Antitumor and immunotherapeutic effects of activated invasive T lymphoma cells that display short-term interleukin 1alpha expression

Expression of cytokines in malignant cells represents a novel approach for therapeutic treatment of tumors. Previously, we demonstrated the immunostimulatory effectiveness of interleukin 1alpha (IL-1alpha) gene transfer in experimental fibrosarcoma tumors. Here, we report the antitumor and immunotherapeutic effects of short-term expression of IL-1alpha by malignant T lymphoma cells. Activation in culture of T lymphoma cells with lipopolysaccharide-stimulated macrophages induces the expression of IL-1alpha. The short-term expression of IL-1alpha persists in the malignant T cells for a few days (approximately 3-6 days) after termination of the in vitro activation procedure and, thus, has the potential to stimulate antitumor immune responses in vivo. As an experimental tumor model, we used the RO1 invasive T lymphoma cell line. Upon i.v. inoculation, these cells invade the vertebral column and compress the spinal cord, resulting in hind leg paralysis and death of the mice. Activated RO1 cells, induced to express IL-1alpha in a short-term manner, manifested reduced tumorigenicity: approximately 75% of the mice injected with activated RO1 cells remained tumor free. IL-1 was shown to be essential for the eradication of activated T lymphoma cells because injection of activated RO1 cells together with IL-1-specific inhibitors, i.e., the IL-1 receptor antagonist or the M 20 IL-1 inhibitor, reversed reduced tumorigenicity patterns and led to progressive tumor growth and death of the mice. Furthermore, activated RO1 cells could serve as a treatment by intervening in the growth of violent RO1 cells after tumor take. Thus, when activated RO1 cells were injected 6 or 9 days after the inoculation of violent cells, mortality was significantly reduced. IL-1alpha, in its unique membrane-associated form, in addition to its cytosolic and secreted forms, may represent a focused adjuvant for potentiating antitumor immune responses at low levels of expression, below those that are toxic to the host. Further assessment of the immunotherapeutic potential of short-term expression of IL-1alpha in activated tumor cells may allow its improved application in the treatment of malignancies.

Efficacy of nonfetal human RPE for photoreceptor rescue: a study in dystrophic RCS rats

This study determines the efficacy of nonfetal human retinal pigment epithelium (RPE) for photoreceptor rescue utilizing the dystrophic RCS rat as an animal model. Eyes from 10- and 49-year-old donors were obtained through the Rochester Eye and Human Parts Bank. The RPE was isolated by enzymatic treatment of the choroid-RPE with 2% dispase for 30 min at 37 degrees C. Mechanically dissociated RPE cells were injected at the superior hemisphere into the subretinal space of dystrophic RCS rats during the fourth postnatal week. Rats receiving vehicle injection served as sham controls. The animals were immunosuppressed with daily cyclosporine injections (10 mg/kg) and sacrificed 30 days posttransplantation for histologic evaluation of the RPE graft and its effect on photoreceptor survival. Transplantation of adult human RPE promoted the survival of photoreceptors in the dystrophic RCS rat. Morphometric analysis of the grafted superior hemisphere demonstrated a threefold increase in photoreceptor cell density (149.2 +/- 50 SD) compared to sham controls (39.7 +/- 31 SD) and the untouched inferior hemisphere (52.8 +/- 28 SD). RPE from the 49-year-old donor was as effective as RPE from the 10-year-old donor in promoting photoreceptor survival. The results of this study in RCS rats suggests that RPE from adult human donors of varied ages is suitable for transplantation and retains the capability to promote survival of photoreceptor cells. This finding opens the possibility of using nonfetal RPE cells in human retinal transplantation.

Estrogenic effects on urinary 6-sulphatoxymelatonin excretion in the female rat

The pattern of melatonin production during the estrous cycle of the rat was measured by monitoring urinary 6-sulphatoxymelatonin (aMT.6S) excretion. Adult rats were maintained under a 14L:10D photoperiod and urine was collected at hourly intervals over a 5-day period using an automated collection system; the concentration of aMT.6S was assayed by RIA and hourly outputs were calculated. Each nightly collection of urine was assigned to an estrous cycle stage as determined by the vaginal smear of the preceding morning. Total aMT.6S excretions (mean +/- SEM) during estrous, metestrous, diestrous, and proestrous stages were 493 +/- 49, 539 +/- 44, 562 +/- 40, and 646 +/- 51 pmol/night, respectively (n = 7). The excretion of aMT.6S was significantly higher on the night of proestrus compared to each of the other stages (P < 0.05). To determine whether estrogen was responsible for the increased aMT.6S excretion during proestrus, rats were studied before and after ovariectomy and following implantation with estradiol implants. Total overnight aMT.6S excretion was reduced by 31% in ovariectomized animals relative to the intact state (P < 0.05) and restored to the intact levels by administration of estradiol (P < 0.05). It was concluded that estradiol can modulate melatonin production in adult rats, and that the changing pattern of aMT.6S excretion throughout the estrous cycle may provide a basis for a functional relationship between pineal activity and reproduction in this species.

