Extraction and quantification of epibatidine in plasma

Epibatidine was extracted from human and mouse plasma into a hexane-isopropanol mixture and back-extracted into a phosphate buffer, pH 2.5, then identified by HPLC isocratically using a CN column and quantified with ultraviolet detection at a fixed wavelength of 214 nm. The percent recovery of epibatidine from spiked plasma samples was 83.6% and the percent extraction was linear between 10 and 1,000 ng/ml. Desipramine was used as the internal standard. For spiked control samples containing 50 and 750 ng/ml, between-day precisions were 20.8 and 7.2% (RSD%), respectively; accuracy was 87.0 and 99.1%, respectively. The limit of detection was 2 ng/ml. Using this method, an intraperitoneal dose of 0.1 mg/kg of epibatidine produced mean levels of 7.3 and 37.1 ng/ml in pooled male and female plasma samples from C57BL/10 J mice, respectively. This is a simple and straightforward procedure by which plasma samples may be analyzed for epibatidine.

The effect of genotype on sensitivity to electroacupuncture analgesia

Individual differences in sensitivity to pain and analgesia are well appreciated, and increasing evidence has pointed towards a role of inherited genetic factors in explaining some proportion of such variability. It has long been known by practitioners of acupuncture, an ancient modality of analgesia, that some patients are 'responders' and others 'non-responders.' The present research was aimed at defining the inherited genetic influence on acupuncture analgesia in the mouse, using 10 common inbred strains. Two pairs of metallic needles were inserted into acupoints ST 36 and SP 6, fixed in situ and then connected to the output channel of an electric pulse generator. Electroacupuncture (EA) parameters were set as constant current output (intensity: 1.0-1.5-2.0 mA, 10 min each; frequency: 2 or 100 Hz) with alteration of a positive and negative square wave, 0.3 ms in pulse width. Tail-flick latencies evoked by radiant heat were measured before, during and after EA stimulation. Narrow-sense heritability estimates of 2 and 100 Hz EA were 0.37 and 0.16, respectively. We found that the C57BL/10 strain was the most sensitive, and the SM strain was the least sensitive to both 2 and 100 Hz EA. However, the relative sensitivities of other strains to these two EA frequencies suggested some genetic dissociation between them as well. These results demonstrate a role of inherited genetic factors in EA sensitivity in the mouse, although the low-to-moderate heritability estimates suggest that environmental factors may be of greater importance in predicting who will benefit from this analgesic modality.

Sex differences in thermal nociception and morphine antinociception in rodents depend on genotype

It has been appreciated for some time that the sexes can differ in their sensitivity to pain and its inhibition. Both the human and rodent literatures remain quite contentious, with many investigators failing to observe sex differences that others document clearly. Recent data from our laboratory have pointed to an interaction between sex and genotype in rodents, such that sex differences are observed in some strains but not others. However, these studies employed inbred mouse strains and are thus not directly relevant to existing data. We presently examined whether the observation of statistically significant sex differences in nociception and morphine antinociception might depend on the particular outbred rodent population chosen for study. Rats of both sexes and three common outbred strains were obtained from three suppliers (Long Evans, Simonsen; Sprague Dawley, Harlan; Wistar Kyoto, Taconic) and tested for nociceptive sensitivity on the 49 degrees C tail-withdrawal assay, and antinociception following morphine (1-10mg/kg, i.p.). In further studies, three outbred populations of mice (CD-1, Harlan; Swiss Webster, Harlan; Swiss Webster, Simonsen) were bred in our vivarium for several generations and tested for tail-withdrawal sensitivity and morphine antinociception (1-20male, and no significant difference. In a separate study in which the estrous cycle was tracked in female mice, we found evidence for an interaction between genotype and estrous phase relevant to morphine antinociception. However, estrous cyclicity did not explain the observed sex differences. These data are discussed with respect to the existing sex difference and pain literature, and also as they pertain to future investigations of these phenomena.

