Developmental changes in distribution of γ-aminobutyric acid- and glycine-immunoreactive boutons on rat trigeminal motoneurons. I. Jaw-closing motoneurons

We have previously described the distribution pattern of inhibitory synapses on rat jaw-closing (JC) alpha- and gamma-motoneurons. In the present study, we investigated developmental changes in inhibitory synapses on JC motoneurons. We performed a quantitative ultrastructural analysis of putative inhibitory synaptic boutons on JC motoneuron somata by using postembedding immunogold labeling for GABA and glycine. In total, 206, 350, and 497 boutons contacting JC motoneuron somata were analyzed at postnatal days 2 (P2), 11 (P11) and 31 (P31), respectively. The size of the somata increased significantly during postnatal development. The size distribution was bimodal at P31. Mean length of the boutons and percentage of synaptic covering also increased during postnatal development, whereas bouton density did not differ significantly among the three age groups. Synaptic boutons on the somata of JC alpha-motoneurons could be classified into four types: boutons immunoreactive for 1) GABA only, 2) glycine only, 3) both GABA and glycine, and 4) neither GABA nor glycine. There was no developmental change in the proportion of putative inhibitory boutons to the total number of studied boutons. However, the glycine-only boutons increased significantly (15.1% to 27.3%), and the GABA-only boutons decreased significantly (17.7% to 2.6%) during the period from P11 to P31. Our ultrastructural data indicate that the inhibitory synaptic input to JC motoneurons is developmentally regulated and that there is a postnatal switch from GABA to glycine. The postnatal changes revealed in the present study could play an important role in the maturation of the oral motor system.

Peripheral mGluR5 antagonist attenuated craniofacial muscle pain and inflammation but not mGluR1 antagonist in lightly anesthetized rats

The present study investigated the role of peripheral group I metabotropic glutamate receptors (mGluRs) in MO-induced nociceptive behaviour and inflammation in the masseter muscles of lightly anesthetized rats. Experiments were carried out on male Sprague-Dawley rats weighing 300-400 g. After initial anesthesia with sodium pentobarbital (40 mg/kg, i.p.), one femoral vein was cannulated and connected to an infusion pump for intravenous infusion of sodium pentobarbital. The rate of infusion was adjusted to provide a constant level of anesthesia. Mustard oil (MO, 30 microl) was injected into the mid-region of the left masseter muscle via a 30-gauge needle over 10s. After 30 microl injection of 5, 10, 15, or 20% MO into the masseter muscle, the total number of hindpaw shaking behaviour and extravasated Evans' blue dye concentration in the masseter muscle were significantly higher in the MO-treated group in a dose-dependent manner compared with the vehicle (mineral oil)-treated group. Intramuscular pretreatment with 3 or 5% lidocaine reduced MO-induced hindpaw shaking behaviour and increases in extravasated Evans' blue dye concentration. Intramuscular pretreatment with 5 mM MCPG, non-selective group I/II mGluR antagonist, or MPEP, a selective group I mGluR5 antagonist, produced a significant attenuation of MO-induced hindpaw shaking behaviour and increases in extravasated Evans' blue dye concentration in the masseter muscle while LY367385, a selective group I mGluR1 antagonist, did not affect MO-induced nociceptive behaviour and inflammation in the masseter muscle. These results indicate that peripheral mGluR5 plays important role in mediating MO-induced nociceptive behaviour and inflammation in the craniofacial muscle.

Intracisternal administration of mitogen-activated protein kinase inhibitors reduced IL-1β-induced mirror-image mechanical allodynia in the orofacial area of rats

