Subcutaneous recombinant interleukin 2 in a dose escalating regimen in patients with metastatic renal cell adenocarcinoma.

Recombinant human interleukin 2 (rIL-2) was administered by s.c. injection daily, 5 days/week to patients with metastatic renal cell carcinoma in an escalating dose regimen. Fifteen patients were entered in this study and are evaluable for toxicity with one patient not evaluable for response because of lack of measurable disease. The patient population had a median age of 63 years with initial performance status (Southwest Oncology Group criteria) of 0 in one patient, 1 in eight patients, and 2 in six patients. The starting dose was 5 x 10(5) Cetus units/m2/day with dose escalation to 1 x 10(6), 2 x 10(6), 4 x 10(6), and 5 x 10(6) Cetus units/m2/day scheduled at 2-week intervals if no significant toxicity or response was noted. Six patients were treated with drug doses of 2 x 10(6) Cetus units/m2/day or higher with a maximum daily dose achieved of 2 x 10(6) units/m2 in two patients, 4 x 10(6) units/m2 in two patients, and 5 x 10(6) units/m2 in two patients. Fatigue with decrease in performance status and elevations in serum creatinine were the most common reasons for limiting the dose or removing a patient from the study. Only one minor anti-tumor response was seen. Subcutaneously administered rIL-2 was able to alter immunological parameters. In two of the three patients tested, development of lymphokine-activated killer cell activity in vivo was seen, and statistically significant enhancement of natural killer cell activity compared to values from a concurrently run normal control was demonstrated. With treatment, there was a trend toward increased numbers of circulating total lymphocytes, OKT 8+, OKT 11+, Leu 7+, and Leu 11a+ cells and decreased numbers of circulating OKT 3+ and OKT 4+ cells. However, for the heterogeneous group of six patients monitored, results were not statistically significant compared to pretreatment values. The levels of rIL-2-specific antibodies were followed in the sera of 10 patients. Six of the 10 developed rIL-2-specific IgG during treatment with five of the six patients also developing neutralizing activity. Recombinant human interleukin 2 given by the s.c. route in the doses and schedule used in this trial can safely be given as an outpatient regimen with manageable toxicity. It may result in enhanced immune function in some patients but also results in a high incidence of antibody formation.

Identification and selection of human lymphokine activated killer cell effectors and novel recycling intermediates by unique light-scattering properties.

When peripheral blood lymphocytes (PBL) are incubated with interleukin 2 (IL 2), a novel cytotoxic lymphocyte subpopulation, termed lymphokine activated killers (LAK), arises. LAK are functionally defined as IL 2 responsive cells demonstrating major histocompatibility antigen-unrestricted cell-mediated cytotoxicity against fresh solid tumors and other natural killer cell-resistant and -sensitive tumor targets in the absence of prior antigen priming. Flow cytometric analysis of IL 2 activated PBL using forward and right angle light scatter and fluorescence intensity identified the emergence of a large, optically dense, autofluorescent cell population which paralleled the generation of LAK activity. These unique IL 2 induced lymphocytes have been named giant autofluorescent lymphocytes (GAL). These cells are readily distinguished from the small nonfluorescent lymphocytes (SNL) observed in fresh PBL, unstimulated cultured PBL, and those cells remaining after incubation with IL 2 which have not acquired GAL characteristics. In this investigation, LAK cultures were sorted on days 4, 5, and 6 into GAL and SNL populations and were tested for oncolytic activity against the natural killer-resistant Daudi and RC-1 tumor targets. Against these targets, lymphocytes from non-IL 2 activated PBL or the sorted SNL population expressed less than 2% of the oncolytic activity (measured in lytic units) exhibited by GAL effectors. The SNL and GAL populations were cultured in IL 2 for up to 48 h following the sorting procedure and then reassayed for tumor cytolytic activity. During this culture period, GAL but not SNL continued to express LAK killing against natural killer-resistant tumor targets. Using gamma-irradiation to prevent further cell cycling, it was shown that the functional half-life of the LAK effector was approximately 8.5 h. Therefore, the cytotoxicity expressed by the sorted GAL population after 48 h in culture (equivalent to five functional half-lives) must be expressed by progeny of the originally plated lymphocytes. These results indicate that in addition to the LAK effector, the GAL population contains a self-sustaining, recycling intermediate responsible for generating new LAK. Our data indicate that analysis of IL 2 activated PBL using GAL light-scattering properties has application in phenotyping LAK, monitoring of cellular kinetics, cell sorting, and enrichment of the LAK effector population, and in the clinical monitoring of IL 2 therapy.

