[K (killer) and NK (natural killer) cells: characteristics, functions and biological properties (author's transl)]

Cell-mediated cytotoxicity is considered to be an important defence system of the body in the case of virus diseases, transplant rejection and in the early stages of cancer. Apart from T lymphocytes, two types of effector cells which lyse tissue culture cells by different mechanisms have been investigated intensively over the past decade--K (killer) and NK (natural killer) cells. K cells possess the capacity to lyse antibody-coated target cells. These effector cells have been described to occur mainly in peripheral blood and spleen. They are small lymphocyte-like cells which possess receptors for the Fc part of immunoglobulin G. Other surface markers may be present on these cells, depending on the organ of isolation. Other cytotoxic effector cells with similar morphology and surface markers possess the capacity to lyse tissue culture cells without participation of antibody and without in vitro or in vivo sensitization. These cells are called NK cells and are found in peripheral blood, spleen, tonsils and lymph nodes. Up to now neither type of effector cells has been unequivocably identified as mature B or T cells, granulocytes, monocytes or macrophages. Differences exist between the effector mechanisms of K and NK cells, as shown by different susceptibility to modulation of effector cell function by cortisone and, probably, by interferon. Whether K and NK cells represent functional stages of identical cells and furthermore, whether these cells belong to a third lymphocyte population or represent immature mononuclear cells are questions remaining to be clarified.

[High-dose ifosfamide therapy: systemic use of a mucolytic agent for the reduction of urotoxicity]

Ifosfamid is an alkylating cytostatic agent which appears to differ in its clinical spectrum from the chemically similar cyclophosphamid. So far, however, its pronounced urotoxicity has limited dosage. In spite of prophylactic measures such as forced diuresis and alkalinization of the urine, the treatment has frequently has to be broken off because of macrohematuria and hemorrhagic cystitis. By repeated intravenous administration of sodium-mercapto-ethan-sulfonate (NNI: Mesnum) the urotoxic side effects of ifosfamid can largely be prevented. During 26 cycles of treatment in 18 patients, asymptomatic microhematuria was observed 6 times and macrohematuria only once in a patient with vesico-vaginal fistula. In another case where therapy had had to be discontinued because of hemorrhagic cystitis in spite of conventional prophylaxis, the treatment could be continued without change in the urine sediment under prophylaxis with Mesnum. Mesnum does not affect the antitumoral activity of ifosfamid.

Krypton-81m in the physiologic assessment of coronary arterial stenosis in man

Fifteen patients with frequent anginal chest pain underwent diagnostic cardiac catheterization. After coronary arteriography a specially designed cardiac catheter was seated in the aortic root, permitting the continuous infusion of krypton-81m into the right and left aortic sinuses. A gamma camera, areas of interest and a visual display unit were used to record images and the regional myocardial equilibrium of activity before, during and after a standarized atrial pacing test. The unique physical properties of krypton-81m allowed the continuous imaging and recording of moment to moment changes in regional myocardial perfusion. This investigation revealed that when the coronary arteriogram was normal or revealed lumonal stenosis of less than 50 percent, regional myocardial perfusion was uniform at rest and during stress. Two patients with a previous history of myocardial infarction had defects of regional perfusion at rest and during stress. Krypton scintigraphy demonstrated reversible regional defects in myocardial perfusion during stress in seven patients with greater than 70 percent stenosis of one or more coronary arteries. Alterations in regional myocardial perfusion occurred within 30 seconds of the start of atrial pacing in all the patients and preceded the onset of electrocardiographic signs of ischemia or chest pain.

[Experiences with hyperbaric bupivacaine solutions in spinal analgesia (author's transl)]

Spinalanaesthesia with hyperbaric bupivacaine (0.4%, 1.0%, 0.5%) was used in 713 patients having general surgical and urological operations. On average 19.30 +/- 1.55 mg bupivacaine was given and a spread of anaesthesia up to Th 7.21 +/- 1.55 achieved. Detailed evaluation of the 3rd group (0.5%) showed a latency period of 2.21 +/- 0.82 min and mean effective time of 4.33 +/- 0.75 h. The motor blockade was in 87% complete. The problem of the 0.5% solution with a specific gravity of 1.037 g/ml, which is in our opinion too high, was pointed out and a recommendation for a specific gravity of about 1.020 g/ml was given. Assuming proper positioning, spinal anesthesia with hyperbaric bupivacaine is a safe and simple anaesthetic method.