Hospital pharmacy service provision in Australia--1998

The results of a 1998 national survey of pharmaceutical services in hospitals throughout Australia are reported. A self-administered questionnaire was sent to all directors of hospital pharmacy services and senior hospital pharmacy managers to determine the extent of clinical and nonclinical pharmacy services provided by hospitals in Australia. Respondents chose the services their departments provide from a list of 26 commonly provided services. The response rate was 58.5%. Respondents were fairly evenly divided between teaching and nonteaching hospitals, but most of the respondents were from public (versus nongovernment) hospitals. The five most commonly provided services were imprest (a wordstock of frequently used medications that are regularly restocked by the pharmacy department), informal drug education for hospital staff, review of medication charts, control of drug purchasing, and inpatient dispensing. Review of medication charts and provision of drug education for the hospital staff were the most widely provided clinical pharmacy services. The most common services available from hospital pharmacies throughout Australia were imprest, informal drug education for hospital staff, review of medication charts, control of drug purchasing for the hospital, and inpatient dispensing.

Calcium absorption in postmenopausal osteoporosis: benefit of HRT plus calcitriol, but not HRT alone, in both malabsorbers and normal absorbers

In a randomized trial involving 71 postmenopausal osteoporotic women with vertebral compression fractures, radiocalcium absorption studies using the (45)Ca single isotope method (alpha) were performed at baseline and after 8 months of treatment with either continuous combined hormone replacement therapy (HRT, as piperazine estrone sulfate 0.625-0.937 mg daily +/- medroxyprogesterone acetate 2.5 mg daily depending on uterine status) or HRT plus calcitriol 0. 25 microg twice daily. A calcium supplement of 600 mg nocte was given to only those women who had a daily calcium intake of less than 1 g per day at baseline, as assessed by recalled dietary intake. There was a significant decrease [0.74 (+/- 0.35 SD) to 0.58 (+/- 0. 22), Dalpha = -0.17 (+/- 0.26), p<0.0005] in alpha at 8 months compared with baseline in the HRT-treated group, but a significant increase [0.68 (+/- 0.31) to 0.84 (+/- 0.27), Dalpha = +0.16 (+/- 0. 30), p<0.003] in the HRT-plus-calcitriol treated patients, resulting in alpha being significantly higher after 8 months in the latter group than in the HRT-only group. Although 72% of the patients had been supplemented with calcium between the first and second studies, separate analyses revealed that the change in calcium intake had not affected the result. Further breakdown of the groups into baseline 'normal' absorbers (alpha >/=0.55) and 'malabsorbers' (alpha <0.55) revealed that alpha decreased with HRT treatment only in the normal absorbers, and remained stable in the malabsorbers. Conversely, following HRT plus calcitriol treatment, alpha increased only in the malabsorbers, the normal absorbers in this group remaining unchanged. In conclusion, our data show that HRT, of the type and dose used in this study, did not produce an increase in absorption efficiency; it was in fact associated with a fall. Increased absorption efficiency cannot be achieved unless calcitriol is used concurrently, and then only in patients with malabsorption. Calcitriol also had a significant effect in normal absorbers in that it prevented the decline in alpha seen with HRT alone, and thus should be considered in all patients with postmenopausal osteoporosis treated with HRT.

Pharmacogenetic variability in neuronal nicotinic receptor-mediated antinociception

