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The effects of field dodder on physiological and anatomical processes in untreated sugar beet plants and the effects of propyzamide on field dodder were examined under controlled conditions. The experiment included the following variants: N-noninfested sugar beet plants (control); I - infested sugar beet plants (untreated), and infested plants treated with propyzamide (1500 g a.i. ha-1 (T1) and 2000 g a.i. ha-1(T2)). The following parameters were checked: physiological-pigment contents (chlorophyll a, chlorophyll b, total carotenoids); anatomical -leaf parameters: thickness of epidermis, parenchyma and spongy tissue, mesophyll and underside leaf epidermis, and diameter of bundle sheath cells; petiole parameters: diameter of tracheid, petiole hydraulic conductance, xylem surface, phloem cell diameter and phloem area in sugar beet plants. A conventional paraffin wax method was used to prepare the samples for microscopy. Pigment contents were measured spectrophotometrically after methanol extraction. All parameters were measured: prior to herbicide application (0 assessment), then 7, 14, 21, 28 and 35 days after application (DAA). Field dodder was found to affect the pigment contents in untreated sugar beet plants, causing significant reductions. Conversely, reduction in the treated plants decreased 27% to 4% for chlorophyll a, from 21% to 5% for chlorophyll b, and from 28% to 5% for carotenoids (T1). Also, in treatment T2, reduction decreased in infested and treated plants from 19% to 2% for chlorophyll a, from 21% to 2% for chlorophyll b, from 23% to 3% for carotenoids and stimulation of 1% and 2% was observed 28 and 35 DAA, respectively. Plants infested (untreated) by field dodder had lower values of most anatomical parameters, compared to noninfested plants. The measured anatomical parameters of sugar beet leaves and petiole had significantly higher values in noninfested plants and plants treated with propyzamide than in untreated plants. Also, the results showed that propyzamide is an adequate herbicide for control of field dodder at the stage of early infestation.

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BACKGROUND: Peripheral nerves are situated in a highly non-homogeneous environment, including muscles, bones, blood vessels, etc. Time-varying magnetic field stimulation of the median and ulnar nerves in the carpal region is studied, with special consideration of the influence of non-homogeneities. METHODS: A detailed three-dimensional finite element model (FEM) of the anatomy of the wrist region was built to assess the induced currents distribution by external magnetic stimulation. The electromagnetic field distribution in the non-homogeneous domain was defined as an internal Dirichlet problem using the finite element method. The boundary conditions were obtained by analysis of the vector potential field excited by external current-driven coils. RESULTS: The results include evaluation and graphical representation of the induced current field distribution at various stimulation coil positions. Comparative study for the real non-homogeneous structure with anisotropic conductivities of the tissues and a mock homogeneous media is also presented. The possibility of achieving selective stimulation of either of the two nerves is assessed. CONCLUSION: The model developed could be useful in theoretical prediction of the current distribution in the nerves during diagnostic stimulation and therapeutic procedures involving electromagnetic excitation. The errors in applying homogeneous domain modeling rather than real non-homogeneous biological structures are demonstrated. The practical implications of the applied approach are valid for any arbitrary weakly conductive medium.

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BACKGROUND: Electromagnetic stimulation of the nervous system has the advantage of reduced discomfort in activating nerves. For brain structures stimulation, it has become a clinically accepted modality. Coil designs usually consider factors such as optimization of induced power, focussing, field shape etc. In this study we are attempting to find the effect of the coil contour shape on the electrical field distribution for magnetic stimulation. METHOD AND RESULTS: We use the maximum of the induced electric field stimulation in the region of interest as the optimization criterion. This choice required the application of the calculus of variation, with the contour perimeter taken as a pre-set condition. Four types of coils are studied and compared: circular, square, triangular and an 'optimally' shaped contour. The latter yields higher values of the induced electrical field in depths up to about 30 mm, but for depths around 100 mm, the circular shape has a slight advantage. The validity of the model results was checked by experimental measurements in a tank with saline solution, where differences of about 12% were found. In view the accuracy limitations of the computational and measurement methods used, such differences are considered acceptable. CONCLUSION: We applied an optimization approach, using the calculus of variation, which allows to obtain a coil contour shape corresponding to a selected criterion. In this case, the optimal contour showed higher intensities for a longer line along the depth-axis. The method allows modifying the induced field structure and focussing the field to a selected zone or line.