A source model for efficient brachytherapy computations with Monte Carlo

Monte Carlo techniques have the potential for producing accurate brachytherapy dose distributions in heterogeneous finite geometries. However, for routine clinical use, computational speed must be adequate. A fast, all-particle, CT-based Monte Carlo code called PEREGRINE is being developed at Lawrence Livermore National Laboratory for radiation treatment planning. As one feature, the code will produce accurate dose distributions from brachytherapy sources in heterogeneous geometries. For efficiency, brachytherapy sources in this model are treated as points or line segments. Radiation is emitted with the proper energy spectrum and (perhaps anisotropic) angular distribution. In particular, for anisotropic emission the polar angle is determined by a random-number driven empirical function constructed from a source's measured or precomputed fluence emission pattern. Source model parameters are presented for iodine and iridium sources. While designed for the PEREGRINE program, this source model can be used in any Monte Carlo code.

A phase I study of methotrexate administration following 5-fluorouracil

A priming dose of 5-fluorouracil can decrease the toxicity and retain the efficacy of high-dose methotrexate in laboratory models. This Phase I study determined the maximum tolerated dose of methotrexate that can be administered after a dose of 5-fluorouracil without leucovorin rescue. Forty-two patients received 5-fluorouracil (500 mg/m2) by bolus injection followed in 2 h by methotrexate infused over 1 h; treatment was repeated every 3 weeks. Patients received five doses of leucovorin (10 mg/m2 every 6 h); this was reduced to two doses and then to zero doses (no rescue) if less than grade 2 toxicity occurred in prior treatments. If safe, at least two patients received no leucovorin rescue with their first treatment. The dose of methotrexate was escalated in cohorts of patients, starting with a methotrexate dose of 200 mg/m2. Previously untreated patients maximally tolerated 1600 mg/m2 of methotrexate with 5-fluorouracil pretreatment. Leukopenia combined with stomatitis prevented deescalation of leucovorin doses. Fourteen percent of total courses and 15% of courses without leucovorin rescue resulted in dose limiting toxicity. MTX levels exceeded levels that require leucovorin rescue. Four of the 33 (12%) advanced head and neck cancer patients had objective responses to therapy; median survival was 10 months. Previously treated patients were less tolerant; oral and hematological toxicities were troublesome; 400 mg/m2 of methotrexate was the approximate maximum tolerated dose. Forty-seven percent of total courses and 60% of courses without leucovorin rescue resulted in dose limiting toxicity. There were no responses. Although the antineoplastic activity is poor, prior 5-fluorouracil exposure does protect tissues susceptible to methotrexate toxicity.

Epidural hematoma of a cauda equina in a child with hemophilia A

PURPOSE

The presenting signs, treatment, and outcome of an epidural hematoma of the cauda equina in a child with severe hemophilia are reported for the first time.

PATIENTS AND METHODS

A 20-month-old boy with severe hemophilia A (factor VIII <0.01 U/ml) presented with a 12-day history of refusal to stand and constipation of 5-7 days duration. He had normal deep tendon reflexes with normal sensation and withdrawal to pinprick of his lower extremities bilaterally. He stood on his right leg, but had inversion of his left foot and refused to bear weight on his left leg. MRI revealed an epidural hematoma of the cauda equina and a distended bladder. Factor VIII replacement therapy and lumbosacral laminectomy with evacuation of the hematoma resulted in recovery of a normal gait, but bladder dysfunction persisted for 11 months. Clean intermittent catheterization (CIC) was required until bladder function returned.

RESULTS

Complete neurologic recovery occurred 11 months after presentation

CONCLUSION

This case demonstrates the following points: (a) an epidural hematoma of the cauda equina in a child with severe hemophilia can present with neurologic findings that are as subtle as those seen in normal children; (b) CIC can be performed safely over an extended period without factor VIII replacement; and (c) complete recovery is possible, despite prolonged bladder dysfunction and a 12-day interval between the onset of symptoms and treatment.