[Clinical trial of bupivacaine-CO2 (author's transl)]

One hundred and forty-one patients for general and urological surgery were anaesthetized by epidural anesthesia (PDA) using bupivacaine-CO2 0.5% solutions. A frequency peak for the initial dose between 21-23 ml was noted. The response time and latency period were found to be 2.99 +/- 1.40 min and 11.02 +/- 3.66 min (smallest time unit 0.5 min). The effective duration was 5.02 +/- 0.93 h. The sensory spread reached on average to T 6.06 +/- 1.41 segments for the patients with typical injection locations at L2/3-L4/5. A mean dose of 6.25 +/- 0.18 mg per spinal segment was used. Side effects were not seen apart from occasional hypotension. The failures were not related to the anesthetic drug. The degree of muscle relaxation was for the majority of cases evaluated at 2 +, which was sufficient for the abdominal operations. The results are compared with the data obtained using bupivacaine-HC1; the advantages of bupivacaine-CO2 are described.

Investigations on the structure-activity relationships of verapamil

An investigation was carried out towards a qualitative and quantitative structure-activity relationship of verapamil based on an analysis of the frequency-dependent negative inotropic action exerted in cat papillary muscles by various groups of verapamil derivatives. (1) Substituents of the benzene ring near the asymmetric carbon atom and the isopropyl group were found to be no essential substituents for the frequency-dependent negative inotropic action of verapamil but to have a strong influence on the potency of the drug. (2) Both the tertiary amino nitrogen and the two benzene rings are essential for the frequency-dependent negative inotropic action of verapamil (3) The molecular importance of the N-methyl group is probably based on steric effects. (4) Investigations of the verapamil derivative H 1 revealed that a quaternization of the drug is followed by a total loss of effectiveness. (5) No significant correlation of the biological activity of verapamil derivatives with the partition coefficient P has been obtained. (6) Hansch analysis with verapamil derivatives of group A (= different substitution of the benzene ring near C) shows that the variance of biological activity can be optimally correlated to a combination of the Hammett constant and the molar volume. Hansch analysis of group B (= exchange of isopropyl group) led to the conclusion that hydrophobic effects are responsible for the influence of the isopropyl substituent.

Why does the cardiac force-velocity relationship not follow a Hill hyperbola? Possible implications of feedback loops involved in cardiac excitation-contraction coupling

1. If cardiac force-velocity (PV) relationships are determined in a rhythmically beating isolated preparation by progressively changing afterloads, the PV curves obtained exhibit a characteristic nonhyperbolic shape with an upward convexity in the force domain close to P0. It was suggested by others that this might be due to contractile element (CE) shortening against series elastic component (SEC) and/or the early decay of the active state at isometric peak tension. 2. The present investigation performed in isolated cat papillary muscles demonstrates that neither CE shortening against SEC nor the variation of the intensity of the active state can fully account for the nonhyperbolic shape of cardiac PV curves. 3. On the other hand large parts of the remaining deviation could be eliminated if the "progressive loading sequence" (PLS) was replaced for an "interpolated loading sequence" (ILS). Here, the muscle contracts under steady state conditions either isometrically or isotonically (zero load). Single afterloaded test contractions are interpolated after every 10th beat. 4. It is concluded that the nonhyperbolic shape of cardiac PV curves, determined by progressively changing afterloads, is the expression of at least four factors: (i) the existence of displacement dependent variation of excitation-contraction coupling (including the contraction-excitation-contraction recoupling loop), (ii) CE shortening against non CE bound SEC, (iii) a variable active state and (iiii) a fourth unknown mechanism.

[Concerning the casuistics by aspiration of waste oil sediments (author's transl)]

When cleaning an underground waste oil dump, an 18 year old worker suffered loss of consciousness by inhaling vapours of trichloroethylene and then suffocated by aspiration of waste oil sediments. Histological examination of the lungs proved the copious presence of partly granulous darkish-brown and of rather light coloured crystalloid foreign substances up to the multiple size of erythrocytes. "Chemical examination of blood, brain and urine showed the presence of trichloroethylene and its metabolites, respectively. The trichloroethylene concentration has been determined in the brain."

