Total mesorectal excision - 40 years of standard of rectal cancer surgery.

Total mesorectal excision (TME) was first described 40 years ago by Richard Heald. The purpose of this article is to point out importance of this surgical procedure. Starting from first attempts to surgically cure rectal carcinoma in the nineteenth century through Miles' operation at the beginning of the twentieth century results were not satisfactory due to high number of local recurrences after resections for rectal cancer. Progress in surgical technique and knowledge of anatomy and embryology of the rectum led to development of TME. Principle of TME is surprisingly simple: removal of the rectum with complete embryonic space containing lymph nodes which are site of primary dissemination of the disease. Main advantages and drawbacks of TME as well as focus on newer procedures developed from the concept of TME are presented in the form of a review.

[Aortocoronary bypass without extracorporeal circulation]. / Aortokoronární bypass bez pouzití mimotelního obehu.

Extracorporeal circulation is nowadays part of the standard technique of aortocoronary reconstruction. The authors summarize in their paper their experience with operations in 45 patients where an aortocoronary bypass was made on the beating heart without the use of extracorporeal circulation. None of the patients died. The incidence of postoperative complications was low. Rapid rehabilitation of the patients and a shorter period of hospitalization makes this method an alternative standard technique of aortocoronary reconstruction.

Comparison of PCR and microscopic methods for detecting Trypanosoma cruzi.

The diagnosis of acute infection with Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease, is generally made by detecting parasites by microscopic examination of fresh blood. Although highly specific, this approach often lacks sensitivity. Several years ago, PCR assays for the detection of T. cruzi were described, but the sensitivities and specificities of these tests have not yet been defined precisely. In the present study, we first compared the sensitivities of PCR methods that differ in sample processing as well as in the target sequences that are amplified. Then, we challenged eight mice with T. cruzi, and on 31 days over a 380-day period, we compared the ability of the PCR method with the highest sensitivity to detect parasites in blood with that of microscopic examination. During the acute phase of the infections, parasites were detected on average 3.9 days earlier by the PCR method than by microscopy. Furthermore, the infected mice were consistently positive by the PCR method during the chronic phase, while parasites were intermittently detected by microscopic examination during that period. Overall, among the 248 comparisons, in 84 the PCR method was positive and no parasites were seen by microscopic examination, whereas the reverse was true in only 1 case, a difference that is highly significant. These findings suggest that this approach should be in patients suspected of having acute Chagas' disease. Moreover, the higher sensitivity of the PCR method observed in both the acute and chronic phases of the T. cruzi infections in the mice that we studied indicates that this approach should be useful in evaluating experimental drugs in T. cruzi-infected laboratory animals.

Attempts to influence movement disorders in hemiparetics.

Step duration, measured in hemiparetic patients walking on a circular path, showed that step duration of the affected foot is usually longer. Functional electrical stimulation of the peroneal nerve in the swing phase of the step (eliminating foot drop) shortened step duration in the majority of cases. Hypnosis induced by the verbal fixation technique was used in hemiparetic patients (a) to ascertain whether the patient's mobility would increase during hypnosis and to determine (in positive cases) whether this approach might be used to predicting the effect of rehabilitation performed by classical methods; (b) to use hypnosis as a method of auxiliary treatment. The general finding was that the extent of movements of the hemiparetic upper extremity considerably improved during and immediately after hypnosis. This effect could be observed both at the level of severe impairment (at the beginning of treatment) and during the later stages when mobility greatly improved due to rehabilitation and recovery.

Slow synaptic excitation in sympathetic ganglion cells: evidence for synaptic inactivation of potassium conductance.

The slow excitatory postsynaptic potential (EPSP) was investigated in frog sympathetic ganglion cells. In contrast to the increased conductance associated with other known EPSP's, during the slow EPSP resting membrane conductance was decreased. Electrical depolarization of the membrane potentiated the slow EPSP, whereas progressive hyperpolarization decreased its size and then reversed it to a hyperpolarizing potential (the opposite of the effect of membrane polarization on other EPSP's). The reversal potential of the slow EPSP was close to the potassium equilibrium potential. We propose that the slow EPSP, in contrast to classical EPSP's, is generated by an inactivation of resting potassium conductance.