The influence of therapy (sympathomimetic amines versus vasodilators) in the indexes of ejection fraction derived from an analysis of Doppler aortic flow

The purpose of this study was to map the distribution of alpha-subunits of G-proteins--Galpha(olf s), Galpha(olf), Galpha(s), Galpha(i), Galpha(o), Galpha(z) and Galpha(q11)--in developing, denervated or injured rat molar teeth, using fluorescence microscopic immunohistochemistry coupled with immunogold electron microscopic immunocytochemistry. In rat fetuses (E17-E21), a widespread expression of Galpha(q11) was seen in maxillary/mandibular mesenchyme as well as in developing teeth. In addition, intensely Galpha(o)-positive nerve fibers were associated with the dental epithelium and the dental papilla of developing teeth. Other G proteins were absent or sparsely distributed during early tooth development. In the adult tooth pulp, odontoblasts appeared to express mainly Galpha(olf s), Galpha(o), and Galpha(q11). Nerve fibers were immunoreactive to Galpha(i), Galpha(o) and Galpha(z). In addition, pulpal blood vessels expressed varying levels of Galpha(olf s) Galpha(z) and Galpha(q11) while Galpha(olf s), Galpha(olf), Galpha(o) and Galpha(q11) were found in various pulpal mesenchymal cells. After adult denervation, nerve fiber-related G-protein immunoreactivity disappeared, but no other changes in pulpal G-protein immunoreactivity were noted. Odontoblasts and mesenchyme cells were intensely Galpha(i)-positive underneath a pulpal traumatic exposure, indicating an injury-induced pulpal upregulation of Galpha(i). The findings that Galpha(i), Galpha(o) and Galpha(z) are expressed in pulpal sensory nerve fibers suggest that these G proteins participate in signal conveyance from the target to the trigeminal nerve cell body.     

Estimating ancestral states of a communicative display: a comparative study of Cyclura rock iguanas

In this study we describe the signature headbob displays of seven of the eight extant species of Cyclura iguanas using data collected from the field and from captive animals. We used phylogenetic comparative methods to estimate the ancestral states of several measures of the headbob displays, including number of headbobs and the duration of headbobs and inter-bob pauses. Divergence in the headbob display among species has been substantial, with some major changes occurring within only a few (about six) generations. Otherwise, results are consistent with those obtained previously for other lizards which suggest that there is an evolutionary limit on the total duration of headbob displays. Differences in the results obtained using different phylogenetic methods suggest that although estimates of ancestral states are reasonably robust to violations of evolutionary assumptions, we cannot determine the standard errors of those ancestral phenotypes accurately without more detailed information about the types of forces (e.g. selection, drift) underlying evolutionary change in these traits. In particular, within-species variation had a substantial impact on the standard errors of estimated ancestral states, and should be included in such estimations whenever possible. Finally, our results emphasize the importance of conserving behavioural as well as genetic diversity in trying to preserve endangered species for possible reintroduction into the wild. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.     

Airway responses to capsaicin in guinea pigs: role of NK-1 and NK-2 neurokinin receptors

The role of NK-1 and NK-2 receptors on the pulmonary response to capsaicin in guinea pigs was evaluated using intravenous infusion of selective nonpeptide antagonists of NK 1 (CP 96345, 300 nmol/kg, and SR 140333, 300 nmol/kg) and NK-2 (SR 48968, 100 nmol/kg) neurokinin receptors. Maximal values of pulmonary dynamic elastance (Edyn) and pulmonary resistance (RL) after capsaicin infusion were significantly lower in the presence of SR 48968 (p < .005). Morphometric analysis of lungs obtained by quick-freezing showed significant attenuation of airway contraction and peribronchiolar edema formation in the presence of NK-2 antagonist (p < .001). When compared to guinea pigs that received only capsaicin, animals that received SR 140333 or CP 96345 showed lower values of Edyn, RL, airway contraction, and peribronchiolar edema, but only the difference in Edyn values was significant. The combination of NK-1 and NK-2 antagonists was not more effective than NK-2 antagonist alone in attenuating capsaicin effects. The results suggest that airway effects of capsaicin are mainly mediated by activation of NK-2 receptors although NK-1 receptors may also play a role.     

Optimal detection of weak nJ(1H- 119Sn) couplings by gradient-enhanced 1D and 2D heteronuclear multiple-quantum correlation spectroscopy. Application to a novel tin derivative of erythromycin A

A study was carried out to determine the distribution of cockroaches in two different housing areas with central sewerage or individual septic tanks in an urban area in Kuala Lumpur, Malaysia. Six species of cockroaches were present and of these Periplaneta americana and Periplaneta brunnea were found in greater abundance. Seventeen species of bacteria were isolated and of these Escherichia coli and Klebsiella p. pneumoniae were isolated in greatest numbers. Control measures carried out using lambda cyhalothrin showed that there was no significant difference between treated and control sites.     

