Oral 18F-fluoro-2-deoxyglucose for primate PET studies without behavioral restraint: demonstration of principle

We describe a method of orally administering 18F-fluoro-2-deoxyglucose (FDG) for positron emission tomography (PET) scans to determine local cerebral metabolic rates for glucose (LCMRGlc), normalized to that of whole brain, in fully conscious, non-restrained primates. Oral FDG-PET studies were performed in both non-restrained and chaired monkeys, and in one human where results could be compared with traditional intravenous FDG administration. The oral route of FDG administration gave images and whole brain-normalized PET LCMRGlc results comparable to those obtained by the intravenous route. This oral FDG-PET method may provide a useful means by which to obtain measures of LCMRGlcs for brain structures, relative to each other, in non-restrained, non-drugged primates in field and laboratory studies. This method might also have clinical applications for PET studies of children.

The role of formalin-induced pain in morphine tolerance, withdrawal, and reward

The effect of a commonly used experimental pain-induction procedure (formalin injection into a hindpaw site) on morphine tolerance, withdrawal, and reward was examined in rats. Results suggest that the effects of morphine are different in the organism that is experiencing pain at the time it receives the drug than in the organism that is pain free. The presence of pain at the time of each morphine administration decreased analgesic tolerance, decreased naloxone-precipitated withdrawal, and enhanced the rewarding effect of the opiate. These findings, together with those of previous studies, suggest that theories of opiate tolerance, withdrawal, and reward should incorporate the effects of pain.

(AC)23 [Z-2] polymorphism of the aldose reductase gene and fast progression of retinopathy in Chilean type 2 diabetics

A recent case-control study suggests that the allele (AC)23 of a variable number tandem repeat (VNTR) associated to the aldose reductase (ALR2) gene could be related to early retinopathy in Type 2 diabetics. By means of a longitudinal-retrospective study, we aimed to seek for a relationship between the rate of progression of retinopathy and the (AC)23 allele of the VNTR associated to the ALR2 gene. A random sample was obtained of 27 Type 2 diabetics (aged 68.1 +/- 10.6 years, diabetes duration = 20.7 +/- 4.8 years, mean HbA1 = 10.6 +/- 1.6%). The mean HbA1 was the arithmetic average of 2.2 measurements per patient per year of total glycosilated hemoglobin (Gabbay method, normal range: 4.2-7.5%). Retinopathy was graded by an Ophthalmologist in a scale from zero to four score points. The genotype of the (AC), VNTR was determined by 32P-PCR plus sequenciation in a Perkin-Elmer laser device. The Mann-Whitney test and either chi2 or Fisher's exact test were used. A P < 0.05 was considered as statistically significant. The retinopathy progression rate (RPR, points x year(-1)) was calculated by dividing the increment of retinopathy score (delta Retinopathy Score, [points]), by the duration of the follow up [years]. The 12 diabetics having the (AC)23 allele had a mean RPR 8.9 times higher (0.40 +/- 0.61 points x year(-1)) than the 15 patients who had alleles other than (AC)23 (0.045 +/- 0.099 points x year(-1), P = 0.037). Both groups were similar with respect to: mean HbA1 (10.5 +/- 1.4 and 10.7 +/- 1.7%, P = 0.95), age at diagnosis (48.5 +/- 6.3 and 46.3 +/- 14.0 years, P = 0.81), diabetes' duration (21.3 +/- 4.7 and 20.2 +/- 4.9 years, P = 0.41) and serum creatinine (0.89 +/- 0.2 and 1.13 +/- 0.5 mg dl(-1), P = 0.35). We concluded that, in Type-2 diabetics having similar glycemic control, the (AC)23 allele of the VNTR associated to the ALR2 gene, is associated to a 8.9 times faster progression of retinopathy than in patients who have other alleles.

Drug-onset cues as signals: intraadministration associations and tolerance

On the basis of a conditioning analysis of drug tolerance, drug-associated cues become associated with the drug effect. These cues elicit conditional compensatory responses and modulate the expression of tolerance. Although there are many findings consistent with the conditioning analysis of tolerance, there also are contrary findings. The results of these experiments suggest that some of the apparently contradictory findings result because interoceptive pharmacological cues, as well as exteroceptive environmental cues, are paired with a drug effect. That is, within each administration, early drug-onset cues may become associated with the later, larger drug effect, and these pharmacological cues may overshadow simultaneously present environmental cues. We demonstrate the contribution of such intraadministration associations to tolerance to the analgesic effect of morphine and to the expression of conditional compensatory hyperalgesia.

