The effects of power toothbrushing on periodontal inflammation in a Canadian nursing home population: A randomized controlled trial.

OBJECTIVES: The aim of this study was to investigate whether twice-daily use of a rotating-oscillating power toothbrush (Oral-B Professional Care 1000™ ) in nursing home (NH) residents over a 6-week period, compared to usual care (UC), would reduce periodontal inflammation. METHODS: In this repeated measures single-blinded randomized controlled trial, 59 residents of one NH in Winnipeg, Canada, were randomized to receive either twice-daily tooth brushing with a rotating-oscillating power toothbrush (PB) or UC by caregivers. Consent was obtained from residents or their proxies. Participants had some natural teeth, periodontal inflammation, non-aggressive behaviour, no communicable diseases, were non-smokers and non-comatose. Outcomes were measured at baseline and 6 weeks, which included: inflammation (MGI, Lobene), bleeding (PBI, Loesche) and Plaque (Turesky). Comparisons of group changes in outcomes were analysed using an ANOVA with a repeated measure. RESULTS: Of 59 original study participants, one withdrew, one died prior to study commencement and three died before study completion. All oral parameters improved significantly for the remaining 54 residents over time (P<.0001), with no differences between groups. CONCLUSIONS: These results demonstrate that it is possible for caregivers to improve periodontal inflammation of residents over a 6-week period. Despite no significant group differences, periodontal inflammation of all study participants improved significantly, particularly in the reduction of bleeding, a direct measure of periodontal inflammation, which is a unique finding.

Intracellular amorphous carbonates uncover a new biomineralization process in eukaryotes.

Until now, descriptions of intracellular biomineralization of amorphous inclusions involving alkaline-earth metal (AEM) carbonates other than calcium have been confined exclusively to cyanobacteria (Couradeau et al., 2012). Here, we report the first evidence of the presence of intracellular amorphous granules of AEM carbonates (calcium, strontium, and barium) in unicellular eukaryotes. These inclusions, which we have named micropearls, show concentric and oscillatory zoning on a nanometric scale. They are widespread in certain eukaryote phytoplankters of Lake Geneva (Switzerland) and represent a previously unknown type of non-skeletal biomineralization, revealing an unexpected pathway in the geochemical cycle of AEMs. We have identified Tetraselmis cf. cordiformis (Chlorophyta, Prasinophyceae) as being responsible for the formation of one micropearl type containing strontium ([Ca,Sr]CO3 ), which we also found in a cultured strain of Tetraselmis cordiformis. A different flagellated eukaryotic cell forms barium-rich micropearls [(Ca,Ba)CO3 ]. The strontium and barium concentrations of both micropearl types are extremely high compared with the undersaturated water of Lake Geneva (the Ba/Ca ratio of the micropearls is up to 800,000 times higher than in the water). This can only be explained by a high biological pre-concentration of these elements. The particular characteristics of the micropearls, along with the presence of organic sulfur-containing compounds-associated with and surrounding the micropearls-strongly suggest the existence of a yet-unreported intracellular biomineralization pathway in eukaryotic micro-organisms.

Frequency and predictors of confirmed hypoglycaemia in type 1 and insulin-treated type 2 diabetes mellitus patients in a real-life setting: results from the DIALOG study.