The ability to predict interindividual differences in drug efficacy or toxicity, based on genetic factors that influence drug disposition or drug action, is fast becoming a realistic goal. The purpose of the present study was to determine whether epibatidine, a prototypical nicotinic analgesic drug, exhibits pharmacogenetic variability in antinociceptive activity. Eight inbred mouse strains (A, AKR, BALB/c, C3H/He, C57BL/6, C57BL/10, DBA/2, and SM) were surveyed for their sensitivity to the antinociceptive effects of epibatidine. All strains exhibited statistically significant antinociception that peaked between 10 and 20 min following the systemic injection of 50 microg/kg epibatidine. However, there was fourfold variability in the magnitude of peak effect between strains, with DBA/2, BALB/c and A strains showing much greater sensitivity than all others. A return to baseline nociceptive threshold at 30 min post-injection was observed for all but the A strain. In contrast, these mice exhibited significant antinociception for at least 3 h following epibatidine administration. Thus, expressing the data as area under the time-latency curve to take into account both the magnitude and duration of effect, epibatidine displayed approximately 20-fold higher antinociceptive potency in the A strain compared with the C3H/He strain. The effects of epibatidine in both the A and C3H/He strains were dose-dependent and sensitive to antagonism by the selective neuronal nicotinic channel blocker mecamylamine. Taken together, these data demonstrate the existence of pharmacogenetic variability in neuronal nicotinic receptor-mediated antinociception between inbred stains of mice and presage the potential for similar variability in analgesic response to nicotinic-based analgesics among humans. Future studies will seek to identify the chromosomal loci underlying this variability.

Sex differences in supraspinal morphine analgesia are dependent on genotype

Several variables have been reported to affect the expression of sex differences in the analgesic potency of morphine. Although the effect of genetic background on morphine analgesia has been well documented, the relevance of genotype to sex differences in morphine analgesia has rarely been considered. The present study investigated morphine dose-response relationships in male and female mice of 11 inbred mouse strains on the tail-withdrawal test after i.c.v. administration. Large differences in morphine analgesic potency were observed between strains, reflecting the important influence of genotype on this trait. We identified three strains (AKR/J, C57BL/6J, and SWR/J) in which males displayed approximately 3.5- to 7.0-fold greater sensitivities to the analgesic effects of morphine than did their female counterparts. In contrast, in the CBA/J strain, females were found to be approximately 5-fold more sensitive to morphine than were the males. In all other strains, morphine potency estimates between the sexes were not statistically different. These data support the importance of genotype, sex, and their interaction in the mediation of morphine analgesia and suggest that equivocal findings regarding opioid sex differences in the literature may be partially accounted for by the use of different subject populations. The fact that female mice of the AKR/J and CBA/J strains exhibit 35-fold different morphine analgesic potency and that males of these strains are equally sensitive should facilitate the mapping and identification of sex-specific genes of relevance to morphine analgesia.

Heritability of nociception II. 'Types' of nociception revealed by genetic correlation analysis

Clinical pain syndromes, and experimental assays of nociception, are differentially affected by manipulations such as drug administration and exposure to environmental stress. This suggests that there are different 'types' of pain. We exploited genetic differences among inbred strains of mice in an attempt to define these primary 'types'; that is, to identify the fundamental parameters of pain processing. Eleven randomly-chosen inbred mouse strains were tested for their basal sensitivity on 12 common measures of nociception. These measures provided for a range of different nociceptive dimensions including noxious stimulus modality, location, duration and etiology, among others. Since individual members of inbred strains are identical at all genetic loci, the observation of correlated strain means in any given pair of nociceptive assays is an index of genetic correlation between these assays, and hence an indication of common physiological mediation. Obtained correlation matrices were subjected to multivariate analyses to identify constellations of nociceptive assays with common genetic mediation. This analysis revealed three major clusters of nociception: (1) baseline thermal nociception, (2) spontaneously-emitted responses to chemical stimuli, and (3) baseline mechanical sensitivity and cutaneous hypersensitivity. Many other nociceptive parameters that might a priori have been considered closely related proved to be genetically divergent.

