The effects of anticholinergics on the photopalpebral reflex, memory and mood

This study investigated central anticholinergic drug effects on: (1) the Randt Memory Test, a relatively new instrument which measures the acquisition and recall of verbal and pictorial information; (2) the averaged photopalpebral reflex (PPR), an electrophysiological parameter, the validity of which needs to be further investigated in pharmacological research and; (3) mood as measured by a 16-item visual analogue scale. Atropine (1 mg and 2 mg), pirenzepine (20 mg) and a placebo were administered intramuscularly in a double-blind cross-over trial in eight healthy volunteers. There were no inter-treatment differences on the Randt Memory Test. This finding is seemingly in contrast to those reported by some authors using other memory tests. In contrast to the reported effects of some benzodiazepines, the anticholinergics used in the present study did not prolong the latencies of the PPR, but reduced the amplitudes. Visual analogue scales indicated central effects for both pirenzepine and atropine. This implies pirenzepine's penetration of the blood-brain barrier and a physiological function for central muscarinic-1-receptors. The significant anticholinergic effects were exclusive to the "alertness" factor.     

Formulation of Vaccine Adjuvant Muramyldipeptides (MDP). 1. Characterization of Amorphous and Crystalline Forms of a Muramyldipeptide Analogue

A relatively nonhygroscopic crystalline form of the glycopeptide, N-acetylmuramyl-L--aminobu-tyryl-D-isoglutamine (I), containing approximately one molecule of water was prepared from amorphous material. The crystalline material, consisting of a mixture of the and anomers, exhibited better physical and chemical stability than the lyophilized amorphous material. The /-anomer ratios of I in both the crystalline and the amorphous state were approximately equal but different from that in solution.     

Advertising and the dental profession. Retrospective and prospective.

"Advertising" has become a very controversial topic, not just among dentists, but among all professionals. That controversy focuses on three questions. First, what are the legal issues surrounding dental advertising and how are these issues being resolved? Second, what are the attitudes toward advertising among practicing dentists and how are these attitudes changing? Finally, how many dentists advertise and what are those advertising dentists actually doing? The purpose of this paper is to neither praise nor excoriate advertising, but to refer to the law and to published research in order to provide dental practitioners with a broader understanding of this topic.     

The respiratory effects of drugs used for conscious sedation and general anesthesia

This review article illustrates that all medications used for conscious sedation can depress ventilation. The dental practitioner should not abandon the use of these agents to control fear and anxiety during dental treatment; rather, the dentist should administer the agents cautiously and monitor respiratory status throughout the dental procedure. In this regard, pulse oximetry is a welcomed advance in monitoring as it acts to warn the unknowing clinician that he is approaching a "cliff" (the steep portion of the oxyhemoglobin curve).     

Asthma deaths during sports: report of a 7-year experience

BACKGROUND: Asthma mortality and the mortality of athletes during sports have been described separately in detail in the medical literature. However, asthma has not been reported as a cause of death in competitive athletes. OBJECTIVE: The object of this study was to raise the awareness of physicians, coaches, trainers, and parents that children and adults can have fatal asthma exacerbations during and immediately after participating in sports. METHODS: The Temple Sports Asthma Research Center identified athletes from 1993 until 2000 who died during or after sporting activity by using the nationwide Burrell's Information Service. Once a possible asthma-related sports death was identified, the autopsy report was requested from the coroner or medical examiner, and an attempt was made to contact the family. Contact with the family was limited to information about the death, medical history, sports involvement, and any medication usage by the person who had died. Secondary sources, including news reports, were used to confirm whether the subject died of asthma during or immediately after a sporting activity. RESULTS: Two hundred sixty-three possible cases were identified. Sixty-one deaths met the criteria for study inclusion. White deaths outnumbered black deaths by 2 to 1. Deaths among male subjects predominated. Most subjects were younger than the age of 20 years, with the most prevalent age group being between 10 to 14 years old. Fifty-one percent (18 of 35) of the competitive athletes had their fatal event while participating in organized sport, 14 in a practice situation and 4 deaths during a game or meet setting. Basketball and track were the 2 most frequent activities performed at the time of the fatal event. CONCLUSION: The subjects who had fatal asthma exacerbations were usually white male subjects between the ages of 10 and 20 years. Mild intermittent or persistent asthma by history was commonly identified. Sudden fatal asthma exacerbations occur in both competitive and recreational athletes and can be precipitated by sporting activity.     