AIM: DIALOG assessed the prevalence and predictors of hypoglycaemia in patients with type 1 (T1DM) or insulin-treated type 2 diabetes mellitus (T2DM) in a real-life setting. METHODS: In this observational study, insulin-treated patients (n=3048) completed prospective daily questionnaires reporting the frequency and consequences of severe/confirmed non-severe hypoglycaemia over 30 days. Patients (n=3743) also retrospectively reported severe hypoglycaemia over the preceding year. RESULTS: In this prospective survey, 85.3% and 43.6% of patients with T1DM and T2DM, respectively, reported experiencing at least one confirmed hypoglycaemic event over 30 days, while 13.4% and 6.4%, respectively, reported at least one severe event. Hypoglycaemia frequency increased with longer duration of diabetes and insulin therapy. Strongly predictive factors for hypoglycaemia were previous hypoglycaemia, >2 injections/day, BMI<30kg/m(2) and duration of insulin therapy>10 years. HbA1c level was not predictive of hypoglycaemia in either T1DM or T2DM. The confirmed hypoglycaemia rate was increased in the lowest compared with the highest tertile of HbA1c in T1DM, but not T2DM. At the time of enrolment, physicians reported severe hypoglycaemia in 23.6% and 11.9% of T1DM and T2DM patients, respectively, during the preceding year; the retrospective survey yielded frequencies of 31.5% and 21.7%, respectively. Also, severe hypoglycaemia led to medical complications in 10.7% and 7.8% of events in T1DM and T2DM patients, respectively, over 30 days. CONCLUSION: Using a unique combined prospective and retrospective approach, the DIALOG study found a relatively high frequency of hypoglycaemia among insulin-treated patients. These findings emphasize the importance of a patient-centred approach for managing diabetes in which hypoglycaemia risk evaluation is critical. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01628341.

Determinants of self-monitoring of blood glucose in patients with Type 1 diabetes: a multi-centre study in Brazil.

AIM: The aim of this study was to determine the relationship between the daily frequency of self-monitoring of blood glucose and glycaemic control, demographic and socio-economic status in patients with Type 1 diabetes under routine clinical care in Brazil. METHODS: This was a cross-sectional, multi-centre study conducted between December 2008 and December 2010 in 28 public clinics in 20 Brazilian cities. The data were obtained from 3176 patients, aged 22 ± 11.8 years, of whom 56.3% were female and 57.4% were Caucasian. The mean time since diabetes diagnosis was 11.7 ± 8.1 years. RESULTS: The prevalence of self-monitoring of blood glucose was 88.5%. There was a significant increase in self-monitoring frequency associated with female gender, lower ages, more intensive diabetes management and higher socio-economic status. A correlation between HbA(1c) levels and the daily frequency of self-monitoring was observed (r(s) = -0.13; P = 0.001). The mean HbA1c levels were related to the daily frequency of self-monitoring (P < 0.001) without additional benefit to patients who performed self-monitoring more than four times daily (9.2, 11.2, 10.2,15.2 and 15% for one, two, three, four, five or more self-monitoring tests daily, respectively; P < 0.0001). CONCLUSIONS: The majority of our patients (88.5%) performed three or more self-monitoring tests daily, with more frequent testing reported by females, younger patients, those on intensive insulin regimens and of higher socio-economic status. No additional benefit was found in patients who performed self-monitoring more than four times daily. The diabetes care team must improve patients' education regarding self-monitoring of blood glucose and its benefits.

Assessment of bacterial endospore viability with fluorescent dyes.

AIM: To validate three fluorescence viability assays designed primarily for vegetative cells on pure Bacillus endospores. METHODS AND RESULTS: Purified fresh and gamma-irradiated Bacillus endospores (Bacillus cereus, B. coagulans and two strains of B. subtilis) were used. The viability assays were: 5-cyano-2,3-diotolyl tetrazolium chloride (CTC) to test respiratory activity and early germination, DiBAC4(3) and Live/Dead BacLight to measure membrane energization and permeabilization, respectively. Gamma irradiation treatment completely eliminated spore culturability and was used as negative control. The untreated spores showed respiratory activity after 1 h of incubation and this was characteristic of almost 100% of spores after 24 h. The membrane potential assessment gave no answer about spore viability. A lower proportion of untreated spores had permeabilized membrane compared with gamma-irradiated spores using Live/Dead BacLight (P < 0.02). CONCLUSION: It is possible to use CTC and Live/Dead BacLight to rapidly test endospore viability and evaluate the proportion of spores in a preparation that could not be recovered with plate count. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that fluorescence tests could be applied to assess viability in potentially pathogenic Bacillus spore preparations within 1 h.

