Double-blind placebo-controlled trial of baclofen, alone and in combination, in patients undergoing voluntary abortion

This study evaluated the analgesic efficacy of baclofen in relation to specific pain stimuli in 83 women (27 nulliparas and 56 multiparas) undergoing voluntary abortion (clamping of the cervix and dilatation and curettage). The patient population was divided into five treatment groups as follows: group 1, placebo; group 2, baclofen, 0.3 mg/kg, administered intravenously (IV); group 3, baclofen, 0.6 mg/kg IV; group 4, baclofen, 0.3 mg/kg IV, and fentanyl, 1.5 mg IV; and group 5, baclofen, 0.3 mg/kg IV, and diazepam, 5 mg given orally and 5 mg IV. In each case the surgical intervention was started using analgesia only. When the first sensation of pain was recorded, a paracervical anesthetic block was performed to provide pain relief for completion of the operation. The results showed that baclofen had significantly better analgesic properties than did placebo, with no important side effects. Its analgesic action seemed to be dose-dependent, since better results were obtained with the higher dose. The analgesic effect was slightly potentiated when baclofen was combined with fentanyl, but not when it was combined with diazepam. Factors independent of the pain stimuli and drugs used--the most important being parity--influenced the results.     

Use of concurrent pupil dilation assessment to inform interpretation and analysis of fMRI data

Potential contributions of concurrently acquired pupil dilation data to functional magnetic resonance imaging (fMRI) experiments were examined. Sixteen healthy participants completed a working memory task (digit sorting) during measurement of pupil dilation outside the fMRI environment and during concurrent 3T fMRI assessment. Pupil dilation increased parametrically with task difficulty inside and outside the scanner, on a similar time course, suggesting that task demand was similar in both environments. The time course of pupil dilation during digit sorting was similar to the time course of the fMRI signal in the middle frontal gyrus, suggesting that middle-frontal gyrus activity indexed the engagement working memory processes. Incorporating individual differences in pupil dilation improved the sensitivity and specificity of general linear modeling analyses of activity in the middle frontal gyrus, above and beyond standard analytic techniques. Results suggest concurrent pupil dilation during fMRI assessment can help to (1) specify whether task demand is the same inside and outside the fMRI environment, (2) resolve the extent to which fMRI signals reflect different aspects of event-related designs, and (3) explain variation in fMRI data due to individual differences in information processing.     

Nurse staffing and patient falls on acute care hospital units

Changes in health care financing, beginning in the 1980's, resulted in reduced nurse staffing and skill levels in acute care hospitals. Research has shown that reduced nurse staffing has endangered some aspects of patient safety. This study estimated the relationship between three aspects of nurse staffing and the patient fall rate for four types of acute care units. The association was estimated using a generalized linear mixed model with data for 2002 from 1751 hospital units in the National Database of Nursing Quality Indicators. Higher fall rates were associated with fewer nursing hours per patient day and a lower percentage of registered nurses, although the relationship varied by unit type. Smaller hospitals also had higher fall rates. Information on unit type and different aspects of nurse staffing, with advanced statistical modeling, resulted in a more precise understanding of the relationship between nurse staffing and falls.     

Malignant hypercalcemia

Malignancy-associated hypercalcemia (MAH) is one of the clinical emergencies in medical oncology, arising early or, more often, during the late phases of disease. Prevalence cannot be estimated accurately because previous figures of 5-30% of all cancer patients have progressively reduced thanks to the widespread use of bisphosphonates for the prevention of skeletal events. The classic distinction of humoral vs. osteolytic hypercalcemia is still relevant from an etiological point of view, but should not be considered as a rigid alternative since both mechanisms may be active in the same patients and the activation of the RANKL pathway is a common pathogenetic mechanism. Parathyroid hormone-related protein mimics the effects of PTH on the bone and kidney (tubular calcium resorption) and may represent an attractive druggable target, but additional agents (cytokines or other mediators) as well as ectopic production of 1,25(OH)?D? may give an important contribution to humoral hypercalcemia. Conversely, bone invasion by cancer cells determines massive bone reabsorption due to the release of proteolytic enzymes and pro-osteolytic agents with paracrine activity on adjacent bone and stromal cells. When cancer patients develop headache, confusion, de-hydration and tremors hypercalcemia should be suspected although slow rise of calcium levels may produce more indolent symptoms. Bisphosphonates (with or without hydration and diuretics) may efficiently control MAH but only if an active treatment for the underlying cancer is promptly started. The anti-RANKL monoclonal antibody denosumab represents a novel agent able to revert the vicious cycle of bone metastases and data from phase III studies are currently showing promising activity in reverting bone resorption with manageable toxicity.     

Pentoxifylline modifies three-dimensional collagen lattice model contraction and expression of collagen types I and III by human fibroblasts derived from post-burn hypertrophic scars and from normal skin

Fibroblasts are thought to be partially responsible for the persisting contractile forces that result in burn contractures. Using a monolayer cell culture and fibroblast populated collagen lattice (FPCL) three-dimensional model we subjected hypertrophic scar and non-cicatricial fibroblasts to the antifibrogenic agent pentoxifylline (PTF – 1 mg/mL) in order to reduce proliferation, collagen types I and III synthesis and model contraction. Fibroblasts were isolated from post-burn hypertrophic scars (HSHF) and non-scarred skin (NHF). Cells were grown in monolayers or incorporated into FPCL's and exposed to PTF. In monolayer, cell number proliferation was reduced (46.35% in HSHF group and 37.73% in NHF group, p < 0.0001). PTF selectively inhibited collagen III synthesis in the HSHF group while inhibition was more evident to type I collagen synthesis in the NHF group. PTF also reduced contraction in both (HSHF and NHF) FPCL.     

