Triceratium dubium (Triceratiaceae - Bacillariophyta) from estuarine environments of Southern Brazil, with comments on the genus Triceratium C. G. Ehrenberg.

A new species of Triceratiaceae is described for estuarine environments of Southern Brazil. The valve of Triceratium moreirae sp. nov. is triangular with elevations bearing ocellus and a rimoportula in their basis. The valvar surface has robust pseudoloculi, circular to polygonal, each one confining a group of areolae arranged in a typical pattern. A central larger areola is surrounded by 5-8 smaller areolae, and they are poroidal with domed cribra. A septum emerges from the valvocopula, having the base reinforced by ribs and the margins folded to the innerside of the valve. The new species is compared to the closely related diatom Triceratium dubium, which has the same pattern of areolar disposition, formation of septum and pseudoloculi. The main differences in relation to T. moreirae are: rimoportulae intercalated to ocelli and with a characteristic morphology (spinules on the edge of the external aperture), and more elongated elevations with a constriction. Some criteria used for the classification of categories into the Triceratiaceae are also discussed, and we propose that the type of areola (poroidal with cribra) be included in the circumscription of Triceratium.

Triceratium moreirae sp. nov. and Triceratium dubium (Triceratiaceae - Bacillariophyta) from estuarine environments of Southern Brazil, with comments on the genus Triceratium C. G. Ehrenberg

A new species of Triceratiaceae is described for estuarine environments of Southern Brazil. The valve of Triceratium moreirae sp. nov. is triangular with elevations bearing ocellus and a rimoportula in their basis. The valvar surface has robust pseudoloculi, circular to polygonal, each one confining a group of areolae arranged in a typical pattern. A central larger areola is surrounded by 5-8 smaller areolae, and they are poroidal with domed cribra. A septum emerges from the valvocopula, having the base reinforced by ribs and the margins folded to the innerside of the valve. The new species is compared to the closely related diatom Triceratium dubium, which has the same pattern of areolar disposition, formation of septum and pseudoloculi. The main diferences in relation to T. moreirae are: rimoportulae intercalated to ocelli and with a characteristic morphology (spinules on the edge of the external aperture), and more elongated elevations with a constriction. Some criteria used for the classification of categories into the Triceratiaceae are also discussed, and we propose that the type of areola (poroidal with cribra) be included in the circumscription of Triceratium

Morphological and immunocytochemical characterization of electrophysiologically investigated neurons in the PVN of the rat.

This study was carried out to characterize angiotensin II (ANG II) sensitive neurons in the hypothalamic paraventricular nucleus (PVN) of the rat. An approach was chosen in which a combination of an electrophysiological, a morphological, and an immunocytochemical method was focused on one single neuron. The cell's reaction to an application of ANG II and its specific antagonist Losartan (Dup753) was investigated using the technique of intracellular recording inside 450-microm-thick brain slices. A final injection of a fluorescent dye labelled the neurons. Optical sections were taken through the marked cells by a confocal laser-scanning microscope and made into a three-dimensional cell model on a computer. One-micrometer thin sections were cut from the thick slice at the level of the electrophysiologically characterized and marked cell body for immunocytochemical tests with different antibodies. Our results show an example of such a neuron inside the PVN excited by ANG II. It was possible to block this excitation with the specific ANG II receptor subtype 1 (AT1) antagonist Losartan. The result indicated that the ANG II reaction was mediated by the AT1 receptor subtype. Immunocytochemical studies show that this ANG II-sensitive neuron contains ANG II but no vasopressin. The combination of the results enables us to gain improved information on interactions of peptidergic systems.

Hypothalamic accessory nuclei and their relation to the angiotensinergic and vasopressinergic systems.

The existence and colocalization of angiotensin II- and vasopressin-like immunoreactivity in individual magnocellular cell groups of the hypothalamus has been demonstrated by using immunocytochemical methods. These neurosecretory magnocellular groups consist of the paraventricular nucleus and the supraoptic nucleus, as well as different accessory cell groups. The fibers from the neurons of the accessory nuclei project directly to adjacent blood vessels and do not comigrate with the hypothalamo-neurohypophysial fiber pathway. On the basis of these findings it can be concluded that in the hypothalamus two different angiotensinergic and vasopressinergic neurosecretory systems exist: (1) an intrinsic hypothalamic and (2) a hypothalamo-neurohypophysial system. The distribution of the accessory cell groups in the hypothalamus is shown in a 3D reconstruction which includes the connection of these magnocellular nuclei with the vascular system in this area.

The neuronal role of angiotensin II in thirst, sodium appetite, cognition and memory.