Differential contribution of endothelial function to vascular reactivity in conduit and resistance arteries from deoxycorticosterone-salt hypertensive rats

The purpose of these studies was to compare changes in conduit and resistance artery function in deoxycorticosterone-salt hypertensive rats. We hypothesized that if there was a common mechanism producing changes in vascular function in hypertension, then there would be similar alterations in reactivity of conduit and resistance arteries. Helically cut strips of common carotid artery were prepared for measurement of isometric force generation, and segments of small mesenteric arteries were pressurized for video dimension analysis. Sensitivity of arteries to phenylephrine and acetylcholine was determined. Carotid arteries from deoxycorticosterone-salt hypertensive rats were more sensitive to phenylephrine than arteries from control rats, whereas mesenteric resistance arteries from hypertensive rats were less sensitive to phenylephrine. In carotid arteries, endothelial denudation or incubation with N psi-nitro-L-arginine increased phenylephrine sensitivity in control rats to the level seen in deoxycorticosterone-salt rats. These manipulations had no effect on phenylephrine sensitivity in arteries from deoxycorticosterone-salt rats. In mesenteric resistance arteries, endothelium denudation normalized the depressed phenylephrine sensitivity in arteries from hypertensive rats but had no effect on arteries from normotensive rats. This depressed phenylephrine sensitivity in deoxycorticosterone-salt mesenteric arteries was not reversed by incubation with Npsi-nitro-L-arginine. Acetylcholine-induced relaxation was depressed in carotid arteries from deoxycorticosterone-salt hypertensive rats, and Npsi-nitro-L-arginine blocked these relaxations. In contrast, acetylcholine relaxation in the mesenteric arteries from normotensive and hypertensive rats did not differ. N psi-nitro-L-arginine slightly but significantly attenuated acetylcholine dilation only in mesenteric resistance arteries from the hypertensive rats. We conclude that qualitatively different changes in vasoconstrictor sensitivity to phenylephrine occur in carotid arteries and mesenteric resistance arteries of deoxycorticosterone-salt hypertensive rats. The increased phenylephrine sensitivity in carotid arteries in this model of hypertension is due to the loss of endothelium-derived nitric oxide production. In contrast, the decreased phenylephrine sensitivity in mesenteric resistance arteries from deoxy-corticosterone-salt rats is due to a non-nitric oxide-mediated influence of the endothelium that is absent in arteries from normotensive rats.

Prognosis in HIV-1 infection predicted by the quantity of virus in plasma

The relation between viremia and clinical outcome in individuals infected with human immunodeficiency virus-type 1 (HIV-1) has important implications for therapeutic research and clinical care. HIV-1 RNA in plasma was quantified with a branched-DNA signal amplification assay as a measure of viral load in a cohort of 180 seropositive men studied for more than 10 years. The risk of acquired immunodeficiency syndrome (AIDS) and death in study subjects, including those with normal numbers of CD4+ T cells, was directly related to plasma viral load at study entry. Plasma viral load was a better predictor of progression to AIDS and death than was the number of CD4+ T cells.

Interleukin-6 release following scorpion sting in children

Interleukin-6 levels were measured in the serum of ten children following severe scorpion envenomation. Measurements were taken on arrival, at the emergency room, and 12 and 24 hr after arrival. Interleukin-6 was markedly elevated in the serum of eight out of ten children on arrival. Interleukin-6 levels gradually decreased toward normal values on 12 and 24 hr measurements, but remained above control levels on all measurements. These results imply that signs and symptoms following scorpion envenomation may in part be explained by release of cytokines. Human and experimental animal studies are required in order to verify the assumption that interleukin-6 and other cytokines are involved in the pathogenesis of scorpion envenomation.