Endothelial cells modulate eosinophil surface markers and mediator release.

Migration from blood to tissue modulates eosinophil function, possibly through interactions with endothelial cells. The effects of contact with and migration through endothelial cells on eosinophil expression of surface markers and release of leukotriene C4 were evaluated. A small proportion (2.6%) of eosinophils spontaneously migrated through endothelial cell monolayers. Activation of endothelial cells by interleukin (IL)-4 or IL-1beta slightly increased this migration (to 12.4%), which became much greater when a chemoattractant was placed in the lower chamber (84.3%). However, the chemotactic effect was downregulated by pretreating endothelial cells with interferon gamma (IFN-gamma; 63.1%). At baseline, 5% of eosinophils expressed CD69; this increased to 30.7% in culture on untreated endothelial cells and to 50.9% on IL-1beta-pretreated endothelial cells. This effect was mediated through intercellular adhesion molecule-1/CD11b interaction. Eosinophil migration through endothelial cells further increased CD69 expression to 63.9% and also increased CD35 expression from 83.3 to 91.3%. Upon stimulation, eosinophils that had migrated through endothelial cells produced more leukotriene C4 than control cells (872.4 and 103.9 pg x mL(-1), respectively). Endothelial cell pretreatment with IL-4 or IL-1beta further increased leukotriene C4 release (1,789.1 and 2,895.1 pg x mL(-1), respectively), whereas pretreatment with IFN-gamma decreased it (293.7 pg x mL(-1)). These data show that in vitro interactions with endothelial cells upregulate eosinophil membrane receptor expression and mediator release and that these effects are differently modulated by T-helper cell type 1 and 2 cytokines. These eosinophil modulations may play an important role in asthma pathogenesis.

Migration through basement membrane modulates eosinophil expression of CD44.

BACKGROUND: Tissue eosinophils express more membrane receptors and release more mediators than blood eosinophils, suggesting that migration from blood to tissue modulates eosinophil phenotype and functions. OBJECTIVE: We postulated that eosinophil passage through endothelial basement membrane, an important step of eosinophil migration into tissue, may be responsible for some of these changes. METHOD: We previously showed that 5-oxo-6, 8, 11, 14-eicosatetraenoic acid (5-oxo-ETE) in combination with IL-5 promotes eosinophil migration through Matrigel, a mouse tumour cell-derived basement membrane. Using this model, we evaluated the effect of trans-Matrigel migration on purified human blood eosinophil expressions of CD44, CD69 and HLA-DR that either increase or appear on activated eosinophils, and releases of peroxidase (EPO), leukotriene (LT) C(4) and granulocyte-monocyte colony stimulating factor (GM-CSF). RESULTS: IL-5, but not 5-oxo-ETE, increased eosinophil expression of CD44 and CD69. Migration of eosinophils through Matrigel significantly increased CD44 expression level over the one induced by IL-5 (P = 0.0001). Migration through Matrigel did not modify CD69 expression compared with the one obtained in the presence of IL-5 alone; however, incubation of eosinophils on Matrigel decreased IL-5-induced CD69 (P = 0.0001). Trans-Matrigel migration did not modify HLA-DR expression, nor EPO, LTC(4) and GM-CSF releases. CONCLUSION: These data show that in vitro trans-Matrigel migration and Matrigel contact modulate eosinophil membrane receptor expression. Consequently, they suggest that migration through basement membrane mediates changes in cell-surface phenotype observed on activated eosinophils and probably prepares them for interactions with tissue components and cells.

Pregnancy outcome following gestational exposure to venlafaxine: a multicenter prospective controlled study.