Population dynamics of the murine lymphokine activated killer system: precursor frequency and kinetics of maturation and renewal.

The proliferation kinetics and population renewal of recombinant interleukin-2 (rIL-2)-induced murine lymphokine activated killers (LAK) arising from splenic precursors was studied. Extensive proliferation has been shown to accompany the de novo generation of LAK cytotoxicity. In this report, a thymidine 'hot pulse' suicide technique was employed to examine the sensitivity of LAK progenitors during various time periods following culture initiation. Hot pulse during the first 24 hr of culture resulted in a 30-35% reduction in lytic activity when assayed on day 5. Pulse periods between days 1 and 4 resulted in almost complete inhibition (90-95%) of lytic function when assayed on day 5. Proliferation of LAK progenitors was documented by limiting dilution analysis comparison of splenic precursors and functionally mature LAK cultures. These studies showed a 75- to 80-fold enrichment of LAK progenitors after 3 days culture in rIL-2. By flow cytometric cell cycle analysis, we demonstrated that the number of cells in the S/G2/M phase increased with the length of rIL-2 culture and represented approximately 40% of the cells by day 4. Finally, we used the rate of decay of lytic activity following irradiation as a factor to define the mean life span of a cytotoxic effector in the absence of cellular input. An exponential decrease to approximately 50% of controls was observed within 8-9 hr after irradiation. Taken together, these results suggest that the LAK system is highly dynamic and requires continuous cellular proliferation for its maintenance.

Sensitive and selective assay for adenosine using high-pressure liquid chromatography with fluorometry.

A new method for quantitation of adenosine was tested in canine myocardial extracts. The method involves incubation of the extract with chloroacetaldehyde to form the fluorescing adenosine derivative 1, N6-ethenoadenosine. The ethenoadenosine is separated by high-pressure liquid chromatography (HPLC) and quantitated by fluorometry. Experiments demonstrated that 1) the method is selective for adenosine, 2) fluorescence peak height is linearly related to the quantity of ethenoadenosine, and 3) adenosine in the extract is quantitatively converted to ethenoadenosine by the incubation procedure. Also, within the range of adenosine concentrations seen in five extracts, estimates of myocardial adenosine content with the fluorometric method were nearly identical to those using the more routine technique of HPLC with direct detection by ultraviolet (UV) absorption. A primary advantage of the fluorometric method is its greater sensitivity. As little as 0.50 pmol on the column could be quantitated by fluorescence, compared with approximately 20 pmol with UV absorption. Because of the greater sensitivity, the fluorometric method should be more easily applied to samples with smaller adenosine concentrations.

Is love a necessary ingredient for sexual fulfilment?

PIP: Sexual intercourse and orgasm are regarded as a significant but not fundamental aspect of marital fulfillment. True sexual fulfillment arises from possessing and being possessed in a matrimonial state and can thus only exist in a stable and enduring marriage. Those who indulge in premarital intercourse, adultery, and masturbation for personal satisfaction will find such experiences shallow. Contraception is described as an act of violence against the natural reproductive process and as such, an act that cannot possibly foster love. Contraceptive intercourse is thought to be behind many marital breakdowns. The author acknowledges that his philosophy will on occasion lead to rearing a quite large family but feels such a family can provide a tremendous amount of love, satisfaction, and fulfillment, given that tasks involved are shared.^ieng

Principles of family planning for Roman Catholics.

PIP: The Church's moral teachings are logical and reasonable, and doctors should not have to prescribe contraceptives, perform sterilizations, or procure abortions. Patients should not be encouraged to break moral laws.^ieng