A role for the circadian clock of the suprachiasmatic nuclei in the interpretation of serial melatonin signals in the Syrian hamster.

Seasonal rhythms of reproduction in the Syrian hamster are triggered by the pineal hormone melatonin. By varying the parameters of systemic infusions of exogenous melatonin delivered to pinealectomized hamsters, it has been shown that the hypothalamus is sensitive to the duration of individual signals, which serve as an inverse coding of day length. It also has been shown that animals are sensitive to the temporal structure of a series of signals insofar as a series of melatonin infusions of appropriate number and duration may fail to invoke a gonadal response if they are presented at inappropriate frequencies.

Peripheral blood tyrosinase messenger RNA detection and survival in malignant melanoma.

Background: The most widely accepted criteria for the evaluation of prognosis of malignant melanoma are histopathologic and clinical presentation. No currently available laboratory tests provide additional prognostic information. It has recently been suggested that reverse transcription and polymerase chain reaction (RT-PCR)-based detection of tyrosinase messenger RNA (mRNA) in peripheral blood might be useful in the early detection of circulating tumor cells, since tyrosinase is thought to be a melanocyte-specific marker.

Entrainment of Syrian hamster circadian activity rhythms by neonatal melatonin injections.

The circadian rhythms of fetal and neonatal rodents are entrained by their mother. This entrainment is dependent upon the maternal suprachiasmatic nucleus (SCN), but the mechanism of entrainment is unknown. Administration of the pineal hormone melatonin to pregnant, SCN-lesioned female Syrian hamsters entrains the activity rhythms of their hamster pups.

Platelet endothelial cell adhesion molecule-1 (PECAM-1): a potential prognostic marker involved in leukocyte infiltration of renal cell carcinoma.

We investigated immunohistochemically the leukocyte infiltrate [CD3, CD4, CD8, CD11a, CD11b, CD14, CD56, VLA-4 and platelet endothelial cell adhesion molecule-1 (PECAM-1)] and the endothelial expression of cell adhesion molecules (PECAM-1, VCAM-1, ICAM-1 and ICAM-2) in 23 renal cell carcinoma tumor tissues. Tumors with a moderate or high density of PECAM-1 positive endothelia showed a stronger infiltration with PECAM-1-positive leukocytes as compared to tumors with a low density of positive endothelia (p<0.0085).

Exposure to vinblastine modulates beta 1 integrin expression and in vitro binding to extracellular matrix molecules in a human renal carcinoma cell line.

Solitary stroma-invading tumor cells expressing the ATP-binding cassette transporter P-glycoprotein have been reported to be associated with a significantly higher incidence of vessel invasion and lymph node metastases. In contrast to P-gp-mediated multidrug resistance (MDR) which has become well characterized over the last decade, little is known about further morphological and functional alterations in drug-resistant tumor cells. Binding of malignant cells to components of the extracellular matrix mediated by beta 1 integrins has been suggested to play a substantial role in the metastatic cascade.

Chromatographic techniques--the basis of doping control.

The principal definition of doping, the groups of banned compounds and the basic analytical problems and strategy of doping analysis are outlined, and the position of chromatography in doping analysis is explained. Examples of the application of GC-MS, especially high-resolution MS. and of LC-thermospray MS to doping problems are given.

Increased serum levels of basic fibroblast growth factor (bFGF) are associated with progressive lung metastases in advanced renal cell carcinoma patients.

Basic fibroblast growth factor (bFGF) has been detected in body fluids of patients with various malignancies including renal cancer. Cytoplasmatic expression of bFGF in primary renal cell carcinoma cells has been reported recently to correlate with an impaired patient survival. In the present study, we analysed the statistical association of spontaneous serum bFGF levels in 23 patients with advanced renal cell carcinoma and progressive metastasis in different organ sites.

Gonadal responses of the male tau mutant Syrian hamster to short-day-like programmed infusions of melatonin.