[Aortic abnormalities in Marfan's syndrome]

Three different forms of aortic lesions in Marfan's Syndrome are demonstrated: 1. moderately severe aortic valve insufficiency due to sinus of Valsalva aneurysm; 2. severe aortic valve insufficiency due to aneurysmal widening of the ascending aorta; 3. an unusually wide dissecting aneurysm extending from the aortic root to the aortic bifurcation. A review of the current literature of the changes in Marfan's Syndrome is given. It is obvious that early diagnosis of the cardiovascular changes is important for the patient's prognosis, allowing the optimal time for surgical intervention to be chosen.

[Cerebral ischemia or post traumatic thrombosis of the A. carotis occuring to a car driver (author's transl)]

A short while after leaving a public-house a 71 year old man as the driver of his car was involved in a head-on collision with another car. On admission to a hospital he was unconscious with a distinct debility for the left side of his body and showed a changing anisocoria. Angiography of the right carotid artery revealed an occlusion. It was suspected that this was the terminal state of a generalized arteriosclerotic occlusion which was considered being the reason for the accident. The autopsy-findings showed, however, a posttraumatic thrombosis (whiplash-trauma of the cervical vertebral column) of the right arteria carotis and of the right arteria vertebralis with thromboembolia in a small pontine artery with an infarct-like ischemic softening. The differentiation from an apoplexia is of importance for the differential diagnosis.

[Age determination of post traumatic changes in menisci and synovium (author's transl)]

Morphological examinations on 259 surgically removed menisci, 67 for trauma after soccer. Degenerative changes in menisci are more pronounced after a longer time intervall between trauma and surgery.

Reversible alterations in the mitotic cycle of chick embryo cells in various states of growth regulation

Chick embryo cells which have been kept overnight at pH 6.8 in the absence of serum multiply very slowly. Only a small fraction of cells is in the S period at any given time, and the rate of uptake of 2-deoxy-D-glucose is very low. Upon raising the pH to 7.4 and adding serum ("turn-on") the uptake of 2-deoxy-D-glucose increases immediately; the rate of DNA synthesis increases after a lag of about 4 hours, and represents an increase in the fraction of cells synthesizing DNA. the uptake of 2-deoxy-D-glucose is rapidly returned to its original low rate at any time by again lowering the pH and removing serum ("turn-off"). The synthesis of DNA in the culture remains constant or continues to rise at a markedly reduced rate following the same treatment. Lowering pH or removing serum independently of each other is less efficient at inhibiting the increase in DNA synthesis than the combined treatment but each accomplishes a similar result. Cultures which have been "turned-off" during the early stages of the rapid increase in DNA synthesis, resume their prior rate of increase immediately if "turned-on" again within 2.5 hours. If the cultures have been "turned-off" for 5.5 hours before restoring the "turn-on", there is a 2 hour delay before they resume an increased rate of DNA synthesis. The results until shortly before, or at the time of the onset of the S period. Up to 96% of the cells in post-confluent cultures growing in conventional medium become labeled upon continuous, prolonged exposure to 3H-thymidine. Seventy-eight percent of the cells in serum-deprived cultures growing at a very low rate become labeled. These and other considerations suggest that the inhibition of cell multiplication by high population density or serum deprivation is caused by a lengthening of the time cells remain in the prereplicative G1 period rather than by shifting cells into a qualitatively distinct G0 period. There may, however, be a period common to all cells regardless of growth rate, in which cells are not progressing toward the S period. The length of this variable period would then determine the growth rate of a population of cells.

Radiographic evaluation of patients with schistosomiasis

Plain films of the abdomen in advanced states of schistosomiasis reveal massive splenomegaly without evidence of splenic calcification. The liver may be enlarged in the early stages but ultimately decreases and becomes small. Ascites is evident in far advanced disease. Chest films are negative in the early stages, but in advanced disease, dilated pulmonary arteries, right ventricular enlargement, and dilatation of the azygous vein may be recognized. Granulomata are seen as multiple small rounded densities scattered throughout both lung fields. The routine barium swallow will reveal unsuspected esophageal varices. Nine patients were studied preoperatively by panhepatic angiography and 14 post-operatively following splenorenal shunt. Thrombosis of the shunt and hepatic encephalopathy were common postoperative complications.