OBJECTIVE: Because there are no studies available on the safety of venlafaxine during pregnancy, the authors' goal in this study was to determine whether venlafaxine increases the risk for major malformations. METHOD: Data on 150 women exposed to venlafaxine during pregnancy in seven pregnancy counseling centers were compared with data from studies of pregnant women who 1) received selective serotonin reuptake inhibitor antidepressants (SSRIs) (N=150) and 2) who received nonteratogenic drugs (N=150). RESULTS: Among the 150 women who were exposed to venlafaxine during pregnancy, 125 had live births, 18 had spontaneous abortions, and seven had therapeutic abortions; two of the babies had major malformations. There were no significant differences between these women and the two comparison groups on any of the measures analyzed. CONCLUSIONS: These results suggest that the use of venlafaxine during pregnancy does not increase the rates of major malformations above the baseline rate of 1%-3%.

5-Oxo-6,8,11,14-eicosatetraenoic acid induces important eosinophil transmigration through basement membrane components: comparison of normal and asthmatic eosinophils.

Basement membrane transmigration is an important step in tissue recruitment of eosinophils into inflamed tissue. Recent reports showed that this phenomenon is modulated by platelet-activating factor (PAF) in combination with cytokines and proteinases. We investigated the in vitro efficacy of 5-oxo-6,8,11, 14-eicosatetraenoic acid (5-oxo-ETE), a metabolite of arachidonic acid and known as a potent eosinophil chemotactic factor, in promoting the transmigration of blood eosinophils from normal and asthmatic subjects through a Matrigel basement membrane. 5-Oxo-ETE proved to be a more potent (> 10-fold) inducer of eosinophil transmigration than PAF, and this effect was similar in cells from normal and asthmatic subjects (82.0 +/- 3.7% and 88.1 +/- 3.7%, respectively). Moreover, 5-oxo-ETE was active in the absence of interleukin (IL)-5, although this cytokine amplified the effect of 5-oxo-ETE from 61.3 +/- 3.3% to 92.8 +/- 1.8% (p = 0.003). The membrane receptor for urokinase plasminogen activator (CD87), a serine protease, was observed on eosinophils, and its expression was increased by IL-5. The inhibition of both metalloproteinases (MMP) and plasmin/plasminogen complex with inhibitor or monoclonal antibodies decreased cell transmigration by about 50%. Combination of an MMP inhibitor with anti-CD87 antibodies had no additive effect. These data show that 5-oxo-ETE is an efficient promoter of eosinophil transmigration in vitro, and is much more potent in this respect than PAF. The data suggest that 5-oxo-ETE could play an important role in eosinophil recruitment in vivo. Moreover, they demonstrate that in addition to MMP, the plasmin/plasminogen system could be involved in eosinophil transmigration.

Expression of costimulatory molecules on alveolar macrophages in hypersensitivity pneumonitis.

To verify whether alveolar macrophages (AM) of patients with hypersensitivity pneumonitis (HP) increase their antigen-presenting capacity by upregulating the expression of B7 costimulatory molecules (CD80, CD86), and whether a viral infection enhances this expression whereas cigarette smoking abrogates it, we performed bronchoalveolar lavage (BAL) on 18 patients with HP; 10 asymptomatic, virus-exposed subjects (AS); 18 nonsmokers; and 12 smokers. Influenza virus infection of AM from nonsmokers and smokers was induced in vitro. Expression of CD80 and CD86 on AM, and of CD28 and CTLA4 on T cells, was evaluated. The percentage of CD80(+) AM was greater in HP patients (34.6 +/- 7.7) and in AS (23.9 +/- 7.6) than in nonsmokers (6.7 +/- 1.6) or smokers (2.5 +/- 0.3). An increase in CD86(+) cells (62.3 +/- 5.9) was found in HP patients as compared with nonsmokers (24.2 +/- 3.8) and smokers (4.5 +/- 1.0). CD28 and CTLA4 molecules were highly expressed on all T cells. In vitro virus infection upregulated CD80 and CD86 expression in AM of normal nonsmoking subjects but not on those of smokers. These results suggest that: (1) an upregulation of B7 molecule expression is involved in the lymphocytic alveolitis of HP; (2) a viral infection could enhance HP by increasing B7 expression; and (3) the protective effect of cigarette smoking in HP may be due to the low level of expression of costimulatory molecules on AM from smokers, and to their resistance to further upregulation.