Changes in the duration of the nocturnal peak of the circadian rhythm of melatonin secretion by the pineal gland mediate pohotoperiodic control of reproductive cycles in mammals. The present study examined whether the tau mutation of the circadian clock of the Syrian hamster altered the ability of the animals to exhibit photoperiodic, gonadal responses to timed infusions of exogenous melatonin. Pinealectomized tau mutant and wild-type hamsters received s.

Methohexital impairs osmoregulation. Studies in conscious and anesthetized volume-expanded dogs.

Background: Anesthetic agents influence central regulations. This study investigated the effects of methohexital anesthesia on renal and hormonal responses to acute sodium and water loading in dogs in the absence of surgical stress.

Methods: Fourteen experiments (two in each dog) were performed in seven well-trained, chronically tracheotomized beagle dogs kept in highly standardized environmental and dietary conditions (2.

Lymphocyte-conditioned medium in combination with interleukin-2 effectively induces antitumour autoimmunity by adoptive transfer of short activated killer (SHAK) cells.

In this study, effective antitumour immunity was transferred by autologous short activated killer (SHAK) cells induced over four hours with lymphocyte conditioned medium (LCM) and recombinant interleukin-2 (rIL-2). Among eight patients with progressive metastatic renal cell carcinoma refractory to standard therapy, there were six objective tumour responses to SHAKs. Progression-free survival ranged from 0 to 8+ months, and overall survival ranged from 2 to 14+ months, with a median of 9+ months.

Behavioural and cellular responses to light of the circadian system of tau mutant and wild-type Syrian hamsters.

The tau mutation shortens the free-running circadian period of the activity rhythm of the Syrian hamster from around 24 h in the wild-type, to 20 h in the homozygous mutant. The aim of this study was to examine the effects of light pulses on the activity rhythms and expression of c-fos in the suprachiasmatic nuclei of wild-type and mutant hamsters. This would make it possible to determine the relative durations of subjective day and night, and thereby characterize further the effect of the mutation upon the circadian cycle.

In vivo tumor necrosis factor-alpha as indicator of biologic and clinical response to low-dose SC recombinant interleukin 2.

The effect of low-dose human recombinant interleukin-2 (rIL-2) on the induction of secondary tumor necrosis factor-alpha (TNF-alpha) in vivo was studied in 16 patients with metastatic renal cell carcinoma. In all patients s.c.

Immediate-early genes and the neural bases of photic and non-photic entrainment.

The expression of immediate-early genes (IEGs) within the mammalian suprachiasmatic nucleus (SCN) identifies individual light-responsive cells of the circadian system. Cells immunoreactive for products of IEGs form a neurochemically heterogeneous population, of which a few are VIP (vasoactive intestinal peptide)-immunoreactive or GRP (gastrin-releasing peptide)-immunoreactive, although the phenotypes of most of the others have yet to be determined. Dual-labelling experiments with anatomical tracers reveal that only a minority of efferent projection neurons of the SCN are immunoreactive for IEG products, and it is likely that the majority of the immunoreactive cells are interneurons or glia.

Platelet aggregation inhibiting and anticoagulant effects of oligoamines, XXIII: Influence of the oligoamine RE 1492 on the deformability of red blood cells.

The influence of the oligoamine RE 1492 on the deformability of Red Blood Cells (RBCs) was measured with the micropipette aspiration technique and the capillary rigidometer. The maximal cell flow resistance (MCFR) and the apparent elastic membrane shear modulus mu were increased by 45% at RE 1492 concentrations > 10 mumol/L. There was a decrease of the surface/volume ratio of 6% at RE 1492 concentrations of 25 mumol/L.

Soluble interleukin 2 receptors abrogate IL-2 induced activation of peripheral mononuclear cells.

Soluble interleukin 2 receptors (sIL-2R) exert a potential role in immunoregulation. We investigated the in vitro effects of sIL-2R on several interleukin 2 (IL-2)-dependent cellular events. Cytotoxicity of human rIL-2-stimulated PBMC against K562 and Daudi was correlated inversely to the concentration of sIL-2R in the culture medium during rIL-2 stimulation.