The present study investigated the role of central mitogen-activated protein kinases (MAPKs) in interleukin-1beta (IL-1beta)-induced mirror-image mechanical allodynia in the orofacial area. Experiments were carried out on Sprague-Dawley rats. Under pentobarbital sodium anesthesia, a polyethylene tube was implanted in the subcutaneous area of one vibrissa pad, which enabled us to inject IL-1beta. For an intracisternal injection, each anesthetized rat was mounted on a stereotaxic frame and a polyethylene tube was implanted. Animals were given a recovery time of at least 72 h from surgery. After a subcutaneous administration of 0.01, 0.1, 1, or 10 pg of IL-1beta, we examined the face withdrawal behavioral responses produced by 10 successive trials of air puffs ipsilateral or contralateral to the IL-1beta injection site. Normal animals did not respond to pressure less than 40 psi. The thresholds of air puffs ipsilateral and contralateral to the IL-1beta injection site were significantly lower in the IL-1beta-treated group, compared with the vehicle-treated group. The decrease in the threshold of air puffs appeared 10 min after an IL-1beta injection and persisted for over 3h. Intracisternal pretreatment with PD98059, a p44/42 MAPK inhibitor, or SB203580, a p38 MAPK inhibitor, significantly reduced the decrease in the threshold of air puffs ipsilateral to the IL-1beta injection site produced by 10 pg of IL-1beta. IL-1beta-induced mirror-image mechanical allodynia was also reduced significantly by intracisternal pretreatment with both PD98059 and SB203580. These results indicate that central MAPK pathways mediate IL-1beta-induced mirror-image mechanical allodynia in the orofacial area.

Ultrastructure of jaw muscle spindle afferents within the rat trigeminal mesencephalic nucleus

This study examined the ultrastructures of neuronal elements within trigeminal mesencephalic nucleus by labeling masseteric mesencephalic neurons and masseter motoneurons with injection of horseradish peroxidase into masseteric muscle. Of eight horseradish peroxidase-labeled muscle spindle afferents examined, four terminals showed synaptic contact with labeled dendrites of masseteric motoneurons, two with labeled somata, and the remaining two with unlabeled dendrites. A few of the labeled dendrites showed intimate contact with the somata of the trigeminal mesencephalic nucleus neurons. These results provide morphological evidence of synaptic contact of recurring masseteric muscle spindle afferents with the trigeminal mesencephalic nucleus somata and also suggest the presence of electrical synapses between the somata of the trigeminal mesencephalic nucleus neurons and dendrites of jaw-closing motoneurons.

Intracisternal administration of chemokines facilitated formalin-induced behavioral responses in the orofacial area of freely moving rats

The present study investigated the effects of intracisternal administration of MCP-1, Rantes or IL-8 on pain transmission in the orofacial area. We also investigated mechanisms of hyperalgesic responses produced by intracisternal administration of IL-8. An orofacial formalin test was employed to assess the effects of chemokines on nociceptive processing. For each animal, the number of behavioral responses and the time spent grooming, rubbing and/or scratching the facial region proximal to the formalin injection site was recorded for nine successive 5-min intervals. Intracisternal administration of MCP-1, Rantes or IL-8 significantly increased formalin-induced scratching behavioral responses in the orofacial area. Intracisternal pretreatment with indomethacin, a non-selective cyclooxygenase inhibitor, did not block IL-8-induced hyperalgesia. Pretreatment with 100 microg propranolol, a non-selective beta-adrenergic receptor antagonist and 50 microg atenolol, a selective beta(1)-adrenergic receptor antagonist, inhibited the number of scratches and the duration of scratching produced by 1 ng of IL-8 injected intracisternally. These results indicate that intracisternal administration of chemokines produce a hyperalgesic response with an orofacial inflammatory pain model and that the IL-8-induced hyperalgesia is mediated by central beta(1)-adrenergic receptor.

Quantitative analysis of tooth pulp afferent terminals in the rat brain stem

This study analyzed quantitatively the ultrastructural features of tooth pulp afferent terminals and their presynaptic axonal endings (p-endings) in the trigeminal principal (Vp), dorsomedial oral (Vdm), and caudal nuclei (Vc). Mitochondrial volume, active zone area, apposed surface area, and vesicle number were highly correlated with afferent bouton volume. The afferent bouton volume varied widely in Vp, compared to that in Vdm and Vc. The values of all parameters of p-endings were within a narrow range, and were smaller than those of afferent boutons. The afferent bouton volume correlated with the number of postsynaptic dendrites and p-endings. These results suggest that pulpal afferent information is regulated in a unique manner in the each trigeminal sensory nucleus.