Complementary organ expression of IL-1 vs. IL-6 and CSF-1 activities in normal and LPS-injected mice

The specific expression of pro-inflammatory cytokines may affect the functioning of organs in different ways. The results of specific cytokine bioassays used in this study show a distinct pattern of tissue expression of IL-1 IL-6 and CSF-1. Cytokine activity was assessed in conditioned media (CM) and lysates (LYS), obtained from different organs of control or lipopolysaccharides (LPS)-injected mice; LPS representing a potent inflammatory stimulus. Low constitutive levels of IL-1 could be demonstrated only in CM/LYS from organs with lymphoreticular function, such as the liver, spleen, intestine and lungs. On the other hand, IL-6 and CSF-1 were mainly detected in the CM (and not in lysates) of organs, such as the heart, kidneys, muscle and brain. LPS injection basically resulted in an accentuated form of the constitutive pattern. CSF-1 displays a similar pattern of expression to that of IL-6, best detected in CM after LPS stimulation. Thus, a mirror-image relationship emerges between the patterns of IL-1 and IL-6/CSF-1 expression in two groups of organs: those with lymphoreticular function, which manifest high IL-1 and low IL-6/CSF-1 activity, as compared to organs characterized by highly specialized and potentially vulnerable functions (such as the heart, brain, muscle and kidney), which exhibit high IL-6/CSF-1 and low IL-1 activity. Due to their defensive functions, lymphoreticular organs, which are in charge of the 'gates of entry' to the body, mount extensive IL-1-mediated inflammatory responses, even at the cost of possible tissue-damage. On the other hand, the more vulnerable internal organs mount IL-6/CSF-1-mediated responses which are milder and bear less potential for tissue damage. The distinct patterns of expression of pro-inflammatory cytokines in different organs, at steady state or under inflammatory conditions, may shed light on tissue characteristic homeostatic and defence mechanisms.

Reproductive seasonality of the bush rat (Rattus fuscipes greyi) South Australia

The reproductive seasonality of the bush rat (Rattus fuscipes greyi) was investigated in Scott Creek Conservation Park near Adelaide, South Australia, by catch and release trapping conducted at irregular intervals over a 4-year period in a population of higher density than previously reported for this species. A seasonal pattern in breeding activity was observed with the production of young in spring and summer (October-February) with a peak in December. There was seasonal variation in the testicular index of males with minimal values from April to June. Some animals may have retained the ability to mate throughout the year but there was no evidence of offspring surviving from any winter matings. Differences were seen in the timing and intensity of the non-breeding season between years. Possible causes of reproductive seasonality were seasonal changes in vegetative growth and the abundance of fungi and insects and predictive cues provided by seasonal changes in ambient temperature and photoperiod.

5-fluorouracil modulates the toxicity of high dose methotrexate

Pretreatment with 5-fluorouracil (FU) attenuated the toxicity of high dose methotrexate (MTX) in in vitro and in vivo models. Because dose intensification of the MTX reversed the fluoropyrimidine antagonism of MTX activity in these models, administering FU before the MTX offered the potential advantage of MTX dose intensity and low toxicity without the confounding effects of leucovorin rescue. The current study was conducted to determine the maximum dose of MTX tolerated after a priming dose of FU without leucovorin rescue, and to determine the toxicities of this combination. Subjects (n = 42) received a constant dose of FU followed in 2 hours by MTX; treatment was repeated every 3 weeks. Subjects initially received five doses of leucovorin (10 mg/m2 every 6 hours); this was reduced to two doses, then to zero doses (no rescue) if less than grade 2 toxicity occurred in prior treatments. Cohorts of subjects received escalating doses of MTX in a Fibonacci fashion. At the 1250 mg/m2 dose level, almost all previously untreated subjects tolerated the elimination of leucovorin rescue, without the occurrence of severe toxicity; this was 6 to 8 times the MTX dose that generally requires leucovorin rescue to avoid severe and lethal toxicity. The 24- and 48-hour MTX levels were at a level that usually requires leucovorin rescue. Previously treated subjects were less tolerant; 400 mg/m2 of MTX was the approximate maximum tolerated dose. Prior FU exposure appeared to protect tissues normally susceptible to MTX toxicity, and allowed safe administration of high dose MTX without leucovorin rescue.

Neurofibromatosis type 1: the evolution of deep gray and white matter MR abnormalities

PURPOSE

To investigate the evolution of deeply located high-signal-intensity abnormalities of the brain on T2-weighted MR images of patients with neurofibromatosis type 1 (NF-1).

METHODS

The study consists of two patient groups: 1) retrospective evaluation of MR scans of 24 symptomatic NF-1 patients, 10 of whom were sequentially studied, and 2) prospective MR evaluations of 20 asymptomatic NF-1 subjects from 14 families; 2 of these families were sequentially studied.