Drug anticipation and drug addiction. The 1998 H. David Archibald Lecture

Environmental cues associated with drug use become capable of eliciting withdrawal symptoms, craving and relapse to drug self-administration. The phenomenon, although noted almost 150 years ago, has repeatedly been confirmed in epidemiological and experimental studies. Drug tolerance, which is closely correlated with withdrawal symptoms and craving, is also modulated by drug-associated environmental cues. The contribution of predrug cues to withdrawal and tolerance is emphasized in a Pavlovian conditioning analysis of drug administration. Drug-induced disturbances are modulated by homeostatic responses elicited by pharmacological stimulation. According to the conditioning analysis, we learn to anticipate the drug effect; corrective response (conditional compensatory responses) occur in the presence of situations and events that have been associated with the drug in the past. These conditional responses, seen in anticipation of drugs, importantly contribute to drug tolerance, failures of tolerance (enigmatic overdoses), and withdrawal symptoms. I review evidence indicating that a complete analysis of drug withdrawal and tolerance requires an appreciation of the contribution of Pavlovian conditioning.

Feasibility and safety of peripheral blood stem cell collection in children with poor-prognosis solid tumors: a single center experience

This study reports the data of 32 children with poor-prognosis solid tumors who had 78 PBSC harvests on Fenwall CS-3000plus after mobilization mainly by different treatment protocol chemotherapy regimens followed by G- or GM-CSF (92% of patients) or by G-/GM-CSF alone (8%). Timing of procedure was predicted by studying the blood count. When the white blood cell and platelet count reached a median of 8.1 (0.9-37.3) and 95 (16-338) x 10(9)/L, respectively, the median number of 2.7 (0.005-16.8) x 10(6) CD34+/kg with 1.5 (0.005-11.6) x 10(6) CD34+/kg for 1 blood volume processed was obtained per procedure. In the group of 13 patients with low body weight (median 14 [10-20] kg) 32 leukophereses were performed. The extracorporal line was primed with donor red blood cells in the patients with the weight below 15 kg. No difference was observed in CD34+ content in harvests whether GM-CSF was begun on day +1 or on day +3 after chemotherapy.

Systemic mastocytosis with involvement of the pelvis: a radiographic and clinicopathologic study--a case report

The musculoskeletal manifestations of systemic mastocytosis have been described in the literature. We present a case of systemic mastocytosis involving the pelvis. Conventional radiographs and CT imaging may demonstrate diffuse sclerotic, or mixed lytic and sclerotic lesions. On MRI, the lesions, if sclerotic, may show low signal on T1- and T2-weighted images. However, if lytic, the lesions may demonstrate low signal on T1, and increased signal on T2. As there are numerous disease entities included within the differential diagnosis, the clinical and pathological findings are crucial for establishing the correct diagnosis.

Multiple chemical sensitivity as a conditional response

Pavlovian conditioning may contribute to some cases of multiple chemical sensitivity (MCS). On the basis of the conditioning analysis, environmental stimuli (especially olfactory cues) present at the time of a toxicant overdose become associated with the toxicant and elicit aversive conditional responses. Similar associations have been reported in patients receiving chemotherapy, and the literature on such 'pretreatment nausea' in cancer patients is relevant to understanding the role of conditioning in MCS. Evaluation of the contribution of conditioning to MCS has been complicated by confounding interpretations that emphasize conditional responses with interpretations which emphasize the psychiatric status of the patient. Appreciation of the contribution of Pavlovian conditioning to MCS will lead to a better understanding of this complex disorder.

Onset and duration of action of levocabastine nasal spray in atopic patients under nasal challenge conditions

BACKGROUND

Although prior studies have documented the rapid onset of action of topical intranasal levocabastine (LEV), little is known about its duration of action under nasal challenge conditions.

OBJECTIVES

We sought to assess the onset and duration of action of escalating doses of LEV nasal spray by using a nasal allergen challenge (NAC) model.