Dental hygienists in multidisciplinary health care.

The evolving roles and responsibilities of the dental hygiene profession are placing very different demands on its members. Collaboration with other health professionals will become necessary as the profession moves forward into more interdisciplinary settings. The purpose of this paper is to describe a recently published study involving collaboration between dental hygienists, physician assistants and physical therapists. Multidisciplinary teams comprised of representatives from each of the three professions participated in both a simulated problem-based case assessment and a real life patient assessment. Results showed favourable learning experiences by all three disciplines which could serve as a potential model for future multidiscipline projects. Collaborations between health professionals have the potential to enhance client care and ultimately improve their quality of life.

Geriatric education in dental hygiene programs.

This study examined the current status of geriatric curricula in dental hygiene programs in both the United States and Canada and was comprised of a twenty-six-item survey sent to dental hygiene programs. Responses (82 percent) revealed didactic requirements in 89 percent of programs and clinical requirements in 54.2 percent of programs surveyed. Mean didactic clock hours were ten (+/- 8.2), while clinical clock hours were 21.8 (+/- 27.5). Specific geriatric courses were found in only 18.8 percent of programs, while 81.2 percent integrated geriatrics with other coursework. Both clinical (98.8 percent) and didactic courses (81.5 percent) were taught primarily by dental hygiene faculty. Clinical experiences were primarily provided at extramural sites (79 percent). Half of schools surveyed (49.5 percent) felt their geriatric curriculum was less than optimal. The authors conclude that current levels of geriatric dental hygiene education may not meet the increasing demands of this growing population.

Identification and analysis of eosinophils by flow cytometry using the depolarized side scatter-saponin method.

This study describes a method for flow cytometric (FCM) identification and analysis of eosinophils (EOS) in mixed granulocyte populations without the need of further cell purification. Granulocytes were prepared from 10 ml blood samples obtained from 14 non-atopic healthy subjects and 16 hypereosinophilic subjects. The cells were fixed in paraformaldehyde (PFA) and permeabilized with either saponin or n-octyl-beta-D-glucopyranoside (OG) before FCM. Side scatter light (SS) and depolarized sideward light scatterings (dSS) were measured before and after granulocyte fixation and permeabilization. Based on autofluorescence of cells, EOS were depicted in forward scatter (FS)-SS and FS-dSS cytograms. FS-dSS analysis of PFA-saponin-treated cells provided the best discrimination between EOS (high dSS) and neutrophils (low dSS) in normal and hypereosinophilic blood samples (n = 22). Subsequent sorting and differential staining of the two populations further confirmed cell identity in high dSS (97.2 +/- 3.0% EOS) and low dSS (99.6 +/- 0.5% neutrophils) PFA-saponin-treated cells (n = 5). Similar FS-dSS profiles were obtained for hypodense (HBSS-1.082 g/ml interface) and normodense (1.082-1.100 g/ml interface) EOS separated by centrifugation on discontinuous Percoll gradients and treated with PFA-saponin. Using this method, we successfully detected the cytokines interleukin-2 (IL-2), IL-4, IL-5, and interferon gamma (IFN gamma) in blood EOS of normal and hypereosinophilic subjects (n = 12). In conclusion, this method allows the analysis of EOS intracellular antigens in mixed granulocyte populations obtained from small blood samples. This analysis is not affected by the buoyant density of eosinophils, and can therefore be applied for the analysis of blood EOS in various types and severities of diseases.

Effects of tartar-control dentifrice on tooth sensitivity: a pilot study.

