Physiological analysis of motor reorganization following lower limb amputation.

It is now known that amputation results in reorganization of central motor pathways, but the mechanism for the changes is unclear. One possibility is alteration of the excitability of the alpha motoneurons. We studied motor reorganization and excitability of alpha motoneurons to Ia input in 6 subjects with unilateral lower limb amputation. A Cadwell MES-10 stimulator was used to deliver transcranial magnetic stimuli through a circular coil centered on the sagittal axis 4 cm anterior to Cz and through an 8-shaped coil positioned over scalp locations 1 cm apart along the coronal axis. Surface EMG was recorded bilaterally from quadriceps femoris, the first muscle immediately proximal to the site of amputation. Excitability of the spinal alpha motoneuron pool to Ia afferents was assessed by determining the ratio of the maximal H reflex to the maximal M response (H/M ratio) elicited in the quadriceps femoris. Stimuli of equal intensity delivered to optimal scalp positions recruited a larger percentage of the alpha motoneuron pool in muscles ipsilateral to the stump than in those contralateral to the stump (P less than 0.01). Mean onset latencies of motor evoked potentials were shorter in ipsilateral muscles than in contralateral muscles (P less than 0.01). Muscles ipsilateral to the stump showed a trend toward activation from a larger number of scalp positions than those contralateral to the stump (P = 0.06). There was no difference in the quadriceps H/M ratios (7.2% ipsilateral vs. 10.9% contralateral). The absence of changes in the excitability of the alpha motoneuron pool in the presence of motor reorganization targeting muscles proximal to the stump suggests that reorganization occurs proximal to the alpha motoneuron level.     

Physiological abnormalities in hereditary hyperekplexia.

Five patients from a kindred with hereditary hyperekplexia had physiological testing. The surface-recorded electromyographic pattern of audiogenic muscle jerks was identical to that of the normal acoustic startle reflex. Testing at graded stimulus intensities indicated an increase in the gain of the acoustic startle reflex. Nose-tap stimuli resulted in short-latency generalized electromyographic bursts that were similar to the R1 component of the blink reflex. Electrical stimulation of peripheral nerves elicited a pattern of generalized muscle jerks that was similar to that of the acoustic startle reflex. Somatosensory evoked potentials, brainstem auditory evoked potentials, and cortical auditory evoked potentials were normal. The primary physiological abnormality in hereditary hyperekplexia is widespread elevated gain of vestigial withdrawal reflexes in the brainstem and possibly the spinal cord, most likely resulting from increased excitability of reticular neurons.     

Effect of pretreatment with the selective β1-adrenoceptor antagonist bisoprolol on the subsequent cardiovascular actions and β-adrenoceptor subtype specific occupancy of celiprolol in healthy man

Summary The cardiovascular effects at rest and during exercise and ₁- and ₂-adrenoceptor occupancy following a single dose of 1200 mg celiprolol p. o. were investigated in 8 healthy subjects with or without pretreatment with a single dose of 20 mg bisoprolol p. o., using a place-bo-controlled, 2-way cross-over design.The ergometric responses of heart rate (HR) and systolic blood pressure (SBP) after celiprolol were reduced to a similar extent as after bisoprolol, but the cardiovascular function at rest was affected in a different way: there was a rise in HR, clear enhancement of cardiac systolic performance, and a considerable drop in the estimated total peripheral vascular resistance, associated with median ₁-RRA and ₂-RRA occupancies of 88 and 34%, respectively. The cardiovascular effects of celiprolol were not affected by pretreatment with bisoprolol. Celiprolol thus binds extensively to ₁-adrenoceptors, moderately to ₂-adrenoceptors, acts as ₁-adrenergic antagonist (exemplified by the ergometric effects) but has vasodilator, positive chronotropic and cardiac systolic performance enhancing properties, which do not involve either direct or indirect ₁-adrenergic agonism, but which might reflect ₂-adrenergic agonism.     

Effectiveness of psychological interventions to reduce alcohol consumption among pregnant and postpartum women: a systematic review

Archives of Women's Mental Health - This study aims to synthesise the available evidence on psychological interventions to reduce alcohol consumption among pregnant and postpartum women. Six...     

Inhibitory potency of quinolone antibacterial agents against cytochrome P450IA2 activity in vivo and in vitro.