GABA and glycine in synaptic microcircuits associated with physiologically characterized primary afferents of cat trigeminal principal nucleus

Previous studies suggest that sensory information conveyed through trigeminal afferents is more strongly controlled at the level of the first synapse by GABA-mediated presynaptic mechanisms in the trigeminal principal sensory nucleus (Vp) than other sensory nuclei. However, it is unknown if such a mechanism is common to functionally different classes of primary afferent in the same nucleus or across the nuclei. To address these issues, the present study focused on synaptic microcircuits associated with slowly adapting (SA) mechanosensory afferents innervating the periodontal ligaments in the cat Vp and attempted to examine GABA, glycine, and glutamate immunoreactivity in axon terminals involved in the circuits. Afferents were physiologically characterized before injection of horseradish peroxidase (HRP) and preparation for electron microscopy. HRP-labeled afferent boutons were serially sectioned and immunostained with antibodies against GABA, glycine, and glutamate using a postembedding immunogold method. All the afferent boutons examined contacted non-primary dendrites and they were frequently postsynaptic to unlabeled axons (p-endings). Axodendritic and axoaxonic contacts per afferent bouton were 1.3 (46/35) and 2.0 (70/35), respectively. Most p-endings were immunoreactive for GABA (63/70) and also glycine was co-stained in the majority of the p-endings (49/63). Thirty percent of p-endings with the colocalization of GABA and glycine participated in synaptic triads where a p-ending formed a synapse with the same dendrite as the afferent bouton. None of the p-endings was immunoreactive for glutamate. Most afferent boutons were enriched with glutamate but were immunonegative for GABA and glycine. This study provides evidence suggesting that transmission from SA afferents is strongly controlled presynaptically by GABAergic interneurons with colocalized glycine, and that a proportion of these interneurons, involved in synaptic triads, may also have postsynaptic inhibitory actions on target neurons of the SA afferents.

Intracisternal NMDA produces analgesia in the orofacial formalin test of freely moving rats

The present study was performed to investigate the antinociceptive response to the intracisternal administration of NMDA in the orofacial area. To achieve this purpose, the effects of NMDA injected intracisternally on the orofacial formalin test were monitored in freely moving rats. We also investigated underlying the mechanisms of NMDA-induced antinociceptive response. Experiments were carried out on 80 male SD rats and surgical procedures were performed under pentobarbital sodium (40 mg/kg, i.p.). Fifty microliters of 5% formalin was applied subcutaneously to the vibrissa pad without any restraining of the animals. For each animal, the number of noxious behavioral responses and the time spent grooming, rubbing, and/or scratching the facial region proximal to the injection site were recorded for nine successive 5-min intervals. The orofacial formalin responses showed two distinct phases separated by a time of relative inactivity. Intracisternal administration of NMDA produced intense scratching behavioral responses with dose related manner. NMDA injected intracisternally 30 min prior to formalin injection, however, inhibited noxious behavioral responses produced by a formalin injection significantly. Pretreatment with naloxone 20 min prior to NMDA injection abolished the inhibition of number of scratches and the duration of scratching produced by the intracisternal injection of NMDA in the late phase. Pretreatment with L-NAME, NO synthesis inhibitor, however, did not affect the antinociceptive response produced by NMDA injected intracisternally. These results suggest that NMDA injected intracisternally produces brief pain behavioral responses and also produces delayed antinociceptive effects in the orofacial formalin test. The opioid pathway seems to be involved in the NMDA-induced antinociception in the orofacial area.

Interleukin-1β injected intracisternally inhibited NMDA-evoked behavioral response in the orofacial area of freely moving rats

The brain-derived interleukin-1beta (IL-1beta) has been involved in the modulation of nociceptive processing. The direction of the effects, however, analgesia or hyperalgesia, is controversial. Here, we report the role of IL-1beta injected intracisternally in orofacial pain transmission. Experiments were carried out on 90 male SD rats and surgical procedures were performed under pentobarbital sodium. Intracisternal injection of 0.3 or 0.6 microg of N-methyl-d-aspartic acid (NMDA) produced intense scratching behavioral responses including vocalization, agitation and a desire to escape in a dose-related manner. The intracisternal injection of 1 or 10 ng IL-1beta significantly decreased the NMDA-evoked scratching behavioral responses. Pretreatment with an IL-1 receptor antagonist or naloxone, an opioid receptor antagonist, blocked the IL-1beta-induced antinociceptive response. These results suggest that cytokine injected intracisternally seems to produce antinociceptive effects in the NMDA-evoked pain model of the orofacial area and the antinociceptive effect seems to be mediated by an opioid pathway.