RESULTS

Deeply located, high-signal-intensity abnormalities on T2-weighted images were noted in 34 of 44 NF-1 subjects (77%). If NF-1 patients are grouped according to age, 28 of 30 subjects (93%) younger than 15 years had the lesions, whereas 4 of 7 subjects (57%) between 16 and 30 years, and 2 of 7 subjects (29%) older than 31 years had lesions. High-signal lesions in basal ganglia and brain stem were demonstrated in all decades with relatively high frequency. Lesions in the cerebellar white matter and dentate nuclei were mainly found in the patients younger than 10 years, and never found after the third decade. In 13 sequential studies (mean interval, 24 months), lesions appeared to increase in size in 3, remain unchanged in size in 2, and decrease in size in 7. One subject showed a mixed pattern of lesion size change.

CONCLUSIONS

Deeply located high-signal-intensity lesions on T2-weighted MR images are more evident in young NF-1 patients. The underlying brain abnormality, while pathologically unproved, is probably transient.

Biases in memory for and use of inconsistent beliefs in stereotyping

Some research has suggested that level of inconsistency of information that invalidates expectancy-based stereotypes or trait labels is one of several moderating variables that determine the memorability and use of inconsistent information (e.g. Rojahn & Pettigrew, 1992). Two experiments were designed to identify variables that moderate memory for and use of counter-stereotypic social-political beliefs that were attributed to a stereotypically identified group. In Expt 1, recall was found to be inversely related to level of inconsistency. In Expt 2, location of counter-stereotypic beliefs within a list and the order of counter-stereotypic beliefs (most-to-least vs. least-to-most inconsistent) determined the form of the relationship between recall and level of inconsistency. When counter-stereotypic beliefs were presented relatively early in a list and were ordered from least-to-most inconsistent, a positive relationship obtained; otherwise, the relationship was negative. Stereotyping was less extreme when counter-stereotypic beliefs were presented early in the least-to-most inconsistent ordering. Cognitive processes that may have produced these sets of findings were discussed.

Cytokine-induced tumor immunogenicity: endogenous interleukin-1 alpha expressed by fibrosarcoma cells confers reduced tumorigenicity

A direct correlation between the constitutive expression of IL-1 alpha and reduced tumorigenicity of fibrosarcomas was observed. This was established in fibrosarcoma cell lines which produce IL-1 alpha 'spontaneously', possibly as an aberration of oncogene-mediated transformation or upon IL-1 alpha gene transfer. In fibroblasts intracellular or membrane-associated IL-1 alpha is expressed, whereas the secreted form of the cytokine (IL-1 beta) is absent. Studies on the mechanisms of tumor regression of the IL-1 alpha-positive fibroblastoid cell lines indicated that IL-1 alpha potentiates the development of tumor cell-specific CTLs, which are of importance for tumor eradication. Thus, IL-1 alpha induces enhanced helper T cell activity which provides auxiliary signals for the growth/development of CTLs. Non-adaptive effector cells, activated locally by IL-1 alpha-expressing fibrosarcoma cells, also contribute to the eradication of IL-1 alpha-expressing fibrosarcomas. Local IL-1 alpha expression potentiated antigen presentation, by the malignant fibroblasts as well as by tissue-resident antigen-presenting cells, thus further potentiating anti-tumor immune responses. Mice, in which IL-1 alpha-producing tumors were regressed, developed an immune memory and rejected a challenge with an IL-1 non-producing violent tumor cell line. Endogenous IL-1 alpha activates a cytokine cascade (i.e., IL-6, CSF), produced by the malignant cells and possibly also by stromal cells. However, IL-1 alpha expression is essential for fibrosarcoma eradication, while other cytokines possibly amplify and sustain its action.(ABSTRACT TRUNCATED AT 250 WORDS)

Viscosity sensing with lamb-wave microsensor: dimethylsulfoxide solution viscosity as a function of temperature

Recently, a new microsensor employing low-velocity ultrasonic Lamb waves was developed and demonstrated to be capable of measuring the viscosity of solutions in small volumes. The microsensor, when attached to a temperature-controlled stage, can measure viscosity as a function of temperature. In this investigation, the ultrasonic Lamb-wave oscillator is employed to experimentally measure the viscosity of dimethylsulfoxide (Me2SO) solutions as a function of temperature. The microsensor and the experimental procedure are described and results for 1M, 3M, and 5M Me2SO aqueous solutions are presented. Dimethylsulfoxide is a compound commonly employed as a cryoprotectant in cryopreservation, the low-temperature preservation of biological materials. The temperature dependence of viscosity obtained through this study can be used in determining the probability for ice nucleation in biological materials, a parameter of importance during cryopreservation.