Idiopathic lumbosacral plexus neuropathy in child. Case report

We describe a lumbosacral plexus neuropathy case in childhood in which detailed investigation, including electromyography and magnetic resonance imaging, was normal. Muscle biopsy showed mild denervation. No underlying condition was detected. The patient presented with pain, weakness and light atrophy in left lower limb, reduced reflex at the ankle, loss of the quadriceps reflex and paresthesy in involved limb. Recovery after one year was almost complete, with persistent slight weakness and atrophy.     

Atropine inhibits gastric distension and pharyngeal receptor mediated lower oesophageal sphincter relaxation

Although a limited number of drugs make up the mainstay of treatment of endometriosis, many alternative medications have been used in an attempt to improve efficacy. Some have been rigorously evaluated and are of proven benefit, while others show promise in preliminary trials or in animal models. Proper methods of evaluating medical therapy and outcomes are essential. This chapter provides a review of new medical therapies for the treatment of endometriosis and their evaluation.     

Bladder PDT with intravesical clear and light scattering media: effect of an eccentric isotropic light source on the light distribution

To optimize the performance of off-road bicycle suspension systems, a dynamic model of the bicycle/rider system would be useful. This paper takes a major step toward this goal by developing a dynamic system model of the cyclist. To develop the cyclist model, a series of four vibrational tests utilizing random inputs was conducted on seven experienced off-road cyclists. This allowed the transfer functions for the arms and legs to be determined. To reproduce the essential features (i.e., resonance peaks) of the experimental transfer functions, the system model included elements representing the visceral mass along with the arms and legs. Through simulations, the frequency responses of the system model of the rider in each of the four tests were computed. Optimal stiffness and damping parameter values for each subject were determined by minimizing the difference between the experimental and simulation results. Good agreement between experimental and simulation results indicates that modeling the rider as a lumped parameter system with linear springs and dampers is possible.     

Infections and vasculitis]

Recent interest in case management by elementary and secondary schools has arisen out of a growing recognition that schools alone are not prepared to address the myriad of health, education, and social service needs of a large number of students, particularly children living in poverty. Boys and girls entering classrooms hungry, sick, homeless, or otherwise distracted are not ready to learn. Improving readiness to learn is a major agenda among educators. Case management is one approach many schools are beginning to use to collaboratively engage parents, community service agencies, the private sector, and communities at large in pursuit of the goal. A promising school-based case management model has been developed and successfully field tested by the University of Washington. The model operationally defines case management, delineates a delivery structure, and includes an evaluation design. Results from a five-year study sponsored by the U. S. Department of Education are encouraging. Although several challenges persist, the future for school case management use is optimistic. Several enhanced variations of the Center for the Study and Teaching of At-Risk Students (C-STARS) case management model are now being demonstrated across the country.     

Treatment of posttraumatic stress disorder with nefazodone

Selective serotonin reuptake inhibitors are useful in the treatment of posttraumatic stress disorder (PTSD), but have a number of side-effects which limit their acceptability. A newer serotonergic compound, nefazodone, has a different side-effect profile, thus making it a potentially promising compound to study. Seventeen private practice patients with PTSD were treated with nefazodone up to 600 mg/day for a maximum total treatment period of 12 weeks. All subjects were civilians, and were monitored for efficacy and side-effects at weeks 1, 2, 4, 6, 8 and 12. Nefazodone was associated with statistically significant improvement in mean scores on all six rating scales used to assess change from baseline in PTSD symptoms. Additionally, statistically significant improvement from baseline were seen for the intrusive, avoidant/numbing, and hyperarousal clusters on a global PTSD scale. Early improvements in nightmares and general sleep disturbance were observed. Overall, there was a 43% response rate at endpoint, or 60% in treatment completers, by observer rating. Side-effects (assessed on the Medication Effects Scale) were generally benign. Nefazodone was associated with clinical improvement in this population, and now needs to be studied in double-blind, placebo controlled, protocols.     

Mechanism for the enzymatic formation of 4-(beta-D-ribofuranosyl)aminobenzene 5'-phosphate during the biosynthesis of methanopterin