Heritability of nociception I: responses of 11 inbred mouse strains on 12 measures of nociception

It is generally acknowledged that humans display highly variable sensitivity to pain, including variable responses to identical injuries or pathologies. The possible contribution of genetic factors has, however, been largely overlooked. An emerging rodent literature documents the importance of genotype in mediating basal nociceptive sensitivity, in establishing a predisposition to neuropathic pain following neural injury, and in determining sensitivity to pharmacological agents and endogenous antinociception. One clear finding from these studies is that the effect of genotype is at least partially specific to the nociceptive assay being considered. In this report we begin to systematically describe and characterize genetic variability of nociception in a mammalian species, Mus musculus. We tested 11 readily-available inbred mouse strains (129/J, A/J, AKR/J, BALB/cJ, C3H/HeJ, C57BL/6J, C58/J, CBA/J, DBA/2J, RIIIS/J and SM/J) using 12 common measures of nociception. These included assays for thermal nociception (hot plate, Hargreaves' test, tail withdrawal), mechanical nociception (von Frey filaments), chemical nociception (abdominal constriction, carrageenan, formalin), and neuropathic pain (autotomy, Chung model peripheral nerve injury). We demonstrate the existence of clear strain differences in each assay, with 1.2 to 54-fold ranges of sensitivity. All nociceptive assays display moderate-to-high heritability (h2 = 0.30-0.76) and mediation by a limited number of apparent genetic loci. Data comparing inbred strains have considerable utility as a tool for understanding the genetics of nociception, and a particular relevance to transgenic studies.

Strain-dependent effects of supraspinal orphanin FQ/nociceptin on thermal nociceptive sensitivity in mice

Despite much study since its discovery in 1995, the effects of orphanin FQ/nociceptin (OFQ/N), the endogenous ligand of the 'orphan' opioid receptor, on nociceptive sensitivity remain unclear. Different laboratories have variously reported hyperalgesic, analgesic, anti-analgesic or no effect of the peptide on thermal assays following supraspinal injection in rodents. We and others have argued previously that methodological inconsistencies and experimental parameters may explain some of the contradictions in the literature, especially in mice where intracerebroventricular (i.c.v.) injections proceed directly through the skull. We report presently that both the magnitude of stress-induced analgesia (SIA) produced by such i.c.v. injections, and the ability of OFQ/N to antagonize this opioid-mediated SIA, are strain-dependent. Specifically, significant injection-related SIA was observed in four of six strains studied (outbred: CD-1, SW; inbred: AKR/J, BALB/cJ, C3H/HeJ, CBA/J) on the 47.5 degrees C tail-withdrawal assay, and OFQ/N blocked this SIA in two strains. These data suggest that genetic variability among subject populations may underlie the inconsistent findings among researchers, and may in addition provide a promising avenue for future study of this novel neuromodulator.

[Phe1psi(CH2-NH)Gly2]nociceptin-(1-13)-NH2 acts as an agonist of the orphanin FQ/nociceptin receptor in vivo

The orphanin FQ/nociceptin (OFQ/N) derivative peptide, [Phe1psi(CH2-NH)Gly2] nociceptin-(1-13)-NH2 (Phe(psi)), has been claimed to be both an antagonist and an agonist of the orphan opioid receptor (ORL1) in different in vitro assays. We now report the dose-dependent inhibition of morphine analgesia by Phe(psi) in mice, an effect parallel to that of OFQ/N. Further, the anti-opioid actions of OFQ/N are not blocked by Phe(psi). Thus, Phe(psi) acts as an ORL1 receptor agonist, not an antagonist, in vivo.

The effect of genotype on sensitivity to inflammatory nociception: characterization of resistant (A/J) and sensitive (C57BL/6J) inbred mouse strains

The important role of genetic factors in the mediation of sensitivity to pain and pain inhibition is being increasingly appreciated. In an attempt to systematically study the genotypic influences on inflammatory nociception, we conducted a survey of the nociceptive responsivity of three common outbred mouse strains and 11 inbred mouse strains on the formalin test. The formalin test is known to display a biphasic temporal pattern of behavioral and electrophysiological activity, defined by an acute/early phase and a tonic/late phase. Nociceptive sensitivity (licking/biting of the affected area) to a subcutaneous injection of 5% formalin (25 microl volume) into the plantar surface of the right hindpaw displayed moderate heritability in both phases (0.38 and 0.46, respectively). One strain, A/J, was identified as extremely resistant to formalin nociception, displaying total licking in the acute and tonic phases that was 60% and 87% lower, respectively, than the grand mean of all strains. A subsequent series of experiments were performed to characterize the difference between A/J and C57BL/6J mice. The findings establish this inbred strain comparison as a useful genetic model of nociceptive sensitivity.