Peripheral glutamate receptors participate in interleukin-1β-induced mechanical allodynia in the orofacial area of rats

The present study was performed to examine peripheral cytokine-induced mechanical allodynia in the orofacial area and to investigate whether peripheral excitatory amino acids participate in the cytokine-induced mechanical allodynia. Experiments were carried out on male Sprague-Dawley rats. After interleukin-1beta (IL-1beta) was applied subcutaneously to the orofacial area, we examined withdrawal responses produced by air puffs applied to the IL-1beta injection site. The threshold of air puffs that produced withdrawal behavioral responses decreased significantly in a dose-dependent manner after injection of IL-1beta. Pretreatment with an IL-1 receptor antagonist abolished the decrease in the threshold of air puffs. Pretreatment with dl-2-amino-5-phosphonvaleric acid, an N-methyl-d-aspartic acid (NMDA) receptor antagonist, did not affect IL-1beta-induced mechanical allodynia. However, pretreatment with 6,7-dinitroquinoxaline-2,3-dione, a non-NMDA receptor antagonist, abolished the decrease in the threshold of air puffs. These results suggest that peripheral cytokine can produce mechanical allodynia in the orofacial area and that excitatory amino acids can modulate IL-1beta-induced mechanical allodynia via non-NMDA receptors.

Central cyclooxygenase-2 participates in interleukin-1β-induced hyperalgesia in the orofacial formalin test of freely moving rats

The present study was performed to investigate effects of central cyclooxygenase (COX) on interleukin (IL)-1beta-induced hyperalgesia in the orofacial area. Experiments were carried out on 72 male Sprague-Dawley rats weighing 220-280 g. Surgical procedures were performed under pentobarbital sodium. We examined noxious behavioral scratching responses induced by 50 microl of 5% formalin injected subcutaneously into the vibrissa pad without any restraints. The orofacial formalin responses exhibited two distinct phases with early responses (0-10 min) and continuous prolonged responses (11-45 min). Intracisternal injection of 100 pg IL-1beta significantly increased noxious behavioral responses. Pretreatment with indomethacin, a non-selective COX inhibitor, or NS-398, a selective COX-2 inhibitor, blocked IL-1beta-induced hyperalgesic responses. However, pretreatment with SC-560, a selective COX-1 inhibitor, did not change hyperalgesic response to IL-1beta. These data suggest that central IL-1beta modulates the transmission of nociceptive information in the orofacial area and that central COX-2 plays an important role in IL-1beta-induced hyperalgesia.

Effects of TNF-alpha injected intracisternally on the nociceptive jaw-opening reflex and orofacial formalin test in freely moving rats

The present study was performed to investigate the effects of central cytokines on the modulation of nociception in the orofacial area. A nociceptive jaw-opening reflex (JOR) and an orofacial formalin test were monitored after intracisternal administration of tumor necrosis factor (TNF)-alpha in freely moving rats. Experiments were carried out on 83 male rats weighing 300-350 g and surgical procedures were performed under pentobarbital sodium. After intracisternal injection of Tnf-alpha, digastric electromyogram (dEMG) and noxious behavioral responses were monitored. In the nociceptive JOR, dEMG was not significantly changed after intracisternal injection of 200 pg and 2 ng Tnf-alpha. However, 20 ng Tnf-alpha suppressed dEMG to 72+/-6% of the control values. The orofacial formalin responses showed two distinct phases separated by a time of relative inactivity with an early short-lasting response (0-9 min, first phase) and a continuous prolonged response (10-45 min, second phase). In the inflammatory orofacial formalin test, intracisternal injection of 20 pg Tnf-alpha did not change the number of noxious behavioral responses produced by formalin injection. However, 200 pg Tnf-alpha injected intracisternally significantly increased the number of noxious behavioral responses produced by formalin injection in both the early and late phases, and 2 ng Tnf-alpha increased formalin induced noxious behavioral responses in only the late phase. A higher dose of 20 ng Tnf-alpha did not change the number of noxious behavioral responses produced by formalin injection. The hyperalgesic action of Tnf-alpha injected intracisternally was blocked by pretreatment with the interleukin-1 (IL-1) receptor antagonist. These results suggest that central Tnf-alpha modulates the transmission of nociceptive information in the orofacial area. However, the hypo/hyperalgesic response of central Tnf-alpha seems to depend on the orofacial pain model or in a dose-related manner. The hyperalgesic response of central Tnf-alpha seems to be mediated by the IL-1 receptor.