METHODS

Eighteen asymptomatic subjects with histories of seasonal allergic rhinitis were enrolled into a randomized, single-blind, placebo-controlled, dose-ranging crossover study. Each patient was randomly assigned to receive single doses of placebo and intranasal LEV 0.1, 0.2, and 0.4 mg during 2 parts of the study. In part 1 (onset of action), NAC consisted of a single dose of allergen administered 5 minutes after study drug treatment. In part 2 (duration of action), NAC consisted of increasing doses of allergen administered 0.5, 6, 12, and 24 hours on separate days after study drug treatment. Nasal symptom scores (NSSs) and nasal peak expiratory flow rates were measured after NAC in both phases of the study. Blood samples for plasma LEV concentrations were drawn after each NAC.

RESULTS

In part 1, NSSs were significantly lower after the administration of LEV 0.1, 0.2, and 0.4 mg compared with placebo (P <.05). In part 2, NSSs were significantly lower after LEV doses of 0.2 and 0.4 mg compared with placebo at 0.5, 6, 12, and 24 hours after treatment (P <.05). The mean provocative dose of allergen required to elicit a positive nasal reaction was increased after LEV doses of 0.2 and 0.4 mg at 0.5, 6, and 12 hours after treatment. Nasal peak expiratory flow rates demonstrated no significant differences between LEV and placebo for any doses at any time points. Mean plasma LEV concentrations were low (range, 0 to 3. 7 ng/mL) after all doses and did not correlate with drug efficacy.

CONCLUSIONS

Single intranasal LEV doses of 0.1, 0.2, and 0.4 mg significantly reduced the severity of the immediate nasal response to allergen when administered 5 minutes before NAC. This protective effect against NAC continued to be present 24 hours after administration of LEV doses of 0.2 and 0.4 mg. Efficacy in blocking the reaction to NAC did not correlate with plasma LEV levels, suggesting that the inhibitory effect was due largely to topical rather than systemic effects.

Performance characteristics of a compact position-sensitive LSO detector module

We assembled a compact detector module comprised of an array of small, individual crystals of lutetium oxyorthosilicate:Ce (LSO) coupled directly to a miniature, metal-can, position-sensitive photomultiplier tube (PSPMT). We exposed this module to sources of 511-keV annihilation radiation and beams of 30- and 140-keV photons and measured spatial linearity; spatial variations in module gain, energy resolution, and event positioning; coincidence timing; the accuracy and sensitivity of identifying the crystal-of-first-interaction at 511 keV; and the effects of intercrystal scatter and LSO background radioactivity. The results suggest that this scintillator/phototube combination should be highly effective in the coincidence mode and can be used, with some limitations, to image relatively low-energy single photon emitters. Photons that are completely absorbed on their first interaction at 511 keV are positioned by the module at the center of a crystal. Intercrystal scatter events, even those that lead to total absorption of the incident photon, are placed by the module in a regular "connect-the-dot" pattern that joins crystal centers. As a result, the accuracy of event positioning can be made to exceed 90%, though at significantly reduced sensitivity, by retaining only events that occur within small regions-of-interest around each crystal center and rejecting events that occur outside these regions in the connect-the-dot pattern.

Pre-drug cues modulate morphine tolerance, striatal c-Fos, and AP-1 DNA binding

To evaluate the molecular mechanisms that mediate the effect of learning on morphine tolerance in rats, we examined striatal c-Fos, and c-Jun protein expression, and AP-1 DNA binding. Morphine paired with a conditioned stimulus (CS) led to analgesic tolerance in the presence of the CS. Rats receiving morphine unpaired with the CS displayed significantly less tolerance than paired morphine animals. Striatal c-Fos protein levels and AP-1 DNA binding activity were increased in rats receiving paired morphine compared with rats that did not receive morphine but not in rats receiving morphine without the CS. No differences were found in c-Jun levels. These results suggest that Pavlovian conditioning may account, in part, for the molecular mechanisms associated with morphine tolerance.