Adrenalitis and the adrenocortical response of resistant and susceptible mice to acute murine cytomegalovirus infection

Murine cytomegalovirus (MCMV) induces adrenalitis in BALB/c mice but does not compromise adrenal function, assessed by levels of circulating adrenocorticotropic hormone (ACTH) and by the response to challenge with synthetic ACTH. Levels of corticosterone increased 2 days after infection in mice of this strain, consistent with previously established interactions between mediators of acute inflammation and activation of the hypothalmus-pituitary-adrenal axis. Moreover, an adrenocortical response was critical to survival of BALB/c (but not C57BL/6) mice 3 days after infection, as pharmacologically or surgically adrenalectomized BALB/c mice died when given doses of virus up to fivefold lower, than they could normally tolerate. However, death could not be prevented by the administration of soluble cytokine receptors to inhibit the action of interleukin 1 (IL-1) or tumour necrosis factor alpha (TNF alpha). The corticosteroid response did not mediate.MCMV-induced thymic atrophy. As the above traits were all less evident in C57BL/6 mice, a common genetic basis is discussed.

A comparison of papillary retention versus full-thickness flaps with internal mattress sutures in anterior periodontal surgery

Esthetic considerations pose therapeutic dilemmas in the selection of surgical techniques in anterior periodontal surgery. Two surgical techniques designed to maximize postoperative esthetics in the anterior regions are described. Changes in interdental papillary height are reported and compared at 1 year postoperative. This study discusses the surgical techniques, their advantages and disadvantages, and their indications. Since there is less risk of recession and more potential for gain in papillary height, the papillary retention procedure, when possible, may be the procedure of choice in anterior regions.

The relationship between standardized psychomotor tests and basic clinical dental hygiene skills

PURPOSE

This study was designed to help dental hygiene educators identify predictors of early instrumentation achievement among preclinical students. Studies from other disciplines suggest that underlying abilities play a significant role in early skill development and that additional factors contribute to later skill development. Previous studies in the dental professions have not differentiated between early skill development and later skill development.

METHODS

Forty-five entering dental hygiene students were subjected to six psychomotor tests. In the first trimester, these same students were given three instrumentation tests (Marquis probe, 3-A explorer, and Gracey curets) by calibrated faculty. Data from the psychomotor and the instrumentation tests were then statistically examined using means, standard deviations, Pearson product-moment correlations, and stepwise regression to determine predictive validity of the ability tests for each instrumentation skill.

RESULTS

The Purdue Hand Precision Test was found to contribute significantly to use of the explorer and Gracey curets. Analysis of variance revealed that this test accounted for 17 percent of the variance on the probe examination and 22 percent on the curet examination. None of the other psychomotor tests used were predictive of early clinical skills.

CONCLUSIONS

This study suggests that hand-eye coordination, precision, and aiming, as measured by the Purdue Hand Precision Test are factors in the development of early dental hygiene instrumentation skills. Continued study in this area is indicated since early identification of clinical problems may help educators and students deal with morale and retention issues.

On the nature of streaks in signal detection

Human performance in the domain of signal detection is analyzed with respect to the formation of streaks. Streakiness was found to be a general property of auditory and visual discrimination in the sense that correct and incorrect responses have a positive sequential dependency. Success tends to follow success and failure tends to follow failure. Level of streakiness was discovered to be a function of the attentional demand required by the discrimination. Discriminations that make the least demand on attentional resources produce the highest level of streakiness. Monte-Carlo simulations of the observed data sequences suggest that streaky performance is a residue of wave-like variations in perceptual and attentional resources.