Immortalization of human embryonic fibroblasts by overexpression of c-myc and simian virus 40 large T antigen

SV40 large T antigen, a viral oncoprotein, is known to immortalize human diploid fibroblast by soaking up cellular RB and p53, but its frequency is extremely low. Additional genetic alteration is necessary for single-step immortalization. We attempted to find out what this alteration is by overexpressing cellular signal mediator genes; c-myc and cyclin D frequently amplified in many cancer cells. Overexpression of cyclin D did not affect the immortalization, but, overexpression of c-myc along with T antigen could immortalize normal human diploid fibroblast. Several cellular markers tested during immortalization process showed that p21, a cyclin-dependent kinase inhibitor and a marker of cellular senescence, disappeared in the life span-extended cells by T antigen and in the immortalized cells by c-myc. p21 was, however, elevated in the senescent cells and in the cells of crisis. Interestingly, p16 was upregulated whenever T antigen is overexpressed. Telomerase activity was also activated only in the immortalized cells. These results suggest that overexpression of c-myc contributes to immortalization of human diploid fibroblast by activating telomerase activity and suppressing p21 activity.

Cytoprotective effect of Scutellaria baicalensis in CA1 hippocampal neurons of rats after global cerebral ischemia

Based on the use of Scutellaria baicalensis for the treatment of stroke in traditional Oriental medicine, the current study was carried out to evaluate neuroprotective effects of S. baicalensis after transient global ischemia using rat 4-vessel occlusion model. Methanol extracts from the dried roots of S. baicalensis (0.1-10 mg/kg) administered intra-peritoneally significantly protected CA1 neurons against 10 min transient forebrain ischemia as demonstrated by measuring the density of neuronal cells stained with Cresyl violet. Methanol extract of S. baicalensis inhibited microglial tumor necrosis factor-alpha (TNF-alpha) and nitric oxide production, and protected PC12 cells from hydrogen peroxide-induced toxicity in vitro.

A case of cutaneous bronchogenic cyst over the left scapula

Bronchogenic cyst is noted shortly after birth or in early childhood and usually presents as a swelling or draining sinus in the presternal area. Its origin and pathogenesis can be explained as a developmental anomaly of the tracheobronchial buds from the primitive foregut. The patient was a 4-year-old boy with a child-fist-sized soft mass over his left scapula, which had been detected at birth and had been gradually growing. Grossly, it appeared to be a simple cyst with clear mucoid fluid. Histopathological study demonstrated a unilocular cyst composed of ciliated pseudostratified columnar epithelia, interspersed goblet cells, smooth muscles, and mucous glands on the cyst wall, which are features compatible with cutaneous bronchogenic cyst.

Microinjection of arginine vasopressin into the central nucleus of amygdala suppressed nociceptive jaw opening reflex in freely moving rats

This study was performed to examine the antinociceptive effect after microinjection of arginine vasopressin (AVP) into the central nucleus of amygdala. We recorded the jaw opening reflex in freely moving rats. After injection of 0.2 or 0.4 nM AVP into the central nucleus of amygdala, digastric electromyogram (dEMG) was suppressed to 55 +/- 5% or 88 +/- 3 of the control. Artificial cerebrospinal fluid had no effects on the basal dEMG activity. V(1) vasopressin receptor antagonist blocked the suppressive effect produced by microinjection of 0.4 nM AVP from 53 +/- 3 to 81 +/- 3% of the control. However, V(2) vasopressin receptor antagonist did not affect changes in dEMG. We observed dEMG activity after intracerebroventricular injection of naloxone, methysergide, or phentolamine. All drugs did not affect the basal dEMG activity at our dose. Naloxone blocked the suppressive effect of 0.4 nM AVP from 42 +/- 4 to 79 +/- 5% of the control. Methysergide also inhibited the suppression of dEMG from 44 +/- 3 to 83 +/- 6% of the control. However, phentolamine, an alpha-adrenergic receptor antagonist, did not affect the suppression of dEMG. These results indicate AVP in the central nucleus of amygdala has potent analgesic effects in the orofacial area. The antinociception of central AVP seems to be mediated by opioid and serotonergic pathways.

Smoking initiation and cessation in Norway and the United States: a comparison of two cross-sectional surveys

PURPOSE

Smoking prevalence in a population is affected by the proportion of adolescents who start to smoke, and the proportion of smokers who quit. Smoking prevalence has declined linearly in the US and in the state of California during the last 2 decades. Due to an increase in female smoking, the Norwegian smoking prevalence has been stable at around 35% since 1980, while other European countries have seen reductions of at least 10 percentage points.

