Continuous-wave synchronously pumped femtosecond dye laser at 1.3 microm

We report a synchronously pumped, cw mode-locked, near-IR dye laser based on the Kodak Q-switch dye No. 5. Benzyl alcohol is used as the solvent to form a flowing dye jet. Synchronously pumped by 2-psec, 950-mW, compressed pulses of a Nd:YAG laser, the dye laser can be tuned from 1210 to 1340 nm with a maximum output of 5 mW and a pulse duration of 600 fsec.

Flavivirus infection up-regulates the expression of class I and class II major histocompatibility antigens on and enhances T cell recognition of astrocytes in vitro

West Nile virus (WNV) infection of astrocytes can up-regulate their expression of both class I and class II major histocompatibility complex (MHC) antigens as determined by flow cytometry with monoclonal antibodies specific for class I and class II MHC antigens. The up-regulation of class I MHC antigen expression could be partly caused by interferon secreted after WNV infection because the synthetic interferon inducer polyinosinic-polycytidylic acid (poly I:C) has similar effects. In contrast the up-regulation of class II MHC antigen expression was not induced by poly I:C. The increased MHC antigen expression by WNV infection had significant effects on T cell recognition. Thus, WNV and influenza virus A/WSN double-infected astrocytes but not astrocytes infected by A/WSN alone were lysed by influenza virus-immune cytotoxic T cells. Similarly, WNV-infected astrocytes were better stimulators than normal astrocytes for a class II MHC-reactive T cell line, both in terms of T cell proliferation and interleukin release.

Isolation and characterization of a 58-kDa membrane- and microfilament-associated protein from ascites tumor cell microvilli

A 58-kDa protein is found in microvilli and in actin-containing transmembrane complexes of 13762 ascites tumor cells with immobile surface receptors; it is absent from sublines with mobile receptors. 58-kDa protein has been proposed to stabilize microvilli and restrict receptor mobility by stabilizing membrane-microfilament interactions. Antibodies against 58-kDa protein were blot-purified from antisera of rabbits injected with crude transmembrane complex and were used to monitor purification of the protein. 58-kDa protein was extracted from EDTA/EGTA-stripped microvillar microfilament cores with 1 M NaCl. A single depolymerization-polymerization cycle of the microfilaments, followed by solubilization of 58-kDa protein in 1 M NaCl and chromatography on hydroxyapatite-Sephadex G-150, purified the protein to greater than 95% homogeneity. The native molecular weight and frictional coefficient indicated a monomeric, asymmetric structure. 58-kDa protein bound F-actin in pelleting assays and inhibited polymerization of pyrenyl-actin. It also bound phosphatidylserine, phosphatidylinositol, and phosphatidylcholine vesicles in pelleting studies. Immunoblot analyses of endogenously and exogenously proteolyzed microvilli and their membranes and microfilament cores showed specific membrane and microfilament binding fragments of 28-30 kDa. The microfilament- and phospholipid-binding properties of 58-kDa protein and the localization of its proteolysis products are consistent with its proposed role in stabilizing membrane-microfilament interactions in the ascites cell microvilli.

In vitro evaluation of cisplatin interaction with doxorubicin or 4-hydroperoxycyclophosphamide against human gynecologic cancer cell lines

Doxorubicin, cisplatin, and cyclophosphamide are the three drugs most commonly used in the treatment of ovarian cancer, but no effect greater than additivity was observed for any combination of these drugs in the present study. Only a few studies have been reported concerning the degree of their additivity or their best order of sequencing. In our in vitro studies, cisplatin in combination with doxorubicin or 4-hydroperoxycyclophosphamide (4HC) was tested against seven human gynecologic tumor-cell lines in different sequences, using a double-agar layer tissue-culture system. Drug interactions with respect to inhibition of tumor clonogenicity were evaluated by isobologram and fractional survival methods. Doxorubicin and 4HC were sequenced simultaneously and at 1, 6 and 24 h after cisplatin, and cisplatin was sequenced at 1, 6 and 24 h after 4HC. The isobolograms constructed for doxorubicin or 4HC plus cisplatin revealed strict additivity between these agents against ovarian cancer clonogenicity. Both doxorubicin and 4HC showed the greatest additivity when used simultaneously and at 1 h vs 6 or 24 h after cisplatin. Although the mechanisms by which these sequencing effects occur are unknown, these studies provide new leads for the design of clinical trials with combinations of these three agents.

Studies on sensitivity of human GM-CFU and L-CFU to hyperthermic killing in vitro

The thermal sensitivity of normal myeloid and leukaemic cells was compared using morphology, cytochemistry and cultures of granulocyte-macrophage and leukaemic progenitor cells (GM-CFU and L-CFU). We have clearly demonstrated that blast cells from eight cases of acute nonlymphoblastic leukaemia (ANLL) showed greater morphological deterioration and loss of cytoplasmic enzymes with continuous heating at temperatures of 40-43 degrees C than normal marrow mononuclear cells obtained from ten controls. Survival of L-CFU also decreased exponentially with rising temperature whereas GM-CFU were not markedly affected, even at a temperature of 43 degrees C for 30 min. These results suggest that human L-CFU are more sensitive to hyperthermic killing than normal human GM-CFU and that hyperthermia might selectively purge residual leukaemic cells in vitro. Hyperthermia may have a role in clinical autologous bone marrow transplantation (ABMT) for acute leukaemia.