Regulatory effects of biophysical strain on rat TMJ discs

Recent studies have revealed that dynamic biomechanical forces can exert antiinflammatory and antiproteolytic effects on fibrocartitage. Whether the effects of mechanical strain also involve stimulation of the insulin-like growth factor (IGF) system and, therefore, of growth and repair of fibrocartilage has yet to be determined. The objective of this in vitro study was to determine if continuous biophysical strain regulates the gene expression of IGF1, IGF2, IGF1 receptor (IGF1R), insulin receptor substrate (IRS1), and IGF-binding proteins (IGFBP) 3 and 5 in cells from the fibrocartilaginous disc of the temporomandibular joint (TMJ). Rat TMJ disc cells were subjected to continuous biophysical strain (3% and 20%) for 4 and 24 h. Subsequently, RNA was extracted and real-time PCR was performed using an iCycler iQ detection system to analyze the gene expression of the IGF system. The gene expression of IGF1, IGF2, IGF1R, IRS1, IGFBP3, and IGFBP5 was significantly (p < 0.05) inhibited when cells were subjected to continuous biophysical strain, as compared to control at both time points. High strain induced a stronger inhibition of these molecules as compared to strain of Low magnitude. In conclusion, continuous biophysical strain seems to downregulate the expression of the IGF system and may, therefore, reduce the potential of fibrocartilage for growth and repair.     

Complement-opsonized HIV: the free rider on its way to infection

The complement system (C) is one of the main humoral components of innate immunity. Three major tasks of C against invading pathogens are: (i) lysis of pathogens by the formation of the membrane attack complex (MAC); (ii) opsonization of pathogens with complement fragments to favor phagocytosis; and (iii) attraction of inflammatory cells by chemotaxis. Like other particles, HIV activates C and becomes opsonized. To escape complement-mediated lysis, HIV has adopted various properties, which include the acquisition of HIV-associated molecules (HAMs) belonging to the family of complement regulators, such as CD46, CD55, CD59, and the interaction with humoral regulatory factors like factor H (fH). Opsonized virus may bind to complement receptor positive cells to infect them more efficiently or to remain bound on the surface of such cells. In the latter case HIV can be transmitted to cells susceptible for infection. This review discusses several aspects of C-HIV interactions and provides a model for the dynamics of this process.     

The influence of surface roughness of titanium on beta1- and beta3-integrin adhesion and the organization of fibronectin in human osteoblastic cells

Mechanisms of cell adhesion and extracellular matrix formation are primary processes in the interaction with the material surface of an implant which are controlled by integrin receptors. The aim of our study was to find out whether beta1- and beta3-integrins of osteoblastic cells sense the surface topography of titanium, and if structural alterations of integrin adhesions were involved in the organization of fibronectin. Pure titanium surfaces were modified by polishing (P), machining (NT), blasting with glass spheres (GB), and blasting with corundum particles (CB) resulting in increasing roughness. Confocal microscopic investigations revealed fibrillar adhesions of beta1- and alpha5-integrins on P, NT, and GB, but on CB with its sharp edges these integrin subunits did not form fibrillar adhesions. beta3 generally appeared in focal adhesions. We observed aligned fibrillar structures of fibronectin on NT not only on the basal site but interestingly, also on the apical cell surface. In contrast, on CB, fibronectin appeared apically clustered. We suggest that this alignment of fibronectin fibrils depends on the directed actin cytoskeleton and in particular, on the capability of the beta1-integrins to form fibrillar adhesions, which is affected by the surface roughness of titanium.     

Ultrastructural alterations during ATP-induced secretion of lysosomal enzymes from rabbit polymorphonuclear leukocytes

Rabbit neutrophils incubated in low-ionic-strength media were stimulated by ATP to secrete lysosomal enzymes. This was greatly enhanced in the presence of cytochalasin B. ATP in these circumstances induced the cell to form large cytoplasmic extensions that were largely devoid of granules. In the presence of both ATP and cytochalasin B, however, the projections contained granules in close proximity to the cell membrane. Neutrophils in low-ionic-strength buffer were capable of binding to zymosan particles coated with C3b but not of phagocytizing them. Release of granule enzymes was observed and exocytosis of granules appeared to occur at sites distant from those portions of the plasma membrane adherent to the particle.Support was provided by U.S.P.H.S. grant A1-07007 and GMS 19322-03 and by U.S.P.H.S. Career Development Award 1-KO4GM-42567-05 to Dr. P.M. Henson. This is publication no. 873 from the Department of Immunopathology, Scripps Clinic and Research Foundation, La Jolla, California.Support was provided by U.S.P.H.S. grant A1-09648.