METHODS

We compared data from two cross-sectional studies; one from Western and Central Norway (n = 5014), and one from Northern California (Stanford Five-City Project) (n = 2189).

RESULTS

Norwegian smoking prevalence figures were significantly higher in all age-sex groups younger than 60 years. The proportion of former smokers was not different, suggesting that the differences between the samples are due to higher smoking initiation in Norway. University education was the most potent covariate of both ever-smoking and current smoking across samples and gender. Amount of physical exercise was associated with never-smoking in Norway, but not in the US. Having smoking parents was related to ever-smoking in women but not in men in both samples. Smoking parents also was related to current smoking in Norway but not in the US.

IMPLICATIONS

Norway should increase efforts to prevent smoking initiation among adolescents, and especially among girls.

Pathways by which SES and ethnicity influence cardiovascular disease risk factors

Little is known about pathways by which socioeconomic status (SES) translates into individual differences in cardiovascular disease (CVD) risk factors. Because the socioeconomic structure is not the same for all ethnic subgroups, the pathways that lead to the development of CVD risk factors may vary by both SES and ethnicity. We used data from a large national survey to examine the independent associations of two indicators of SES (education and income) and ethnicity with six primary CVD risk factors. We then used data on smoking that reflected a temporal sequence to examine the extent to which SES and ethnicity influenced smoking at three different time points, from smoking onset, to a serious quit attempt, to successful quitting. These analyses provide an understanding of the relationships between SES, ethnicity, and CVD risk factors and suggest that if the timing, focus, and content of intervention programs take pathways into account they will result in more successful outcomes.

Central-amygdaloid carbachol suppressed nociceptive jaw opening reflex in freely moving rats

1. Experiments were carried out in rats with stimulating electrodes implanted in the dental pulp, recording electrodes inserted into the anterior digastric muscle, and indwelling cannula implanted in the central amygdaloid nucleus and the cisterna magna area. 2. Injection of 4.4 nM and 8.8 nM carbachol into the central amygdaloid nucleus suppressed digastric electromyogram (dEMG) to 81 +/- 8% and 47 +/- 9% of the control, respectively. 3. Atropine, a muscarinic receptor antagonist, blocked the suppression of dEMG in response to the administration of 8.8 nM carbachol into the amygdala. However, a mecamylamine, a nicotinic receptor antagonist, did not affect changes in dEMG. 4. Intracisternal naloxone, an opioid receptor antagonist, reduced the suppression of dEMG from 47 +/- 10 to 72 +/- 12% of the control. 5. Intracisternal methysergide, a serotonin receptor antagonist, also reduced the suppression of dEMG from 50 +/- 9 to 78 +/- 9% of the control. 6. The carbachol-induced antinociception from the central amygdaloid nucleus was attributed to opioid and serotonergic descending inhibitory influences on nociceptive pathways.

The effects of marital transitions on changes in physical activity: results from a 10-year community study

The potential effects of making a marital transition on subsequent physical activity were evaluated across a ten-year period in a population-based sample of 302 women and 256 men ages 25 to 75 years. Subjects completed a structured interview at five timepoints throughout the ten-year period during which they reported on their physical activity level as well as marital status. The transition from a married to a single state did not affect physical activity relative to remaining married when analyses of either slopes or mean values were used. In contrast, the transition from a single to a married state resulted in significant positive changes in physical activity relative to remaining single throughout the study period when physical activity slopes, though not means, were compared. The results suggest that marriage may potentially set the stage for natural changes in physical activity that could be capitalized on through appropriate intervention, but additional research is needed to verify this in light of the inconsistent pattern of findings.

Determinants of cholesterol screening and treatment patterns. Insights for decision-makers

BACKGROUND

Adult cholesterol screening and treatment policies by the National Cholesterol Education Program recommend that physicians screen all adults aged > 20 [corrected]. On the other hand, the American College of Physicians recommends that healthy young adult men aged > 35 and premenopausal women aged > 45 not be screened due to concerns about the cost of and health risks associated with overuse of pharmacologic therapy in lieu of lifestyle modification.

OBJECTIVES

The objectives of this study were to determine the type of treatment (lifestyle vs. pharmacologic) that physicians actually prescribe for individuals screened for elevated cholesterol.