Nevoid basal-cell syndrome: literature review and case report in a family

The Nevoid Basal-Cell Carcinoma Syndrome (NBCC), or as it is also referred to, basal-cell nevus syndrome or Gorlin-Goltz syndrome, is characterized by multiple early-appearing basal cell carcinomas, keratocytosis of the mandible, and anomalies of the ocular, skeletal reproductive system. We describe four patients in the same family, all of them possessing a large number of skin tumors associated with other typical clinical and X-Ray anomalies of NBCC. The definitive treatment of NBCC has yet to be established, however, early diagnosis is very important as well as the periodical follow-up examination of ten patients, mainly due to the transformations in the skin lesions that may occur.     

Buck quasi-resonant converter operating at constant frequency:analysis, design, and experimentation

A buck pulsewidth modulated zero-current switching quasi-resonant converter (buck PWM ZCS QRC) operating at constant frequency is discussed. Operating principle and design-oriented analysis are presented with normalized design curves, design procedure, design example, simulations, and experimental results. The new topology, which can be considered as a particular one, is compared with the well-established buck frequency-modulated zero-current switching quasi-resonant converter (buck FM ZCS QRC) proposed by Fred C. Lee (1988)     

Mixed real/complex factorization [power systems]

A mixed real/complex sparse matrix factorization and solution scheme applied to a large matrix problem is described. Large system eigenanalysis and frequency domain methods will directly benefit from the proposed scheme, which can reduce both memory and CPU time requirements when compared to conventional complex-only solutions. The application in hand is the small signal electromechanical stability analysis of large power systems. The savings obtained are significant considering the CPU-intensive nature of these matrix problems     

Preventive administration of ornithine alpha-ketoglutarate improves intestinal mucosal repair after transient ischemia in rats

Introduction; Healthcare professionals need to continually update their knowledge to provide care based on scientific evidence. In some cases it can be difficult to gain access to the different sources of medical information. In an attempt to overcome these problems, a toll-free telephone medical information service (Doctorline) was established. OBJECTIVE: To describe the development, aims, organization, and activities of this private service. METHODS: Doctorline is an independent, unbiased, toll-free medical information service that provides information on clinical, pharmacologic, and toxicologic issues; bibliographic searches; full-text articles; public and private clinics; details of forthcoming congresses; and legislative documentation. The service is available Monday through Friday, 1000 to 2000. Staff members are physicians trained in communication techniques, literature evaluation methodologies, and computerized database use. The main on-line facilities are MEDLINE, Micromedex-CCIS, and the Italian Formulary on CD-ROM. Books, bulletins, national and international drug formularies, and property files (i.e., directory of Italian public and private clinics) are also available. RESULTS: In 5 years, Doctorline has received 65 258 calls. Nearly 34% of the calls were made by general practitioners, followed by cardiologists (22%), orthopedists (15%), pharmacists (14%), gastroenterologists (13%), and urologists (10%). From 1991 to 1996, nearly 20% of the calls concerned pharmacologic issues, 43% nonpharmacologic issues, while the rest of the calls were for nonclinical requests. Approximately 21% of all questions received an answer during the same phone call (on-line answers); for the other answers (off-line answers) the mean +/- SD waiting time was 7.8 +/- 10.4 days. Although the nature of the questions has been recorded since 1991, data about the exact number of physicians who used the service are available only from 1994. Data from 1994 indicate that of the 52,181 physicians who could access the service, only 8817 (16.9%) called at least once, with a mean number of calls per physician of 3.9 (range 3.0-5.6). CONCLUSIONS: The future of Doctorline will depend on the quality and validity of the information provided (i.e., based exclusively on scientific evidence, independent of the source of funds), the promotion of the aims, organization, and clinical utility of the service (especially among physicians who made little or no use of the service), and differentiation of the service activities in relation to the physician's specific needs.     

Second-order sensitivity analysis in vibration and buckling problems

A perturbation approach for the first- and second-order sensitivity analysis of eigenvalue problems, as they arise in buckling and vibration of structural systems, is presented. A particular feature introduced in the formulation is the dependence of all matrices that model the problem not only on the design parameter, but also on a pre-critical state. Thus, the sensitivity of the response of the fundamental path in buckling problems, or a pre-stressed state, in vibration problems, are introduced in the analysis. Two techniques are considered in this work: the direct and the adjoint methods. First- and second-order sensitivity equations for eigenvalues and eigenvectors are obtained, and it is shown that second-order sensitivity of an eigenvalue can be accomplished by using only one adjoint problem.