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BACKGROUND: Magnetic stimulation has gained relatively wide application in studying nervous system structures. This technology has the advantage of reduced excitation of sensory nerve endings, and hence results in quasi-painless action. It has become clinically accepted modality for brain stimulation. However, theoretical and practical solutions for assessment of induced current distribution need more detailed and accurate consideration. Some possible analyses are proposed for distribution of the current induced from excitation current contours of different shape and disposition. Relatively non-difficult solutions are shown, applicable for two- and three-dimensional analysis. METHODS: The boundary conditions for field analysis by the internal Dirichlet problem are introduced, based on the vector potential field excited by external current coils. The feedback from the induced eddy currents is neglected. Finite element modeling is applied for obtaining the electromagnetic fields distribution in a non-homogeneous domain. RESULTS: The distributions were obtained in a non-homogeneous structure comprised of homogeneous layers. A tendency was found of the induced currents to follow paths in lower resistivity layers, deviating from the expected theoretical course for a homogeneous domain. Current density concentrations occur at the boundary between layers, suggesting the possibility for focusing on, or predicting of, a zone of stimulation. CONCLUSION: The theoretical basis and simplified approach for generation of 3D FEM networks for magnetic stimulation analysis are presented, applicable in non-homogeneous and non-linear media. The inconveniences of introducing external excitation currents are avoided. Thus, the possibilities are improved for analysis of distributions induced by time-varying currents from contours of various geometry and position with respect to the medium.

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BACKGROUND: Transthoracic defibrillation is the most common life-saving technique for the restoration of the heart rhythm of cardiac arrest victims. The procedure requires adequate application of large electrodes on the patient chest, to ensure low-resistance electrical contact. The current density distribution under the electrodes is non-uniform, leading to muscle contraction and pain, or risks of burning. The recent introduction of automatic external defibrillators and even wearable defibrillators, presents new demanding requirements for the structure of electrodes. METHOD AND RESULTS: Using the pseudo-elliptic differential equation of Laplace type with appropriate boundary conditions and applying finite element method modeling, electrodes of various shapes and structure were studied. The non-uniformity of the current density distribution was shown to be moderately improved by adding a low resistivity layer between the metal and tissue and by a ring around the electrode perimeter. The inclusion of openings in long-term wearable electrodes additionally disturbs the current density profile. However, a number of small-size perforations may result in acceptable current density distribution. CONCLUSION: The current density distribution non-uniformity of circular electrodes is about 30% less than that of square-shaped electrodes. The use of an interface layer of intermediate resistivity, comparable to that of the underlying tissues, and a high-resistivity perimeter ring, can further improve the distribution. The inclusion of skin aeration openings disturbs the current paths, but an appropriate selection of number and size provides a reasonable compromise.

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The authors report a case of acute peritonitis due to intraperitoneal perforation of an infected urachal cyst. A review of the literature found only 15 similar cases. The presence of a lower midline mass, an umbilical discharge together with ultrasound examination should suggest the possibility of urachal pathology, especially and urachal cyst, with subsequent surgical treatment.

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This retrospective study was undertaken to evaluate the incidence of an abnormal pancreaticobiliary ductal union (long common duct) in biliary tract carcinoma. Of 86 patients presenting with such a cancer, 67 had a pre- or intra-operative radiologic examination. An abnormal pancreaticobiliary ductal union was found in only one 60 year old woman having stones associated with invasive gallbladder carcinoma. Operative cholangiogram revealed an early and marked Wirsung opacification with a 1.5 cm long common duct. This low incidence in our study contrasts deeply with Japanese data and raises several questions about the correct evaluation of pancreaticobiliary ductal union, the true consequences of such an anomaly and possible interracial variations in incidence.

