Hepatic micrometastases of the parenchyma adjacent to a macroscopic lesion were detected in 17 of 31 resected liver metastases.
Fifty-nine micrometastatic lesions were detected in total; 26 lesions were situated in the portal vein (PV), 22 in the central
vein (CV), 5 in the bile duct (BD), and 6 in the sinusoid (SS). A histological study confirmed the direct invasion of the
macrometastatic cancer cells into the adjacent PV, CV, BD, and SS. According to the tumor doubling time, the mean diameter
of the macrometastases in 19 remnant livers was calculated to have been 0.57±0.87 cm at the time of the primary resection.
The calculated diameter of 3 of these 19 macrometastases was found to be less than 0.01 cm, the minimum implantable size,
indicating that the cancer recurrence in these specimens may have developed from macroscopic metastatic lesions as a satellite,
and not from the primary tumor. In 13 patients who received doses of 5250 mg or more of 5 fluorouracil (FU) via the hepatic
artery, the cumulative disease-free rate 2 years postoperatively was 100%; this value was 47.6% in 11 patients who received
less than 5250 mg of 5 FU via the hepatic artery, and 0% in 39 patients who received no chemotherapy (P<0.005). These results suggest that anatomical hepatic resection for satellite lesions, combined with prophylactic hepatic
arterial chemotherapy for micrometastases, decreases the recurrence rate of hepatic metastases in the remnant liver. 相似文献
The purpose of this study was to investigate the effect of natural interferon (IFN) on the expression of placental alkaline
phosphatase (PLAP) in a human seminoma xenograft in severe combined immunodeficient mice. Mice were injected intramuscularly
with 3 × 105 U/mouse of IFN, twice a day, for five consecutive days. A significant increase in PLAP level of the xenografts followed IFN
treatment. A radiolabeled anti-PLAP monoclonal antibody (MAb) was intravenously injected on the first day of IFN administration
in order to determine if IFN has the potential to enhance the efficacy of an anti-PLAP MAb in the detection of seminoma. Enhanced
retention of the anti-PLAP MAb was observed at 7 and 11 days after MAb administration. Thus, IFN treatment appears to have
some effect on the efficacy of the anti-PLAP MAb in the detection of seminoma xenografts.
Received: 26 September 1997 / Accepted: 23 April 1998 相似文献
Background: Although halothane directly inhibits platelet aggregation, the mechanisms of this effect are still unknown. The current study aimed to clarify the inhibitory mechanisms of halothane on thrombin-induced human platelet aggregation by measuring (1) platelet-surface glycoprotein Ib expression, (2) the concentration of intracellular free Calcium2+ ([Calcium2+]i) measured simultaneously with aggregation, (3) the concentration of intracellular inositol 1,4,5-triphosphate, and (4) the concentration of intracellular cyclic 3',5'-adenosine monophosphate ([cAMP]i).
Methods: Washed platelet suspensions, obtained from healthy volunteers, were preincubated with halothane (0-2 mM) for 2 min and then exposed to 0.02 units/ml thrombin for 3 min. The glycoprotein Ib bound to fluorescein-labeled antibody was measured by fluorescence flow cytometry. [Calcium2+]i was measured, simultaneously with aggregation, in Fura-2 (Calcium2+ indicator)-loaded platelets by use of a fluorometer. Inositol 1,4,5-triphosphate and [cAMP]i were measured by radioimmunoassay.