Surface Behavior of Spread Sodium Eicosanyl Sulfate Monolayers

The surface behavior of spread sodium eicosanyl sulfate monolayers is characterized by determining the dilational moduli from different pi/A isotherms and from surface stress relaxation experiments in the short-time range (<10 min). The elasticities derived from the pi/A isotherms differ depending on the experimental conditions. The quasi-equilibrium isotherm displays a plateau in the range of coexistence of the condensed and the expanded phases and strong increases caused by the formation of a solid-like phase. In contrast, nonequilibrium pi/A isotherms yield effective elasticities showing a maximum within the phase coexistence range. The formation of a solid phase cannot be detected because of the onset of monolayer collapse. Different stress relaxation experiments were carried out for monolayer compression and dilation using transient drop volume jumps. Depending on the experimental run, these experiments lead to consistent and complementary results with those derived from pi/A isotherms under comparable conditions. The stress recoveries yield a relaxation time, a dilation viscosity, and a parameter characterizing the homogeneity of the relaxation process. The stress relaxation is interpreted accounting for both the nonequilibrium between the monolayer and the bulk phase and the nonequilibrium within the monolayer. The influence of alkylsulfate hydrolysis on the presented results was checked. It was found that within the time scale of the experiments no influence of hydrolysis could be detected. Copyright 1998 Academic Press.

Learning and tolerance to the ataxic effect of ethanol

It has been well documented that drug-associated cues are important for the development and expression of drug tolerance. The Pavlovian conditioning analysis of tolerance emphasizes the importance of a drug-associated cues to tolerance by equating a drug administration with a learning trial. According to this analysis, tolerance should be subject to external inhibition, the disruption of a conditional response by a novel stimulus. We previously reported that tolerance to the ataxic effect of ethanol was attenuated by a novel strobe/noise presentation (31). In this article we report evidence of a compensatory CR in rats tolerant to the ataxic effect of ethanol as tested on the tilting plane. Both the compensatory CR and tolerance were disrupted by the presentation of a novel strobe/noise stimulus providing converging evidence that the attenuation of tolerance by a novel stimulus results from external inhibition of Pavlovian conditioning. The disruption of ethanol tolerance and the conditional response mediating tolerance was also apparent when the novel omission of the strobe/noise stimulus was used as the external inhibitor in rats made tolerant to ethanol with the stimulus on. Finally, we have shown that the disruptive effect of a novel stimulus on ethanol tolerance is decreased when there is a 10-day delay between the final tolerance development session and testing, demonstrating that the interval between training and testing is important when assessing associative tolerance.

Learning and homeostasis: drug addiction and the McCollough effect

The contribution of conditioned responses (CRs) to homeostasis may be seen by examining seemingly disparate phenomena of color vision (aftereffects and chromatic adaptation) and drug addiction (withdrawal symptoms and tolerance). Color aftereffects may be elicited by nonchromatic stimuli previously paired with color (the McCollough effect, [ME]). Similarly, pharmacological aftereffects may be elicited by nonpharmacological stimuli previously paired with a drug (withdrawal symptoms). The authors summarize evidence indicating that both the ME and withdrawal symptoms are CRs. The chromatic CR is expressed as chromatic adaptation in the presence of color, and the ME in the absence of color. The pharmacological CR is expressed as pharmacological adaptation (tolerance) in the presence of the drug, and withdrawal symptoms in the absence of the drug. Both drug withdrawal symptoms and the ME are manifestations of the contribution of conditioning to normal homeostatic regulation. The authors discuss the implications of this conclusion for understanding regulatory processes and the evolution of behavioral mechanisms.

Credit analysis of nonprofit continuing care retirement communities

The continuing care retirement community (CCRC) industry's growth has gained the attention of the financial community. As the industry's financial and regulatory environments change, credit analysts are developing analytical tools to evaluate these changes. The following article discusses some of these tools, provides a sample credit profile of a CCRC, and reviews recent accounting changes that will affect CCRC credit analysis.

Conditioned sucrose aversions produced by naloxone-precipitated withdrawal from acutely administered morphine

The aversive properties of acute naloxone-precipitated morphine withdrawal were examined in the taste reactivity paradigm. Acute naloxone-precipitated withdrawal paired with sucrose solution established conditioned active rejection of the sucrose solution. Active rejection of sucrose was observed when naloxone was administered both 1 h and 22 h after morphine. When the stimulus properties of morphine were present during the conditioning trial, the conditioned sucrose aversion was only expressed when the rats were tested in the same drug state in which they had learned the aversion. However, when the stimulus properties of morphine were not present during conditioning, the aversion was expressed in the absence of the morphine state. The results suggest that palatability shifts can be conditioned to sucrose paired with acute morphine withdrawal.