A central step in the biosynthesis of the modified folate methanopterin is the condensation of p-aminobenzoic acid (pAB) and 5-phospho-alpha-D-ribosyl-1-pyrophosphate (PRPP) which produce 4-(beta-D-ribofuranosyl)aminobenzene 5'-phosphate (beta-RFA-P) [White, R. H. (1996) Biochemistry 35, 3447-3456]. This reaction, catalyzed by the enzyme beta-RFA-P synthase, is unique among known phosphoribosyltransferases in that a decarboxylation of one of the substrates (pAB) occurs during the reaction and a C-riboside rather than an N-riboside is the product. In this work, the reaction catalyzed by the enzyme from Methanosarcina thermophila is shown to be analogous to other phosphoribosyltransferase reactions in that pyrophosphate is released as a product of the reaction, which is dependent upon magnesium ions. The molecular weight of the enzyme was estimated to be 65 000 using gel filtration chromatography, and the pH optimum was 4.8. Kinetic analysis indicated that the reaction involved a sequential pattern of substrate binding. Benzoic acid and several para-substituted benzoic acids inhibited beta-RFA-P synthase activity, while aniline, 4-aminobenzamide, and the methyl ester of pAB did not, indicating that an ionized carboxylic group plays a role in the binding of pAB. The observation that the enzyme was not inhibited by carbonyl reagents and that 4-hydroxybenzoic acid served as an alternate substrate, producing 4-(beta-D-ribofuranosyl)hydroxybenzene 5'-phosphate as the product, indicated that pyridoxal phosphate was not directly involved in the reaction mechanism. Incubation of the enzyme with PRPP and either pAB or 4-aminothiobenzoic acid in the presence of sodium cyanoborohydride led to the decreased production of beta-RFA-P and the accumulation of a reduced form of the proposed cyclohexadienimine reaction intermediates. These compounds were characterized by their acid-catalyzed decomposition which produces beta-D-ribofuranosylbenzene 5'-phosphate. On the basis of these results, a concerted mechanism is proposed for beta-RFA-P synthase in which an SN1-like reaction produces oxonium ion character at C-1 of PRPP which undergoes an ipso electrophilic aromatic substitution reaction at the carboxylic acid-bound carbon of pAB. Decarboxylation of the resulting cyclohexadienimine intermediate leads to the formation of beta-RFA-P.     

Effects of very low dose and enteric-coated acetylsalicylic acid on prostacyclin and thromboxane formation and on bleeding time in healthy subjects

OBJECTIVE: Low dose acetylsalicylic acid (ASA) is widely used as an anti-aggregatory agent in the primary and secondary prevention of cardiovascular diseases. In an effort to spare prostacyclin formation and to reduce gastrointestinal side-effects, both very low doses and enteric-coated formulations of ASA have been introduced. However, it still remains unclear whether these different formulations and dosages are equally effective with respect to inhibition of platelet aggregation and thromboxane A2 (TXA2) formation. METHODS: In a randomized study, we therefore investigated the effects of 100 mg ASA plain (p), 100 mg ASA enteric-coated (ec) and 40 mg ASA (p) to 36 healthy male subjects given for 7 days on platelet aggregation and endogenous prostanoid formation rates. Platelet aggregation and platelet TXB2 release in platelet rich plasma (PRP) and serum TXB2 and 6-keto-PGF1alpha levels were determined at baseline and after 7 days of each medication. The urinary metabolites of TXA2 (2,3-dinor-TXB2) and prostacyclin (2,3-dinor-6-keto-PGF1alpha) were measured by gas chromatography/tandem mass spectrometry in 24-h-urines at baseline and on day 7 of each medication. RESULTS: Collagen-induced platelet aggregation was 73.1+/-1.6% of maximal aggregation at baseline. It was inhibited by 68.9%, 58.6% and 24.0% by ASA 100 mg plain, 100 mg enteric-coated, and 40 mg plain on day 7, respectively. Platelet TXB2 release was 11592.0+/-367.5 pg x ml(-1) PRP. It was inhibited by 90.1%, 86.5%, and 55.2% by ASA 100 mg plain, 100 mg enteric-coated, and 40 mg plain, respectively. Serum TXB2 was almost completely reduced on day 7 by 100 mg ASA, but not by 40 mg ASA; serum 6-keto-PGF1alpha was slightly, but significantly reduced in all three groups. Urinary 2,3-dinor-TXB, excretion was 196.0+/-41.5 pg x mg(-1) creatinine at baseline. It was reduced by 80.3% and 79.1% by ASA 100 mg plain and enteric-coated, respectively (each P < 0.05 versus baseline), but only by 55.4% by ASA 40 mg plain (P < 0.05 versus both formulations of ASA 100 mg). CONCLUSIONS: Our present data show that the plain and enteric-coated formulations of 100 mg ASA are equally effective in inhibiting platelet aggregation, platelet thromboxane production, and urinary 2,3-dinor-TXB2 excretion rates. In contrast, a very low dose of 40 mg ASA was significantly less effective in inhibiting these indices of platelet activation in healthy human subjects. ASA enteric-coated 100 mg may be a useful alternative to 100 mg ASA (p) in patients with gastrointestinal side-effects, whereas 40 mg ASA (p) may be too low to inhibit sufficiently platelet activity in patients with cardiovascular diseases in whom platelet activity is increased.