PURPOSE: The purpose of this three-week, double-blind pilot study was to assess the effects of a tartar-control dentifrice on tooth sensitivity. METHOD: Fifty-six volunteer dental hygiene students completed a 14-item questionnaire regarding their oral health. Eighteen students were excluded from the study due to prior tooth sensitivity. Thirty-eight students were randomly assigned to either the experimental group using a tartar-control dentifrice (containing tetrapotassium pyrophosphate, PEG-6, disodium pyrophosphate, and tetrasodium pyrosulphate in a 5.0% soluble pyrophosphate formulation) or the control group using a regular dentifrice. Participants brushed for three weeks twice daily and then completed a post-treatment questionnaire, which included questions about tooth sensitivity. Differences between groups in reported sensitivity were measured by Fisher's Exact Test. RESULTS: Fisher's Exact Test revealed a statistically significant difference in sensitivity experienced by the experimental group compared to the control group (p < 0.05), which reported no sensitivity. The phi coefficient, used to examine the strength of the relationship between tartar control paste and tooth sensitivity, was found significant at p < 0.02. CONCLUSION: These findings suggest that patients may experience dentinal hypersensitivity when using the tartar-control toothpaste tested. Further long-term studies are required to test various brands of tartar-control dentifrice with a larger, more diverse sample for clinical measures of sensitivity.

Breaking down barriers: multidisciplinary education model.

A pilot project was implemented involving students from three disciplines: dental hygiene, physical therapy, and physician assistant. The purpose was to prepare students to work together in multidiscipline teams utilizing concepts of problem-based learning (PBL) on both simulated and real patients. The project was divided into three phases. Phase I introduced discipline specific information, team concepts, and PBL concepts. Phase II involved students working in multidisciplinary teams solving a simulated patient case in the PBL format. Phase III consisted of students working in small groups and on real patients, performing an extraoral/intraoral and periodontal examination, a problem oriented physical examination, and a neuromuscular assessment. Pre and posttest evaluation of Phase I revealed no difference in knowledge among the three disciplines. Of those students evaluating Phase II and III, 100% felt PBL was an effective means of presenting multidisciplinary material; 93% reported enhanced problem-solving; 98% indicated improvements in working in groups; and 98% felt they had learned more about each other's discipline. This model may provide a viable means to prepare interdisciplinary teams to work effectively together.

Gene expression of interleukin-2 in purified human peripheral blood eosinophils.

To verify the hypothesis that eosinophils produce interleukin-2 (IL-2), a cytokine essential for lymphocyte activation, the expression of IL-2 was examined in peripheral blood eosinophils obtained from normal, atopic, asthmatic and hypereosinophilic subjects. Purified blood cell preparations were > 95% eosinophils, the remaining cells being neutrophils. Based on morphological observations and on CD3 expression, no lymphocytes were detected in these eosinophil preparations. The expression of IL-2 mRNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR) in total RNA extracted from purified eosinophils stimulated with granulocyte-macrophage colony-stimulating factor (GM-CSF), with or without calcium ionophore (A23187). In-cell RT-PCR combined with in situ hybridization further confirmed that it was the eosinophils that expressed IL-2 mRNA. Moreover, in this experiment IL-2 mRNA expression increased upon costimulation with A23187 and GM-CSF suggesting that a steady-state level of IL-2 mRNA was inducible. Finally, IL-2 was detected in purified eosinophils by immunochemistry. These data, obtained by different techniques, demonstrate that eosinophils can express IL-2. An IL-2-mediated eosinophil-lymphocyte interaction could contribute to the chronic state of cell activation in inflamed tissues where these cells are implicated.

Effects of subgingival irrigation with chlorhexidine on the periodontal status of patients with HA-coated integral dental implants.

The purpose of this study was to examine the effect of chlorhexidine irrigation on the periodontal status of patients with HA-coated dental implants as measured by clinical, microbiological, and immunological measures. Thirty non-adjacent implants were randomly assigned to receive a one-time irrigation with either 0.12% chlorhexidine or sterile saline, or no irrigation. All parameters were measured at baseline, 2, 5, and 8 weeks. Results showed no significant differences between any treatment modalities at any time interval. A statistically significant decrease in probing depth (P < .05) occurred within the chlorhexidine and no-treatment groups at all time intervals compared to baseline.