Immunocytochemical detection of P-glycoprotein: initial expression correlates with survival in renal cell carcinoma patients.

We evaluated 28 patients with advanced renal cell carcinoma for the initial expression of P-glycoprotein (MDR1 gene product) employing immunocytochemistry. Tumor specimens were obtained upon primary tumor nephrectomy. In all patients, progression-free survival time following nephrectomy was evaluated and correlated statistically with the staining results.

Induction of cytokines and cytotoxicity against tumor cells by Newcastle disease virus.

The use of NDV as biological adjuvant in vaccines against human cancer is still actual in several clinical treatment protocols. In this study, we have investigated in vitro-effects of Newcastle disease virus (NDV) strain 73-T on isolated mononuclear blood cells and cultured tumor cells. Cellular cytotoxicity of PBMC freshly isolated from healthy donors against tumor cells was enhanced significantly (p < 0.

In vivo time and dose dependency of interleukin-6 secretion in response to low-dose subcutaneous recombinant interleukin-2.

Serum concentrations of Interleukin-6 (IL-6) were determined in renal cell carcinoma patients treated with low-dose subcutaneous human recombinant interleukin-2 (rIL-2). In all patients, administration of rIL-2 resulted in a significant increase in IL-6 serum levels to peak values within 4 to 6 hours as measured by enzyme-linked immunosorbent assays (ELISA). Repetitive administration of rIL-2 induced significantly lower IL-6 serum peaks when compared to the initial administration of rIL-2.

Testicular regression in pinealectomized Syrian hamsters following infusions of melatonin delivered on non-circadian schedules.

The aims of this study were to validate the use of a timed infusion protocol for restoring physiologically appropriate rhythms of melatonin in the circulation of pinealectomized hamsters and, using such infusions, to compare the relative importance of the parameters of the nocturnal melatonin signal--frequency, phase, and duration of the interval between signals--in the photoperiodic control of testicular function in male Syrian hamsters. Hamsters were pinealectomized and fitted with a chronic s.c.

Pretreatment natural killer antigen density correlates to clinical response in tumor patients receiving long-term subcutaneous recombinant interleukin-2 and recombinant interferon-alpha.

We evaluated density of the natural killer (NK) cell-associated CD56 antigen on circulating NK cells of 47 patients with advanced renal cell carcinoma. Patients received a combination of low-dose subcutaneous recombinant interleukin-2 (rIL-2) and recombinant interferon-alpha (rIFN-alpha) as home therapy. Antigen density of CD56 before therapy was 2.

Non-photic phase shifting of the circadian activity rhythm of Syrian hamsters: the relative potency of arousal and melatonin.

This study investigated the relative potency of melatonin and arousal as Zeitgebers in the non-photic phase shifting of circadian rhythmicity in the adult Syrian hamster. Animals held under dim red light (DD) exhibited robust free-running rhythms of wheel-running activity. Melatonin (1 mg/kg) or ethanolic saline vehicle, delivered manually by subcutaneous injection after removing the animal from its cage, resulted in phase advances of the activity rhythm.

The effect of signal frequency on the gonadal response of male Syrian hamsters to programmed melatonin infusions.

The aim of this study was to investigate which characteristics of the nocturnal melatonin signal, in addition to its duration, convey photoperiodic information to the reproductive axis. To achieve control over the pattern of circulating melatonin, male Syrian hamsters held under stimulatory long daylengths (16h light:8h dark) were pinealectomized to remove the principal source of circulating endogenous hormone and then fitted with chronic subcutaneous cannulae through which programmed infusions of melatonin solution or vehicle could be delivered. Experiment 1 tested whether long intervals between successive melatonin signals impaired the photoperiodic response.

[A uterine rupture during peridural anesthesia].

A 31 years old multiparous woman was delivered by caesarean section at her first pregnancy. For her third, spontaneous, full-term labour an epidural analgesia was realized with 0.125% epinephrined bupivacaine and fentanyl (1 mg per kg).