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The treatment of post-operative eventration with major loss of parietal substance often justifies the use of prosthetic material. 62 post-operative patients from a series of 345 benefited from such a procedure. In the majority of cases they were patients who had undergone multiple surgery and also one or many attempts to cure the eventration (55%). The eventrations were of large volume and complex and one or more operative risk factors were present (81%). A Mersilene grid, implanted retromuscularly in all but one case, was the prosthetic material used in 96% of cases. Operative mortality in this series was zero, but unfortunately post-operative hematomas occurred in 27% of cases and one half of these became infected. Recurrent eventration (11%) was seen in all but one case where post-operative infection occurred. In five out of six cases under these circumstances this became apparent during the first post-operative year. The authors stress the fundamental importance of peri-operative care during such interventions; the quality of post-operative results depends, to a large extent, on this care and on the respect of the peroperative technical principles defined by the authors.

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101 patients with splenic trauma were treated during the period 1978 to 1988. They included 76 men and 25 women aged between 16 and 85 years, with a mean age of 38 years 6 months. Exclusively splenic lesions were present in 33 cases (32.67%) and bony or visceral lesions were also present in 68 cases (67.33%). 61 cases (60.39%) suffered from multiple trauma. 97 patients underwent laparotomy, 86 (85.1%) subsequently underwent total splenectomy and 11 (10.8%) conservative surgical treatment (10 partial splenectomies and 1 splenorrhaphy). Four patients did not undergo surgery and were kept under surveillance in a surgical ward for 3 weeks. The majority of partial splenectomies were carried out after 1985 though the first was performed in 1981. There was no operative mortality and post-operative mortality was 9.9% (10 deaths). The overall mean duration of hospitalisation was 20.2 days: 15.6 days for patients who underwent partial splenectomy, 19.6 days for patients who underwent total splenectomy and 21 days for cases involving simple surveillance. Operative complications occurred in 28 patients who underwent laparotomy. Complications did not occur in the 4 patients who received simple surveillance. The most frequent complications were sepsis, pneumonia, thrombo-embolic complications and four patients required reoperation for hemoperitoneum. Conservative surgical treatment is increasingly being used in splenic trauma. The criteria for avoidance of surgical intervention remain difficult to define at the present time.

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Delayed perineal healing after rectal amputation is sometimes difficult to resolve. Details are given of a method of transplantation into the residual perineal cavity of one or both gracilis muscles to obtain rapid healing by granulation tissue. Preparatives for the operative are discussed together with the different stages required, particularly preparation of the transplant and its transposition to perineal cavity, and postoperative surveillance outlined. Rapid healing by scar tissue can be obtained by this simple procedure which can also be applied for treatment of vesicovaginal, rectovesical or rectovaginal fistula.

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Some publications have pointed out that oxygen free radicals can induce injury of vessel wall and increase platelet aggregation and clotting, which can suppose a dependent relationship with arteriosclerotic process. We therefore studied the hypothesis of a possible abnormal platelet antioxidant enzymatic equipment in arteriopathic patients. A control group of 20 healthy subjects and an other one of 40 non diabetic patients with peripheral arterial disease were investigated, and the following tests were performed: measure of transcutaneous oxygen tension (PTCO2), determination of activity of platelet superoxide dismutase (SOD), glutathione-peroxidase (G-Px) and catalase (CAT). A significant decrease of SOD and G-Px is observed in platelets of arteriopathic patients. This decrease seems to be correlated with the severity of ischemia. The pathological reduction of platelet antioxidant equipment can be one factor enhancing thrombotic complications in chronic arterial disease.