Within the past two decades, a great deal has been learnt about the renin-angiotensin system in the brain. The renin-angiotensin system is one of the best-studied enzyme-neuropeptide systems in the brain. The diversity of localization of this peptide throughout the brain has implied a variety of potential functions. Besides its classical role in the regulation of blood pressure and body-fluid homeostasis, it has more subtle functions involving complex mechanisms such as learning and memory. The profound effects on behaviour produced by angiotensin are of broad interest to neuroscientists. The mechanisms of action differ depending on whether angiotensin is locally synthesized and whether regulation is governed by neural or metabolic inputs impinging on the neurones. Its central action is mediated through peptidergic receptors present on neurones. The description of the receptor subtypes AT1 and AT2 for angiotensin II and the development of non-peptidic specific angiotensin receptor subtype antagonists have opened a new area in this field of research. The AT1 site, which preferentially binds to angiotensin II and angiotensin III, appears to mediate the classical angiotensin functions concerned with maintenance of blood pressure and body-fluid control. In addition, most of the behavioural effects described so far are linked with AT1, although so-called psychotropic effects are presumed to be mediated by receptor systems other than the known specific angiotensin receptors. In fact, evidence for the existence of such receptors with high-affinity binding has been reported. The central action of angiotensin II mediated by AT2 is as yet unclear. Most reports concerning this receptor subtype suggest a role in differentiation and development, since the number of binding sites is higher in fetal and young rats than in adults. Furthermore, the neuronal effect of angiotensin II in the inferior olivary nucleus which is blocked specifically by AT2 antagonists suggests an involvement in motor control. Over the next few years we should find answers to many of the questions currently unanswered about angiotensin function and, given the rapid progress in research on this neuropeptide, it may serve as a model for the action of peptides on neuronal function in general.

Effect of gastro-esophageal decongestion on variceal pressure in patients with schistosomal hepatic fibrosis.

This study includes 60 patients having schistosomal hepatic fibrosis and esophageal varices. Splenectomy alone was done for 14 patients having no history of haematemesis and gastroesophageal decongestion with splenectomy was done for the remaining 46 patients with history of haematemesis. Endoscopic variceal pressure measurements were done to all of them peroperatively and 21 days postoperatively. 17 patients, 7 after splenectomy and 10 after gastro-esophageal decongestion, were followed for 18 months post operatively. 21 days postsplenectomy, the variceal pressure dropped insignificantly from 38.09 to 33.27 cm H2O. During the following 18 months, three patients out of seven showed significant increase in variceal pressure. After decongestion with splenectomy, the mean variceal pressure dropped significantly from 42.03 to 29.17 cm H2O. For the 10 patients followed for 18 months, eight of them retained their variceal pressure as low as early postoperative figures. Thus gastro-esophageal decongestion with splenectomy is effective in reducing variceal pressure and in so doing it is better than splenectomy alone.

[Liver transplantation. Initial Lausanne experiences]. / Transplantation hépatique. Premières expériences lausannoises.

This paper presents the results of the first 7 orthotopic liver transplants performed in Lausanne between December 1988 and September 1990. 6 patients are surviving; their rehabilitation is excellent.

Portal vein thrombosis of the adolescent: indications for autologous internal jugular vein interposition meso-caval shunt.

Endoscopic sclerotherapy is now the treatment of first choice for oesophageal varices. However, in spite of its efficiency and safety, recurrent bleeding remains possible and oesophageal sclerosis does not cure other potentially incapacitating symptoms related to portal hypertension. This report describes four adolescents with prehepatic hypertension for whom sclerotherapy was inadequate. They were treated successfully by an autologous internal jugular vein interposition mesocaval shunt. This operation is safe, decompresses the whole splanchnic territory and obviates the need for long term endoscopic surveillance.

[Y-loop gastrojejunostomy in postoperative gastritis caused by reflux]. / Gastro-jéjunostomie sur anse en Y pour gastrite post-opératoire par reflux.

This prospective study involving 24 patients operated for postoperative reflux gastritis spanned over the period between 1974 and 1987. Diagnosis by exclusion was based on clinical, endoscopic and histological findings collected a few months to 16 years following surgery, the outcome of which was either alteration or destruction of the antropyloric sphincteral mechanism. All patients had Y-loop gastrojejunostomy performed according to Roux's procedure (at 50 cm). The clinical results as assessed on the basis of Visick's score and by gastroscopy were good. Anatomopathological examination of pre- and postoperative bioptic specimens blind-collected by a single operator indicated that foveolar hyperplasia is a good indicator of enterogastric reflux.

[Conservative treatment of splenic injuries in the adult]. / Traitement conservateur des traumatismes spléniques chez l'adulte.

Because of the risk of overwhelming post-splenectomy infection, the current trend favors conservative treatment for splenic trauma. Out of a total of 70 cases of splenic trauma in adults seen over the last 5 1/2 years, 19 spleens were preserved, 13 with, 6 without operations. Ten operated spleens were examined by Duplex-sonography, on average 38 months after surgery. The results show that in all cases, the spleen was morphologically and hemodynamically restored to normal.

[Quantitative measure of the output of the deep abdominal vessels with a new device Duplex. Preliminary results]. / Mesure quantitative du débit de vaisseaux abdominaux profonds par un nouvel appareil Duplex. Résultats préliminaires.

