Further studies on the mechanism of adrenaline-induced lipolysis in lipid micelles.
Lipase [EC 126.96.36.199] depleted lipid micelles, in which lipolysis was not elicited by adrenaline, were prepared from lipid micelles. When these lipase-depleted lipid micelles incubated with adipose tissue extract containing lipase activity, adrenaline-induced lipolysis was restored to almost the same level as that of native lipid micelles. Adrenaline-induced lipolysis was not restored when the lipase-depleted lipid micelles were homogenized or sonicated. Various tissue extracts from kidney, lung, liver, and pancreas, and post-heparin plasma, which contained lipase activity, restored adrenaline-induced lipolysis in lipase-depleted lipid micelles. (+info)
Sentinel lymph node biopsy and axillary dissection in breast cancer: results in a large series.
BACKGROUND: Axillary lymph node dissection is an established component of the surgical treatment of breast cancer, and is an important procedure in cancer staging; however, it is associated with unpleasant side effects. We have investigated a radioactive tracer-guided procedure that facilitates identification, removal, and pathologic examination of the sentinel lymph node (i.e., the lymph node first receiving lymphatic fluid from the area of the breast containing the tumor) to predict the status of the axilla and to assess the safety of foregoing axillary dissection if the sentinel lymph node shows no involvement. METHODS: We injected 5-10 MBq of 99mTc-labeled colloidal particles of human albumin peritumorally in 376 consecutive patients with breast cancer who were enrolled at the European Institute of Oncology during the period from March 1996 through March 1998. The sentinel lymph node in each case was visualized by lymphoscintigraphy, and its general location was marked on the overlying skin. During breast surgery, the sentinel lymph node was identified for removal by monitoring the acoustic signal from a hand-held gamma ray-detecting probe. Total axillary dissection was then carried out. The pathologic status of the sentinel lymph node was compared with that of the whole axilla. RESULTS: The sentinel lymph node was identified in 371 (98.7%) of the 376 patients and accurately predicted the state of the axilla in 359 (95.5%) of the patients, with 12 false-negative findings (6.7%; 95% confidence interval = 3.5%-11.4%) among a total of 180 patients with positive axillary lymph nodes. CONCLUSIONS: Sentinel lymph node biopsy using a gamma ray-detecting probe allows staging of the axilla with high accuracy in patients with primary breast cancer. A randomized trial is necessary to determine whether axillary dissection may be avoided in those patients with an uninvolved sentinel lymph node. (+info)
Transport of colloidal particles in lymphatics and vasculature after subcutaneous injection.
This study was designed to determine the transport of subcutaneously injected viral-size colloid particles into the lymph and the vascular system in the hind leg of the dog. Transport of two colloid particles, with average size approximately 1 and 0.41 microm, respectively, and with and without leg rotation, was tested. Leg rotation serves to enhance the lymph flow rates. The right femoral vein, lymph vessel, and left femoral artery were cannulated while the animal was under anesthesia, and samples were collected at regular intervals after subcutaneous injection of the particles at the right knee level. The number of particles in the samples were counted under fluorescence microscopy by using a hemocytometer. With and without leg rotation, both particle sets were rapidly taken up into the venous blood and into the lymph fluid. The number of particles carried away from the injection site within the first 5 min was <5% of the injected pool. Particles were also seen in arterial blood samples; this suggests reflow and a prolonged residence time in the blood. These results show that particles the size of viruses are rapidly taken up into the lymphatics and blood vessels after subcutaneous deposition. (+info)
Perineuronal nets of proteoglycans in the adult mouse brain, with special reference to their reactions to Gomori's ammoniacal silver and Ehrlich's methylene blue.
As our previous studies have indicated, many subsets of neurons in the vertebrate brain possess a sulfated proteoglycan surface coat which reacts to cationic iron colloid and aldehyde fuchsin. The present study demonstrated that this surface coat is supravitally stained with Ehrlich's methylene blue, and doubly with this blue and aldehyde fuchsin, a finding suggesting its being identical to Cajal's superficial reticulum (red superficial) and to Golgi's reticular coating (revetement reticulare). The perineuronal surface coat was further stained with Gomori's ammoniacal silver, and doubly with this silver and cationic iron colloid. These neurons with such a proteoglycan surface coat usually expressed cell surface glycoproteins which were labeled with lectin Wisteria floribunda agglutinin. Hyaluronidase digestion did not interfere with this lectin labeling of the glycoproteins, methylene blue and Gomori's ammoniacal silver staining of the surface coat, while it erased the cationic iron colloid and aldehyde fuchsin staining of the surface coat. These findings suggest that the perineuronal proteoglycan surface coat is associated with some additional molecules which are resistant to hyaluronidase digestion and stainable with methylene blue and Gomori's ammoniacal silver. The possibility is suggested that these molecules might represent "ligand proteoglycans" connecting the perineuronal proteoglycans and cell surface glycoproteins. (+info)
Failure of amphotericin B colloidal dispersion in the treatment of paracoccidioidomycosis.
