[Parastomal hernia repair and prevention with PHSL type mesh after abdomino-perineal rectum extirpation]. / Reparation und Prävention parastomaler Hernien mit PHSL-Netz nach abdomino-perinealer Rektumexstirpation.

The parastomal hernia is a continuing challenge, because of the disappointing results of the different procedures available to repair it. The mesh implantation seems to be the best, but not optimal method with 8-22 % recurrence rate and about 15-20% other complications. The PHSL (Polypropylene hernia system large; Ethicon inc. Johnson and Johnson, USA) device proved to be an acceptable solution in correction the medium and large parastomal hernia with low recurrence and complication rate. The device enforces the abdominal wall with double mesh layer connected with a tube. The sigmoid colostomy is lifted trough the tube to the abdominal surface. The device was implanted with preventive intent in 14 cases, without any parastomal hernia formation in the first postoperative year. The preventive PHSL mesh implantation at the Miles operation seems to be an useful method for prevention of parastomal hernias.

[Minimal invasive lumbar sympathectomy]. / Minimálisan invazív lumbális sympathectomia.

Forty-four lumbar sympathectomies have been made on 42 patients by ROMICRO-set at the authors' department. This method--made by a specially developed lighting retractor system--ensures the same exposure as the traditional approach, but the visibility of the operative field is much better. The costs of the material character are low. Technique of the operation is discussed. Authors have got good experiences: there were no complications, postoperative pain is minimal, the time of the hospitalization is shortened. A special advantage of this new approach is that it can be even made on patients-belonging to ASA IV., and they can be operated on in epidural anesthesia. The authors recommend this new method only for those surgeons who are experienced in the technique of traditional lumbar sympathectomies.

Miniaturized carbon monoxide sonde for atmospheric measurements.

The design and test results of a simple carbon monoxide detector based on the reducing gas detector principle are presented. This instrument has several features which distinguish it from similar carbon monoxide analyzers, all of which contribute to its usefulness on small airborne platforms such as kites, balloons, and light aircraft. Compact size, battery operation, low cost, and light weight are among the most important improvements made over to earlier systems. The instrument fits a package 10 x 20 x 25 cm, has a mass of 2.0 kg, and consumes an average of 20 W of power. This instrument will, therefore, offer a means of incorporating carbon monoxide measurements in recoverable or disposable balloon sondes. The instrument makes an independent measurement of carbon monoxide every 8 s, with a sensitivity of 3 ppbv carbon monoxide (limit of detection for S/N = 3) and a precision of 4%.

Fast registration and reconstruction of aliased low-resolution frames by use of a modified maximum-likelihood approach.

During the process of microscanning a controlled vibrating mirror typically is used to produce subpixel shifts in a sequence of forward-looking infrared (FLIR) images. If the FLIR is mounted on a moving platform, such as an aircraft, uncontrolled random vibrations associated with the platform can be used to generate the shifts. Iterative techniques such as the expectation-maximization (EM) approach by means of the maximum-likelihood algorithm can be used to generate high-resolution images from multiple randomly shifted aliased frames. In the maximum-likelihood approach the data are considered to be Poisson random variables and an EM algorithm is developed that iteratively estimates an unaliased image that is compensated for known imager-system blur while it simultaneously estimates the translational shifts. Although this algorithm yields high-resolution images from a sequence of randomly shifted frames, it requires significant computation time and cannot be implemented for real-time applications that use the currently available high-performance processors. The new image shifts are iteratively calculated by evaluation of a cost function that compares the shifted and interlaced data frames with the corresponding values in the algorithm's latest estimate of the high-resolution image. We present a registration algorithm that estimates the shifts in one step. The shift parameters provided by the new algorithm are accurate enough to eliminate the need for iterative recalculation of translational shifts. Using this shift information, we apply a simplified version of the EM algorithm to estimate a high-resolution image from a given sequence of video frames. The proposed modified EM algorithm has been found to reduce significantly the computational burden when compared with the original EM algorithm, thus making it more attractive for practical implementation. Both simulation and experimental results are presented to verify the effectiveness of the proposed technique.

The current surgical treatment of primary malignant melanoma of the skin.

In our Department, between 1991 and 1996, 132 patients, there of 87 male-45 female, average age of 48.2 years underwent surgery because of stage 1 (T2) to stage 3 melanoma that was located on the skin. None of patients suffered from early or in situ melanoma. Our retrospective study was based on those 94 patients who had been followed up by Department or dermatology-oncology in our medical centre. Surgery is still the primary treatment for cutaneous malignant melanoma. Thin melanomas (up to 2 mm in thickness) can be excised with 2 cm margins. Whether this is also true for thicker melanomas is not known and the only way to obtain more knowledge is to participate in prospective randomised studies. Elective lymph node dissection is associated with significant morbidity which includes lymphedema, wound complications and paresthesias of the extremity. For this reason we use an alternative operative approach uses selective lymphadenectomy with identification of the sentinel node.

Miniaturized ultraviolet ozonesonde for atmospheric measurements.

The design and test results of a simple single-beam ultraviolet photometer for ozone measurements are presented. The instrument has several features that distinguish it from former UV absorption instruments, all of which contribute to a smaller size and much lower power consumption while retaining the advantages of the UV measurement technique. A novel airflow system and advanced electronics are among the most important changes from earlier reported systems. The instrument fits into a package 10 cm in diameter by 60 cm long and weighs under 1.5 kg. Hence, it is well-suited for lightweight airborne applications using kites and balloons, as well as other portable measurement needs. Independent measurements of ozone are made every 4 s, with a sensitivity of 0.3 ppbv ozone (limit of detection for S/N = 3) and a precision of ±2%.

Effect of heavy metals on the growth of tissue cultures (II).

The effect of toxic concentrations of three heavy metal compounds on the growth of the secondary callus tissue of Nicotiana tabacum L. and Ruta graveolens L. was studied. The metal compounds examined were ZnSO4, NiSO4, CuSO4. The metal compounds used were placed in Murashige, Skoog (1962) and White (1943) culture medium at 10(-6) and 10(-4) M concentration, respectively, before autoclaving. The culture media containing macro- and microelements and vitamins were completed with carbon source and regulators (IAA, GA, kinetin for Nicotiana and IAA, 2, 4-D for Ruta). The cultures were kept for 4 weeks at 25 (+2) degrees C under 16/8 n light/dark conditions. The value of pH was 5.6 before the autoclave treatment. The increase in fresh weight of the secondary callus tissue was inhibited by the metal compounds applied with both plant species (to 75-87% by zinc, 7-97% by nickel, 5-98% by copper with tobacco; to 47-69% by zinc, 5-88% by nickel, 57-90% by copper with rue). The cell number and dry weight per g of callus tissue partly increased, partly decreased compared to the control in response to the heavy metal treatment. The growth values obtained with various concentrations of the heavy metals were different in the two plant species due to differences in metabolism and organization potential between them.

Tissue culture experiments on the vegetative micropropagation of oak.

Excised parts of juvenile green stem, seedlings growing out from unripe acorns and epicotyl segments of seedlings proved to be the best inocula for vegetative micropropagation under the given conditions. By means of interactions between mineral nutrients and supplementary regulators, callus, shoots (shoot sprouting) and regeneration of plantlets were induced from such explants. In the morphology of regeneration, the type of oak inocula rather than the basal medium played a primary role in the experiments described, the latter being just an influencing factor. No regeneration could be induced from resting buds of shoot, meristem tips of axillary buds, anthers or pollen, under the experimental conditions applied. Results obtained, in a further developed form, seem to be suitable for vegetative micropropagation of oaks.