Deep abdominal vessels blood flow can be measured noninvasively with the relation Q = V x A, where Q = flow, V = blood velocity and A = area of the considered vessel. In most Duplex devices, V is only calculated as a mean by the Doppler effect and A estimated by an echograph. Our newly developed multi-gated pulsed Doppler provides the velocity profile across the vessel, so minimizing errors in flow determination. On fifty healthy volunteers, we found flow of 717 +/- 238 ml/min for the portal vein, 1594 +/- 293 ml/min for the upper abdominal aorta and 794 +/- 168 ml/min for the lower aorta. These results are obtained through many technical and practical problems, but are feasible, even if still subject to errors. Further investigation will determine if the technique is also suitable for patients. Better assessment of deep abdominal vessels hemodynamics may be expected.

[Cure of recurrent ascites in alcoholic hepatitis following transient placement of a LeVeen shunt]. / Guérison de l'ascite réfractaire dans l'hépatite alcoolique, après mise en place transitoire d'un shunt de LeVeen.

Three cases of severe alcoholic hepatitis associated with refractory ascites are reported. A LeVeen shunt was inserted which was effective and well tolerated. However, the shunt was removed in all 3 patients 8 months, 12 months and 9 years after insertion because of spontaneous migration (n = 2) or superior vena cava thrombosis (n = 1). At time of shunt removal all 3 patients had micronodular cirrhosis, but none had recurrent ascites during the 1-3 years of observation and despite the absence of diuretics. The eventual transient aspect of refractory ascites associated with alcoholic hepatitis is discussed, together with the potential beneficial and temporary role of LeVeen shunts in this condition.

Portal pressure measurements before and after Hassab's decongestion operation. A preliminary report.

This preliminary study included five patients with a history of haematemesis resulting from rupture of oesophageal varices complicating schistosomal hepatic fibrosis. Simultaneous measurements were taken of the endoscopic variceal pressure (EVP) and the free portal pressure (FPP) obtained by the cannulation of a mesenteric vein radical. These measurements were taken after laparotomy, after removing the spleen and after devascularization of the lower oesophagus and upper two thirds of the stomach. At the beginning the EVP was found to be identical with the FPP. Following splenectomy, the EVP dropped from a mean of 41.9 cm H2O to a mean of 25.8 cm H2O, whereas the FPP dropped from 40.7 cm H2O to 27.8 cm H2O. After decongestion, the EVP had a mean of 21.3 cm H2O and the FPP had a mean of 32 cm H2O. Two weeks after the operation the EVP remained unchanged at the end of the operation in two cases and increased by 5 cm H2O in one case. Accordingly it was concluded that Hassab's operation results in an immediate diminution of the EVP and FPP. However, the long-term results of this operation required further studies.

[Endoscopic sclerosing for hemorrhage due to ruptured esophageal varices. Results of a prospective study of 50 cases]. / Sclérose endoscopique pour hémorragie sur rupture de varices oesophagiennes. Résultats d'une étude prospective sur 50 cas.

A prospective evaluation of sclerotherapy for bleeding esophageal varices has been conducted in 50 unselected consecutive patients. According to Child's classification, 36% were class A, 34% class B and 30% class C. Sclerotherapy was performed on an emergency basis in 22 patients and was delayed a few hours for the others. The aim of the technique was to obliterate the varices by intra- and paravariceal injections of polidocanol 1%. Injections were performed weekly for the first 3 weeks of treatment, then 3- or 6-monthly. Four patients had a severe recurrent hemorrhage during the first month. The mortality during that period was 12%. Follow-up was possible in 81% of the surviving patients. Four stenoses were treated by dilatation. Four patients had a late-recurring hemorrhage which was easily controlled in 3. Four patients died later, 3 of liver insufficiency and one of hemorrhage.

Quantitative pulsed Doppler measurement of common femoral artery blood flow variables during postocclusive reactive hyperemia.

Quantitative blood flow measurements were performed on 37 normal lower limbs with a 128-channel digital pulsed Doppler (MDPD) system. The evolution of mean flow (QM), peak systolic flow (QS), diastolic flow (QD), and prograde stroke volume (PSV) was observed at rest, during postocclusive reactive hyperemia (PORH), and at 1-, 2-, and 3-min intervals. The QM at rest was 2.9 +/- 1.1 ml/s; PORH induced a four- to fivefold increase in QM and PSV secondary to a slight increase in QS and the disappearance of the reverse protodiastolic component of resting flow. Reverse flow was restored after 1 min. Both QS and QD returned to resting values after 2 min, whereas QM remained significantly higher after 3 min. To provide a better description of the hyperemic response, we also studied the evolution of the pulsatility index as as applied the flow curve (PIQ). Similarly, the systolic amplitude index (SAI) is presented. Our study demonstrates that pulsed Doppler techniques can be used for noninvasive quantitative assessment of blood flow at rest and during PORH. The values obtained on normal subjects provide base-line data for further investigation of pathological conditions.