Although amphotericin B desoxycholate is considered the most effective treatment for disseminated Paracoccidioides brasiliensis infections, little is known about the efficacy of lipid-based formulations of amphotericin B in this infection. In this study, we treated four adults with the juvenile form of paracoccidioidomycosis with 3 mg/kg/day of amphotericin B colloidal dispersion for at least 28 days. Although all of the patients initially responded by clinical observation, all four patients relapsed within six months. The use of amphotericin B colloidal dispersion for the initial induction of paracoccidioidomycosis failed to cure this infection. Possible reasons for failure include dose, duration, or reduced efficacy of this lipid preparation. For many fungal infections, lipid-based preparations have been shown to have a therapeutic-toxic advantage, but our experience with Paracoccidioides infections suggests that more careful studies will need to be performed before they can be recommended for use in this mycosis. (+info)
Osmotic pressure contribution of albumin to colloidal interactions.
Two surfaces that come in close contact in a solution with macromolecules present experience an attractive force caused by the osmotic pressure. We present a measurement of this effect by using a micrometer-sized sphere bound to a flat plate through a single molecular attachment in an albumin-containing solution. We obtain the osmotic part of the interaction potential with a resolution of <1 nm and a fraction of kTroom. This attractive interaction is seen to have a range comparable to the size of the albumin molecule. The results are broadly in agreement with a geometric model first proposed by Asakura and Oosawa. (+info)
The metabolic effects of estriol in female rat liver.
The effects of estriol on oxygen uptake, glucose release, lactate and pyruvate production, beta-hydroxybutyrate and acetoacetate production in perfused rat liver as well as, carbon uptake in rat liver and intracellular calcium in isolated Kupffer cells were investigated. Basal oxygen consumption of perfused liver increased significantly in estriol or ethanol-treated rats. But these increased effects were blocked by gadolinium chloride pretreatment. In a metabolic study, pretreatment with estriol resulted in a decrease in glucose production and in glycolysis while an increase in ketogenesis. A more oxidized redox state of the mitochondria was indicated by increased ratios of perfusate [lactate]/[pyruvate] and decreased ratios of perfusate [beta-hydroxybutyrate]/[acetoacetate]. Carbon uptake of Kupffer-cell increased significantly in estriol-treated rats. But these increased uptake were not shown in rats pre-treated by gadolinium chloride blocking phagocytosis. In isolated Kupffer cells from estriol-treated rats, intracellular calcium was more significantly increased after addition of lipopolysaccharide (LPS) than in controls. These findings suggest that the metabolic effects of estriol (two mg per 100 mg body wt) can be summarized to be highly toxic in rat liver, and these findings suggest that oral administration of estrogens may induce hepatic dysfunctions and play a role in the development of liver disease. (+info)
Phase I and pharmacologic study of 9-aminocamptothecin colloidal dispersion formulation in patients with refractory or relapsed acute leukemia.
PURPOSE: Topoisomerase I inhibitors have shown promising anti leukemic activity in acute myelogenous leukemia (AML) and myelodysplastic syndrome. In this phase I study, we investigated the toxicity profile, pharmacokinetics, and activity of a prolonged continuous infusion schedule of the colloidal dispersion formulation of 9-amino-camptothecin (9-AC/CD) in patients with acute leukemia. PATIENTS AND METHODS: Patients with refractory or relapsed AML, acute lymphocytic leukemia (ALL) or chronic myelogenous leukemia in blastic phase (CML-BP) were included in the study. Eligibility criteria were age greater than 15 years, performance status of 2 or better, creatinine < 1.5 mg/dl, and bilirubin < 1.5 mg/dl. 9-AC/CD was given as a continuous intravenous infusion over seven days every three to four weeks. The starting dose was 0.2 mg/m2/d (1.4 mg/m2/course). Courses were given every three to four weeks according to toxicity and anti leukemic efficacy. This phase I study used the classical 3 + 3 design. The dose was escalated by 50% until grade I toxicity was observed, and then by 30% to 35% until the dose limiting toxicity was defined. At the maximal tolerated dose (MTD), 8 to 10 patients were planned to be treated to better define the toxicity and early-activity profiles. RESULTS: Thirty-nine patients (AML thirty-six patients; ALL two patients; CML-BP one patient), median age 56 years, were treated. Severe mucositis was the dose limiting toxicity; it occurred in three of six patients treated at a dose of 1.6 mg/m2/d. The MTD was defined as 1.4 mg/m2/day by the phase I design. Upon expansion of the number of patients, 3 of 10 patients had grade 4 mucositis and 1 of 10 patients had grade 3 diarrhea. Nausea and vomiting were uncommon. No complete or partial remission was observed in 37 evaluable patients. However, 9-AC/CD exhibited antileukemic activity, as reflected by the finding of marrow hypoplasia on day 14 in 46% of the patients. Average steady-state concentration of 9-AC lactone was close to 10 nmol/l, and the of 9-AC lactone area under curve (AUC) was 1409 +/- 705 nmol/l. hr. CONCLUSION: The MTD of 9-AC/CD given as a seven-day continuous infusion was 1.4 mg/m2/d (9.8 mg/m2/course) in patients with acute leukemia. This represents three to fourfold dose escalation compared with the MTD of 9-AC given as shorter continuous infusion (three days) in patients with solid tumors. Future studies will determine the activity of prolonged administration of 9-AC/CD in patients with better prognosis acute leukemia. (+info)