1-Benzyl-1,2,3,4-Tetrahydroisoquinoline, an Endogenous Parkinsonism-Inducing Toxin, Strongly Potentiates MAO-Dependent Dopamine Oxidation and Impairs Dopamine Release: Ex vivo and In vivo Neurochemical Studies

1-Benzyl-1,2,3,4-tetrahydroisoquinoline (1BnTIQ), an endogenous neurotoxin, is known to cause a parkinsonism-like syndrome in rodents and primates. In this study we evaluated the effects of single and multiple 1BnTIQ (50 mg/kg i.p.) administration on the concentrations of dopamine, serotonin, and respective metabolites (homovanillic acid, HVA; 3,4-dihydroxyphenylacetic acid, DOPAC; 3-methoxytyramine, 3-MT; and 5-hydroxyindolacetic acid, 5-HIAA), in substantia nigra, striatum (STR), and nucleus accumbens of Wistar rats. In addition, the effect of 1BnTIQ on locomotor activity and dopamine release in vivo was also estimated in rat STR. In a behavioral study, acute administration of 1BnTIQ (50 mg/kg i.p.) produced a significant decrease in exploratory locomotor activity. A high-performance liquid chromatography with electrochemical detection ex vivo study showed that a single injection of 1BnTIQ produced a dramatic fall in the dopamine concentration in the noted brain regions (~65%; P < 0.01), but not in striatal serotonin. Moreover, 1BnTIQ reduced the content of the extraneuronal dopamine metabolite 3-MT by 70% (P < 0.01). Conversely, levels of DOPAC, HVA, and 5-HIAA were elevated by 220, 320, and 185%, respectively (P < 0.01). Interestingly, multiple 1BnTIQ treatments (50 mg/kg/day i.p. × 10 days) resulted in development of tolerance to its dopamine depressing effect, while the impairment of dopamine synthesis was persisted. An in vivo microdialysis study demonstrated that 1BnTIQ (50 mg/kg i.p.) produced a profound and long-lasting decrease in extraneuronal striatal dopamine. Concurrently, however, DOPAC and HVA were elevated. This comparison between ex vivo and in vivo effects of 1BnTIQ provides greater insight into the neurotoxic actions of 1BnTIQ specific to dopamine neurons. 1BnTIQ neurotoxicity may be related to an impairment of dopamine storage, leading to a fall in intraneuronal dopamine and enhanced dopamine catabolism through a monoamine oxidize-dependent oxidative pathway that results in free radical production and ultimate cell death. Because 1BnTIQ is an endogenous compound, it may be one of the factors responsible for idiopathic Parkinson’s disease.     

The antiepileptic primidone impairs male rat sexual behavior

Many antiepileptic drugs (AEDs) produce sexual impairments. Of commonly prescribed AEDs, primidone produces the greatest impairments. Here we examined the effects of primidone on male rat sexual behavior. Sexually-experienced male rats received administration of either vehicle or primidone. After baseline measures were obtained, the effects of daily primidone treatment on home cage sexual performance were assessed three times over the course of 14 days. Motor activity and sucrose preference were also assessed during this time period. Results indicate that primidone impaired copulation but not sexual motivation. Specifically, animals receiving primidone displayed fewer ejaculations, required more time to achieve an intromission, and displayed fewer intromissions per attempted mount as evidenced by a lower intromission ratio. However, animals treated with primidone also chose a goal box containing a sexually-receptive female in an x-maze as often as animals receiving vehicle. The lower intromission ratio suggests an inability to achieve intromissions perhaps as a result of impaired erectile function. Primidone did not affect motor activity or sucrose consumption, an additional measure of natural reward. Together, these data indicate that primidone impairs male sexual activity and suggest that these impairments result primarily from changes in erectile function and not changes to mechanisms mediating motivation.     

The impact of early environmental rearing condition on the discriminative stimulus effects and Fos expression induced by cocaine in adult male and female rats

Rationale  A number of environmental manipulations, including maternal separation (MS), have been shown to alter behavioral responses to drugs of abuse. Objectives  This study assessed if MS affected the stimulus and Fos-inducing effects of cocaine. Materials and methods  In experiment 1, male and female Sprague–Dawley rats were exposed to brief maternal separations (BMS), long maternal separations (LMS), or animal facility rearing (AFR) and then trained as adults to discriminate cocaine (10 mg/kg, intraperitoneally) from saline. Following training, generalization tests to novel doses of cocaine and other dopaminergic compounds were performed. Assessments of variations in training dose pretreatment times were also made. In experiment 2, male and female rats exposed to MS conditions were administered cocaine or saline for 14 days, and Fos expression in the mesolimbic system was measured. Results  In males, BMS retarded the acquisition of the cocaine discrimination. Generalization to novel doses of cocaine did not differ among rearing conditions, but the training dose cue lasted longer in LMS. Distinct generalization and ED₅₀ profiles were found between male rearing conditions for all dopamine compounds. While BMS females had higher cocaine ED₅₀ estimates, no other differences were found in females. LMS males and females, as well as AFR females, had significant increases in Fos expression after cocaine in a region-specific manner. No differences were found with other rearing groups. Conclusion  Early environmental variables altered the stimulus effects (in a sex-dependent manner) as well as the neuronal responsiveness to cocaine, which may be mediated by the dopamine system.