Relativistic cyclotron resonance shape in magnetic bottle geonium

The thermally excited axial oscillation of the electron through the weak magnetic bottle needed for the continuous Stern-Gerlach effect modulates the cyclotron frequency and produces a characteristic approximately 12-kHz-wide vertical rise-exponential decline line shape of the cyclotron resonance. At the same time the relativistic mass shift decreases the frequency by approximately 200 Hz per cyclotron motion quantum level n. Nevertheless, our analysis of the complex line shape shows that it should be possible to produce an abrupt rise in the cyclotron quantum number n from 0 to approximately 20 over a small fraction of 200 Hz, when the 160-GHz microwave drive approaches the n = 0 --> 1 transition, and a jump of 14 levels over a frequency increment of 200 Hz has already been observed in preliminary work. This realizes an earlier proposal to generate a very sharp cyclotron resonance feature by quasithermal excitation with a square noise band and should provide a way to detect spin flips when a weak bottle is used to reduce the broadening of the g - 2 resonance by a factor of 20.

Astrocytes are not susceptible to lysis by natural killer cells

A cell population from the central nervous system, of mainly astrocytes, was prepared and their susceptibility to natural killer cell lysis was compared to YAC-1 cells and L929 cells. Two populations of natural killer cells were used: the splenocytes of mice immunized with Semliki Forest virus 3 days previously and day 5 inflammatory cells from West Nile virus-infected CBA/H mouse brain. Both cell populations showed high lytic activity on YAC-1 cells and the effector cells possessed conventional natural killer cell markers, i.e., Thy1 +/-, L3T4-, Lyt2-, GM1+. The results revealed that astrocytes are not susceptible to lysis by natural killer cells and hence argue against the hypothesis that the absolute concentration of MHC antigens on the cell surface determines the susceptibility to natural killer cell lysis.

[Route and preparation of 5-Fu administration as preoperative adjuvant chemotherapy in rectal cancer. I. Concentration and distribution of 5-Fu in tissues monitored by 14C-isotopically tagged 5-Fu]

Experimental studies on more rational route and preparation of preoperative administration of 5-Fu were undertaken from March 1981 to June 1985. The experimental observation shows that intrarectal administration of radioisotope 14C tagged 5-Fu (suppository and emulsion) produces a much higher concentration in the rectal wall and mesenteric lymph nodes compared with its intravenous administration (40 rabbits) and produces a much higher concentration in cancer tissue than in surrounding tissues and in mesenteric lymph nodes than in the inferior mesenteric veins (4 patients). These findings favor the attenuation or destruction of cancer cells in the tumor and regional lymph nodes-the main route of spread. Also, after intrarectal administration of 14C tagged 5-Fu, its concentration in the lung, liver and bone marrow is much lower than that after intravenous administration (40 rabbits), and hence systemic toxicity is decreased. The above results indicate that the intrarectal route stands better than the conventional intravenous route for 5-Fu preoperative adjuvant chemotherapy in rectal cancer. Administration of 5-Fu emulsion produces a higher concentration in the rectal wall and mesenteric lymph nodes than that of 5-Fu suppository and peak concentration also appears earlier, i.e. 2 hours after the administration of 5-Fu emulsion. This will lessen the interference of 5-Fu absorption owing to its premature evacuation, indicating that emulsion is a better form for intrarectal 5-Fu.

Plasminogen San Antonio: an abnormal plasminogen with a more cathodic migration, decreased activation and associated thrombosis

An abnormal plasminogen (San Antonio) has been isolated from a patient with axillary vein thrombosis. A decreased level of fibrinolytic activity was detected in both plasma and a purified system. The molecular abnormalities were investigated with both functional and immunological tests. Slightly decreased antigen concentration was noted in plasma. By crossed immunoelectrophoresis, the patient and his two children had a second small arc and the primary arc migrated more cathodically. A distinct isozyme was detected in the abnormal plasminogen. Functionally, this abnormal plasminogen is characterized by failure to enhance maximal conversion to plasmin, especially by plasminogen activators, which are enhanced by fibrin or fibrin degradation products. The proband and his children are heterozygous for this abnormal plasminogen.

[Luteinizing hormone-releasing hormone (LRH) agonist in the treatment of breast cancer, osteosarcoma and prostate carcinoma--analysis of 12 patients]

This paper first reports the results of 12 patients with sex hormone-dependent neoplasms, including 9 women with breast cancer, 2 men with osteosarcoma and 1 man with prostate carcinoma, treated by LRH agonist, (D-Ala6, des-Gly-NH2(10))-LRH-ethylamide (LRH-A) 100-200 micrograms, IM, QD. After 15-30 days of administration, the concentrations of plasma mean estradiol, progesterone, testosterone, serum luteinizing hormone and follicle-stimulating hormone were lowered significantly in the peripheral blood of all patients, associating with improvement of the patients' general condition and reduction of the tumors and/or metastatic foci. No serious side effects were observed except vaginal irregular bleeding in isolated patients. Three patients died and the others were alive in follow-up of 4-30 months. The results suggest that LRH-A be useful in the treatment of the sex hormone-dependent tumors and worth further study.