METHODS

Self-report data were derived from the 1989-1990 cross-sectional survey of the Stanford Five-City Project on 1,883 Latino and Anglo men and women aged 20 to 74 years of age. A four-stage sequential design was conducted using multiple stepwise regression analyses with a significance cutpoint of P < .01.

RESULTS

Young adult men and women were significantly less likely to report ever having been screened (OR 1.02; 95% CI 1.07-1.09). Individuals of low socioeconomic status (SES) were also significantly less likely to report ever being screened (OR, 1.12; CI, 1.08-1.16), as were Latino men and women, regardless of age (OR 1.57; CI, 1.14-2.18). There were no significant differences in the pattern of physician care utilization among low SES or Latino individuals during the previous 12-month period. Among those under physician care to lower cholesterol, young adults were more likely to be prescribed lifestyle modification (OR, 0.95; CI, 0.92-0.98).

CONCLUSIONS

Our results suggest that although young adults are less likely to be screened, if screened they are more likely to be prescribed lifestyle modification than pharmacologic treatment for elevated cholesterol. The lower prevalence of screening among low SES and Latino individuals suggests the need for policy discussions to reduce these disparities.

Ethnic and socioeconomic differences in cardiovascular disease risk factors: findings for women from the Third National Health and Nutrition Examination Survey, 1988-1994

CONTEXT

Cardiovascular disease (CVD) risk factors are higher among ethnic minority women than among white women in the United States. However, because ethnic minority women are disproportionately poor, socioeconomic status (SES) may substantially explain these risk factor differences.

OBJECTIVE

To determine whether differences in CVD risk factors by ethnicity could be attributed to differences in SES.

DESIGN

Third National Health and Nutrition Examination Survey conducted between 1988 and 1994.

SETTING

Eighty-nine mobile examination centers.

PARTICIPANTS

A total of 1762 black, 1481 Mexican American, and 2023 white women, aged 25 to 64 years, who completed both the home questionnaire and medical examination.

MAIN OUTCOME MEASURES

Ethnicity and years of education (SES) in relation to systolic blood pressure, cigarette smoking, body mass index (BMI, a measure of weight in kilograms divided by the square of height in meters), physical inactivity, non-high-density lipoprotein cholesterol (non-HDL-C [the difference between total cholesterol and HDL-C]), and non-insulin-dependent diabetes mellitus.

RESULTS

As expected, most CVD risk factors were higher among ethnic minority women than among white women. After adjusting for years of education, highly significant differences in blood pressure, BMI, physical inactivity, and diabetes remained for both black and Mexican American women compared with white women (P<.001). In addition, women of lower SES from each of the 3 ethnic groups had significantly higher prevalences of smoking and physical inactivity and higher levels of BMI and non-HDL-C than women of higher SES (P<.001).

CONCLUSIONS

These findings provide the greatest evidence to date of higher CVD risk factors among black and Mexican American women than among white women of comparable SES. The striking differences by both ethnicity and SES underscore the critical need to improve screening, early detection, and treatment of CVD-related conditions for black and Mexican American women, as well as for women of lower SES in all ethnic groups.

Central NO is involved in the antinociceptive action of intracisternal antidepressants in freely moving rats

The present study was performed to examine the central effects of antidepressants on nociceptive jaw opening reflex after intracisternal injection. we also investigated the mechanisms of central antinociceptive action of intracisternal antidepressants. We recorded the jaw opening reflex in freely moving rats and chose to administer antidepressants intracisternally in order to eliminate the effects of anesthetic agents on the pain assessment and evaluate the importance of the spinal site of action of antidepressants. After intracisternal injection of 15 microg imipramine, digastric electromyogram (dEMG) was decreased to 76+/-6% of the control. Intracisternal administration of 30 microg desipramine, nortriptyline or imipramine suppressed dEMG remarkably to 48+/-2, 27+/-8, or 25+/-5% of the control, respectively. The suppression of dEMG was maintained for 50 min. L-NG-Nitroarginine methyl ester (NAME) blocked the suppression of dEMG from 32+/-2 to 81+/-5% of the control. These results indicate that antidepressants produce antinociception through central mechanisms in the orofacial area. The central NO pathway seems to be involved in the antinociception of intracisternal antidepressants at supraspinal sites.