Results: Halothane had no effect on glycoprotein Ib expression with or without thrombin. Halothane decreased the thrombin stimulated [Calcium sup 2+]i transient and inhibited platelet aggregation in a dose-dependent manner, both in the presence and in the absence of external Calcium2+. Isoflurane had no apparent effect on either platelet aggregation or [Calcium2+]i in the absence of external Calcium sup 2+. Halothane inhibited the increase in inositol 1,4,5-triphosphate induced by thrombin. Halothane moderately but significantly increased [cAMP]i, but the adenylate cyclase activator forskolin (which has the same inhibitory ability on aggregation as halothane) increased [cAMP]i to a much greater extent than did halothane. 相似文献
The effect of halothane and enflurane on tracheal tone were studied in 21 patients during the induction of anesthesia. Endotracheal tube cuff pressure was used to measure tracheal tone. Anesthesia, maintained by nitrous oxide 70% in oxygen, was supplimented with succinylcholine drip infusion to immobilize the patient. Ventilation was controlled by a Volume-preset ventilator. In the halothane group, the initial cuff pressure was 14.8 ± 1.3 (mean ± SE) cmH2O but 10min after 0.15mg/kg of pancuronium injection, it increased to 21.7 ± 2.3cmH2O (control). Ten min after inhalation of 0.75% of halothane, cuff pressure decreased to 14.7 ± 2.3cmH2O (34 ± 11% decrease from the control value). In the enflurane group, the initial cuff pressure was 17.6 ± 1.8cmH2O and it increased to 21.0 ± 1.7cmH2O (control) 10min after pancuronium injection. Ten min after 1.7% of enflurane inhalation, cuff pressure decreased to 17.1 ± 2.3cmH2O (23.9 ± 6% decrease from the control value). Halothane and enflurane produced similar tracheal dilatation in healthy individuals.(Yasuda I, Irimada M, Hirano T et al.: Tracheal dilatation by halothane and enflurane in man. J Anesth 2: 46–49, 1988) 相似文献
The activation and inactivation relations of several ion channel currents overlap, suggesting the existence of a steady-state or "window" current. We studied L-type Ca2+ channel window current in single cardiac Purkinje cells using a voltage-clamp protocol by which channels were first inactivated nearly completely during a long-duration depolarizing step, and then the recovery of Ca2+ current was observed during repolarizing steps into the L-type Ca2+ window voltage range. With these conditions, a small-amplitude inward Ca2+ current gradually developed after repolarization to voltages within the window but not after steps to voltages positive or negative to it. Window current was suppressed by Cd2+ (50 microM), nifedipine (1 microM), and nicardipine (1 microM), and it was augmented by isoproterenol (5 microM) and Bay K 8644 (1 microM). At voltages at which window current developed, L-type Ca2+ channels also recovered to a closed state from which they could be reopened by an additional depolarizing step. At voltages positive to the window range, channel recovery to a closed state(s) was absent, whereas at voltages negative to the window range, channel recovery to a closed state(s) increased, as expected from the "steady-state" inactivation relation. Our results provide direct measurement of L-type Ca2+ window current and distinguish it from other processes, such as slow inactivation. Our findings support the postulate that within a window there occur channel transitions from inactivated to closed states, and these channels (re)open, and this process may occur repetitively. Some physiological and pathophysiological roles for L-type Ca2+ window current are discussed. 相似文献
The skin, particularly the opercular membrane of some teleosts, contains mitochondrion-rich "chloride" cells and has been widely used as a model to study branchial salt-extrusion mechanisms in seawater fish. Skin isolated from the operculum of the freshwater Nile tilapia (Oreochromis niloticus) can transport Ca2+ against an ionic and electrical gradient. Adaptation of Nile tilapia to a low-Ca2+ environment increased the capacity of the opercular membrane to transport Ca2+. The density of mitochondrion-rich cells increased in parallel with Ca2+ transport capacity. The results demonstrate net Ca2+ uptake by vertebrate skin and strongly implicate mitochondrion-rich cells as the site of Ca2+ uptake in fresh water. 相似文献
Recently, it has been shown that in most clinical cases of parasystole, the parasystolic rhythm is not completely independent of the sinus rhythm. In this study, to disclose the mechanism of such "irregular" parasystole, parasystolic cycles with an intervening sinus QRS complex (XSX) were compared with their immediately adjacent pure parasystolic cycles without any intervening nonparasystolic QRS complexes (XX) in 10 cases of ventricular parasystole. In eight cases, the XSX interval was equal to or nearly equal to the adjacent pure XX interval; in one, the XSX interval was shorter than the XX interval; and in only one, the XSX interval was longer than the XX interval. In six cases in which the XSX interval was almost equal to the XX interval, calculated XSX intervals with a later intervening sinus QRS complex were obtained from the differences between the XSSX interval (ie, interectopic interval with two intervening sinus QRS complexes) and its adjacent XX interval. In five of the six cases, the calculated XSX interval was shorter than the XX interval. These observations suggest that in most cases of parasystole, early intervening sinus impulses do not change the parasystolic cycle, whereas late intervening sinus impulses shorten the parasystolic cycle. This suggests the presence of type I second-degree entrance block as the mechanism of "irregular" parasystole. 相似文献