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The sedimentation profiles of IgA and Secretory Component (SC) and the concentrations of IgA, IgG, IgM, SC and albumin were evaluated after an overnight fast in gall bladder bile of six adult subjects without hepatobiliary disease. The sedimentation profiles differed from those previously obtained in hepatic bile in three ways: gall bladder bile contained a greater percentage of free-SC, a greater percentage of polymeric-IgA (p-IgA), and a major peak of 14 to 19 S p-IgA associated to SC. In contrast to hepatic bile in which IgG is the predominant Ig, IgA clearly was the predominant Ig in gall-bladder bile, its concentration averaging 92 micrograms/ml. Relative-to-albumin coefficients of excretion of proteins in gall bladder bile averaged 0.99 for IgG, 8.6 for monomeric IgA, 196 for p-IgA and 31 for IgM, indicating that there was a selective excretion of IgA and IgM into gall bladder bile. As compared to hepatic bile, the enrichment of gall bladder bile with IgA and IgM was respectively 6.5 and 11.5 times greater than with IgG. These results suggest that quite a significant amount of p-IgA could have been added to bile during its storage in the gall bladder which should therefore be regarded as the predominant source of bile IgA in humans.

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The aim of this study was to assess the role of mesenteric blood in polymeric IgA (p-IgA) and IgA2-transport from the intestinal mucosa into plasma and the role of the liver in the clearance of these molecular forms of IgA. The concentrations of IgA, p-IgA and IgA2 were measured in mesenteric, splenic, portal, and hepatic veins of 7 control subjects without liver disease and in portal and peripheral veins of 4 patients with alcoholic cirrhosis. In control subjects, the concentration of the different molecular forms of IgA were not significantly different in mesenteric and in splenic vein. No significant decrease of IgA concentrations was observed in hepatic vein, as compared with portal vein. In cirrhotic patients IgA concentrations were significantly higher than in control subjects, but concentrations of IgA, p-IgA and IgA2 were not different in portal and peripheral blood. These results show that mesenteric vein is not a major way for p-IgA and IgA2 from the gut lamina propria to plasma, and suggest that the origin of a significant part of these molecular forms of IgA could be peripheral lymph-nodes more than gut-associated-lymphoid-tissue. The absence of significant clearance of p-IgA by the liver in normal subjects suggests that abnormalities of hepato-biliary transport of p-IgA is not responsible for the increased IgA levels observed in cirrhotic patients.

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Our aim was to determine whether or not postprandial retrograde duodenal pacing would abolish the canine postgastrectomy dumping syndrome. Five dogs underwent truncal vagotomy, distal hemigastrectomy, gastroduodenostomy, and circumferential proximal duodenal myotomy to facilitate pacing. Bipolar stimulating electrodes from an implanted pacing unit were attached to the bowel 35 cm distal to the gastroduodenostomy, and six monopolar recording electrodes were applied at 5-cm intervals proximal to the pacing electrodes. After recovery, gastric emptying was assessed in the fasted conscious dogs using 300-ml gastric instillates of 25% dextrose marked with [14C]polyethylene glycol, while pulse, hematocrit, and defecation were monitored. Each dog underwent five tests with and five tests without retrograde duodenal pacing. Without pacing, the dogs emptied a mean +/- SEM of 237 +/- 14 ml of the instillate by 20 min and developed tachycardia (change in pulse, 45 +/- 4), hemoconcentration (change in hematocrit, 8 +/- 1), and diarrhea in 13 of 25 tests. Retrograde duodenal pacing slowed gastric emptying (157 +/- 20 ml, p less than 0.05) and minimized the adverse cardiovascular sequelae (change in pulse, 25 +/- 5, change in hematocrit, 6 +/- 1; p less than 0.05) and the diarrhea (only 2 of 25 tests, p less than 0.01). We concluded that intestinal pacing ameliorated the postgastrectomy dumping syndrome in dogs. Such an approach may be applicable to humans.

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