Inhibition of cytochrome P450IA2 activity is an important adverse effect of quinolone antibacterial agents. It results in a prolonged half-life for some drugs that are coadministered with quinolones, such as theophylline. The objective of the study described here was to define the parameters for quantifying the inhibitory potencies of quinolones against cytochrome P450IA2 in vivo and in vitro and to investigate the relationship between the results of both approaches. Cytochrome P450IA2 activity in vitro was measured by using the 3-demethylation rate of caffeine (500 microM) in human liver microsomes. The inhibitory potency of a quinolone in vitro was determined by calculating the decrease in the activity of cytochrome P450IA2 caused by addition of the quinolone (500 microM) into the incubation medium. The mean values (percent reduction of activity without quinolone) were as follows: enoxacin, 74.9%; ciprofloxacin, 70.4%; nalidixic acid, 66.6%; pipemidic acid, 59.3%; norfloxacin, 55.7%; lomefloxacin, 23.4%; pefloxacin, 22.0%; amifloxacin, 21.4%; difloxacin, 21.3%; ofloxacin, 11.8%; temafloxacin, 10.0%; fleroxacin, no effect. The inhibitory potency of a quinolone in vivo was defined by a dose- and bioavailability-normalized parameter calculated from changes of the elimination half-life of theophylline and/or caffeine reported in previously published studies. Taking the pharmacokinetics of the quinolones into account, it was possible to differentiate between substances with and without clinically relevant inhibitory effects by using results of in vitro investigations. The in vitro test described here may help to qualitatively predict the relevant drug interactions between quinolones and methylxanthines that occur during therapy.     

The Health and Economic Effects of Counterfeit Drugs

Background

Counterfeit drugs comprise an increasing percentage of the US drug market and even a larger percentage in less developed countries. Counterfeit drugs involve both lifesaving and lifestyle drugs.

Objective

To review the health and economic consequences of counterfeit drugs on the US public and on the healthcare system as a whole.

Method

This comprehensive review of the literature encompassed a search of MEDLINE/PubMed, Google Scholar, and ProQuest using the keywords “counterfeit drugs,” “counterfeit medicines,” “fake drugs,” and “fake medicines.” A search of the various FiercePharma daily newsletter series on the healthcare market was also conducted. In addition, the US Food and Drug Administration and the World Health Organization websites were reviewed for additional information.

Discussion

The issue of counterfeit drugs has been growing in importance in the United States, with the supply of these counterfeit drugs coming from all over the world. Innovation is important to economic growth and US competitiveness in the global marketplace, and intellectual property protections provide the ability for society to prosper from innovation. Especially important in terms of innovation in healthcare are the pharmaceutical and biopharmaceutical industries. In addition to taking income from consumers and drug companies, counterfeit drugs also pose health hazards to patients, including death. The case of bevacizumab (Avastin) is presented as one recent example. Internet pharmacies, which are often the source of counterfeit drugs, often falsely portray themselves as Canadian, to enhance their consumer acceptance. Adding to the problems are drug shortages, which facilitate access for counterfeits. A long and convoluted supply chain also facilitates counterfeits. In addition, the wholesale market involving numerous firms is a convenient target for counterfeit drugs. Trafficking in counterfeits can be extremely profitable; detection of counterfeits is difficult, and the penalties are modest.

Conclusion

Counterfeit drugs pose a public health hazard, waste consumer income, and reduce the incentive to engage in research and development and innovation. Stronger state licensure supervision of drug suppliers would be helpful. Technological approaches, such as the Radio Frequency Identification devices, should also be considered. Finally, counterfeit drugs may raise concerns among consumers about safety and reduce patient medication adherence.Intellectual property represents original, creative works and innovations who belonging to inventors, artists, musicians, and authors who, and businesses that, create something or acquire rights to a creation. The exclusive rights and legal protections of intellectual property come in the form of copyrights, trademarks, and patents. These protections encourage innovation and creativity, but the rewards for innovation and creativity can be undermined by widespread theft associated with counterfeiting and trafficking of pirated goods. The Internet has become an important and convenient means for consumers to shop and save money. However, websites that traffic counterfeit goods have flourished on the Internet, creating confusion between which sites sell authentic goods and which do not.When reflecting on counterfeit and pirated goods, knockoff luxury handbags, fake watches, and free music and videos may come to mind. The counterfeiting and pirating of goods may seem to be a victimless crime, where no one is harmed by imitation goods sold at much lower prices than brand-name products. However, the world of counterfeiting and piracy stretches to nearly every product on the market and has often led to considerable harm to consumers, including death. The consequences are well-known, as the Department of Homeland Security states, “counterfeit and pirated goods pose a serious threat to America''s economic vitality, the health and safety of American consumers, and our critical infrastructure and national security.”1 Piracy and counterfeiting are not victimless crimes; they cost US businesses more than $200 billion annually and account for the loss of more than 750,000 jobs.2 This is also a worldwide problem.Medicines have often been counterfeited, sometimes with dire consequences to patients.3 Counterfeit drugs are a public health issue in the United States and worldwide. The issue of counterfeit drugs has been growing in the United States with the supply of these counterfeit drugs coming from all over the world. Counterfeit drugs not only take income from consumers, by having them pay for products that have little or no medical value, but they can also lead to unresolved health problems, and even death.3 There are various issues involved with counterfeit drugs and reducing their availability. Especially significant, counterfeit drugs may raise concerns among consumers about safety, and may therefore reduce patient adherence.In this review, we examine how the legitimate supply chain has been infiltrated by counterfeits, as well as the role of the Internet in facilitating the distribution of counterfeit drugs, and the impact on patients, drug innovation, and the pharmaceutical industry.