Comparison of two modified techniques for purifying blood eosinophils.

As there is much heterogeneity in the morphology and function of blood eosinophils, comparison of their properties between groups of subjects requires recovering the majority of these cells. In two currently used techniques to isolate eosinophils, blood granulocytes are processed either on Percoll gradients after an incubation of granulocytes with 10(-8) M N-formyl-methionyl-leucyl-phenylalanine (fMLP) or on a magnetic cell sorter (MACS). In this study, these techniques were modified to increase the efficiency of eosinophil recovery. With the Percoll gradients, using 1.078 g/ml as the top gradient instead of 1.082 g/ml doubled the eosinophil recovery from 43 +/- 5.3% (mean +/- SEM) to 86.9 +/- 2.9%, without decreasing the purity (96.1 +/- 1.4% versus 96.2 +/- 0.9%). With a MACS, the neutrophils in granulocytes obtained on Ficoll-Paque (1.077 g/ml) instead of on Percoll gradient 1.082-1.094 g/ml, were tagged with anti-CD16 antibodies and eliminated by passing them through a magnetic field. When blood eosinophils of the same subjects were isolated using the two techniques, similar recovery and purity levels were obtained: Percoll gradients, 72.7 +/- 6.8% and 92.5 +/- 2.2%; MACS, 80.2 +/- 5.1% and 90.4 +/- 3.8%. Eosinophils isolated through the two techniques were also compared for their production of superoxide anion and leukotriene (LT) C4, with and without pre-incubation with cytokines interleukin-3, interleukin-5 and granulocyte-macrophage colony stimulating factor. The release of these products was similar between the two eosinophil preparations under all conditions tested except for interleukin-3 where eosinophils isolated with a MACS produced more LTC4. These results show that both techniques efficiently recover pure eosinophils. Furthermore, cell incubation with 10(-8) M fMLP did not enhance superoxide anion and LTC4 production nor modify the response to cytokines. The two modified techniques are therefore suitable for comparative studies of eosinophils from different groups of subjects.

Sexual differences in kappa opioid receptor-mediated regulation of tuberoinfundibular dopaminergic neurons.

The purpose of the present study was to examine the acute effects of kappa opioid receptor blockade or activation on the activity of tuberoinfundibular dopaminergic (TIDA) neurons in gonadally-intact or castrated male and female rats. In the absence of drug treatment, the basal activity of TIDA neurons (accumulation of 3,4-dihydroxyphenylalanine, DOPA, in the median eminence after administration of a decarboxylase inhibitor) in male rats was approximately one third of that in diestrous females. In male rats, blockade of kappa opioid receptors following administration of the kappa antagonist norbinaltorphimine (NOR-BNI) increased the activity of TIDA neurons suggesting that these neurons are tonically inhibited by endogenous kappa opioids. By contrast, NOR-BNI had no effect on TIDA neuronal activity in gonadally-intact diestrous female rats, but increased the activity of these neurons in ovariectomized female rats. These results suggest that ovarian hormones block the inhibitory effects of endogenous kappa opioids on the activity of TIDA neurons. Activation of kappa opioid receptors following administration of the kappa agonist U-50,488 caused a dose-related decrease in TIDA neuronal activity in diestrous female rats. U-50,488 had no effect on TIDA neuronal activity in gonadally-intact male rats, but decreased the activity of these neurons in orchidectomized male rats. Taken together, these results reveal a sexual difference in the responsiveness of TIDA neurons to kappa opioid receptor agonists and antagonists, and suggest that gonadal steroid-induced gender differences in the basal activity of TIDA neurons may be due, in part, to differences in tonic inhibitory regulation of these neurons by endogenous kappa opioids.