An autogenous gingival graft technique

This paper discusses a technique for root coverage using autogenous free gingival grafts. Twenty-two patients who had gingival recession on facial tooth surfaces were studied. The patients underwent surgical treatment, and pretreatment and posttreatment average probing depths for the distal, facial, and mesial tooth surfaces were compared. There was a general decrease in recession for all surfaces. Recession levels tended to remain stable for the duration of the study. There was a slight increase in recession on midfacial surfaces at 4 years that was not statistically significant.

Glucose turnover in pregnant women with acute malaria

1. Hypoglycaemia is a serious complication of falciparum malaria, especially in pregnant patients. To investigate malaria-associated changes in glucose metabolism in pregnancy, steady-state [6,6-2H2] glucose turnover and clearance were measured in 10 women (eight with uncomplicated falciparum malaria and two with vivax malaria at 16-30 weeks gestation) before treatment, after intravenous quinine infusion (patients with falciparum malaria) and in convalescence. 2. Admission basal plasma glucose concentrations were higher than those in convalescence [median (range); 4.8 (3.6-7.0) versus 4.0 (3.6-4.6) mmol/l, P = 0.02], and there was a significant fall during initial quinine treatment in patients with falciparum malaria [5.0 (4.3-7.6) to 3.6 (3.2-5.4) mmol/l, P < 0.01]. Basal plasma insulin levels were comparable at presentation and follow-up (P = 0.35) and rose an average of only 2m-units/l during quinine infusion (P < 0.05). Pretreatment glucose turnover rates [3.37 (2.57-4.16) mg min-1 kg-1] were comparable with those found in a previously reported study of non-pregnant severely ill patients [3.22 (2.12-4.82) mg min-1 kg-1, n = 11] and correlated significantly with the admission parasitaemia (P < 0.025). In the eight patients with falciparum malaria, there was a significant fall in turnover during intravenous quinine infusion [3.42 (2.58-4.16) to 2.66 [1.94-3.94) mg min-1 kg-1] whereas clearance did not change significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Physical characteristics of the hand and early clinical skills. Their relationship in a group of dental hygiene students

Twelve hand measurements were made on 45 first-year dental hygiene students within one week of their entering a dental hygiene program. Multiple regression was performed, using three clinical examinations (use of periodontal probe, use of 3-A explorer, and use of Gracey curets) as dependent variables, to assess whether or not hand measurements predicted early clinical skill development. None of the hand measurements were predictive for the explorer examination. Wrist width accounted for 13% of the variance on the probing examination and 24% of the variance on the curet examination. Finger span added 16% variance to the equation. A total of 40% variance was explained by these measures on the curet examination. Results suggest that wrist width and finger span may be important predictors of early dental hygiene clinical skill development.

Brief: Market Research Techniques-A Synopsis for Continuing Education Providers

Any organization that attempts to attract and hold customers must face the necessity of determining what people want and value, and then cater to those wants and values (Levitt, 1983). Educational providers can use these market research techniques to strengthen the design and implementation of nursing CE offerings. In addition to alleviating the monotony of pen and paper questionnaires for our learners, these techniques can strengthen our programming by gathering a wealth of information about the qualitative and quantitative nature of the needs of our customers. The marketing knowledge gained from these tools can help to ensure the continued success of our educational endeavors despite growing fiscal constraints.

Comparative study of colorimetric DNA hybridization method and conventional culture procedure for detection of Salmonella in foods

A second generation nucleic acid hybridization assay has been developed and evaluated against the conventional culture method for detection of salmonellae in foods. The assay involves a liquid hybridization with Salmonella-specific oligonucleotide probes, capture of probe:target hybrids onto a solid support (plastic dipstick), and a colorimetric end point detection. The assay can be completed in 2.5 h, following approximately 44 h of culture enrichment. One thousand samples representing 20 food types were analyzed in parallel by both methods. Samples included uninoculated test product, and product inoculated with Salmonella at 2 levels. Eighteen Salmonella serotypes were used as inocula. The data demonstrate that the colorimetric hybridization method and the conventional culture method are equivalent in their ability to detect Salmonella contamination of foods.