Oral maxillofacial surgeons and Orthodontists' perceptions about anterior inferior crowding and indications of mandibular third molar extraction.

BACKGROUND: There are still many doubts about anterior inferior crowding and indications of mandibular third molar extraction, although it is very studied subject in the literature. The aim of this study was to evaluate the perceptions of oral maxillofacial surgeons (OMFSs) and orthodontists about anterior inferior crowding and indications of mandibular third molar extraction. MATERIAL AND METHODS: A web-based survey was developed and sent to professionals in order to collect their opinion about the fact that third lower molars cause crowding and questions about the indication of third molars for orthodontic treatment. Descriptive analysis was performed and Chi-square or G tests were applied with a 95% confidence interval. RESULTS: The study included a total of 218 participants, of whom 115 were OMFSs and 103 were orthodontists. The results showed that 56.5% of OMFSs and 35.0% of orthodontists believe that the lower third molars cause anterior inferior crowding (p<0.001). A total of 91.3% of OMFSs and 70.9% of orthodontists indicate the extraction of lower third molars to aid orthodontic treatment (p<0.001). CONCLUSIONS: It can be concluded that in being an oral maxillofacial surgeon, a higher odds ratio is observed to consider that lower third molars cause dental crowding compared to those who are orthodontist. The indication of exodontia of lower third molars for orthodontic treatment was more frequent among OMFSs when compared to orthodontists.

Macro- and microstructural descriptions of the zebrafish (Danio rerio) liver.

The liver is an essential metabolically active organ, responsible for many vital life functions such as metabolism, synthesis, and storage. This study describes the macroscopic and microscopic zebrafish liver and its temporal changes during a period of 13 weeks. Forty-six adult zebrafish were used (46), of which 27 were females and were 19 males. Seven fish were euthanized initially for macroscopic evaluation and 3 fish were euthanized weekly for 13 weeks for microscopic evaluation. Routine histological technique was performed; the slides were stained with haematoxylin/eosin and periodic acid-Schiff. The volumetric (Vv(h)) and numerical (Nv(h)) densities of hepatocytes and vacuolation intensity were determined weekly. The liver was located in the coelomic cavity ventrally to the swim bladder, slightly brownish and divided into 3 hepatic lobes. Microscopically, it consisted of hepatocytes forming a muralium duplex around the sinusoids. The staining of the cytoplasm of hepatocytes was more eosinophilic and more basophilic in males and females, respectively. There was no formation of portal triads and phagocytic cells. The gallbladder had transitional epithelium, and the bile ducts had simple cuboidal epithelium. The volume and numerical density of hepatocytes during the 13 weeks was not statistically different, but these parameters displayed a positive correlation. The vacuolation was due to the presence of glycogen. The zebrafish liver has macro and micro structural particular features while, quantitatively, the volume and number of hepatocytes showed great capacity to respond to the physiological needs of the animal at the time.

Genetic control of the number of leaves above the ear in maize.

In this study, we examined the genetic control of the number of leaves above the first ear in maize. The F2 generations and the backcrosses were obtained from 2 contrasting lines for this trait. All generations were assessed in a completely randomized block design with 2 replications. The number of leaves above the ear was counted when the plants were in the tasseling stage at the level of plants per plot. Mean and variance components were estimated using the weighted least square method. We observed a predominance of non-additive effects in the genetic control of number of leaves above the ear. These results indicate that this trait shows high heritability.

Transcranial direct current stimulation and exercises for treatment of chronic temporomandibular disorders: a blind randomised-controlled trial.

To evaluate the effect of adding transcranial direct current stimulation (tDCS) to exercises for chronic pain, dysfunction and quality of life in subjects with temporomandibular disorders (TMD). Participants were selected based on the RDC/TMD criteria and assessed for pain intensity, pressure pain threshold over temporomandibular joint and cervical muscles and quality of life. After initial assessment, all individuals underwent a 4-week protocol of exercises and manual therapy, together with active or sham primary motor cortex tDCS. Stimulation was delivered through sponge electrodes, with 2 mA amplitude, for 20 min daily, over the first 5 days of the trial. A total of 32 subjects (mean age 24.7 ± 6.8 years) participated in the evaluations and treatment protocol. Mean pain intensity pre-treatment was 5.5 ± 1.4 for active tDCS group, and 6.3 ± 1.2 for sham tDCS. Both groups showed a decrease in pain intensity scores during the trial period (time factor--F(4.5,137.5) = 28.7, P < 0.001; group factor--F(1.0,30.0 = 7.7), P < 0.05). However, there were no differences between the groups regarding change in pain intensity (time*group interaction--F(4.5,137.5) = 1.5, P = 0.137). This result remained the same after 5 months (t-test t = 0.29, P > 0.05). Pressure pain thresholds decrease and improvement in quality of life were also noticeable in both groups, but again without significant differences between them. Absolute benefit increase was 37.5% (CI 95%: -15.9% to 90.9%), and number needed to treat was 2.66. This study suggests that there is no additional benefit in adding tDCS to exercises for the treatment of chronic TMD in young adults.

Cone beam computed tomography (CBCT) referrals in paediatric patients: A 24-month retrospective study in two radiological centers in Campinas, Brazil.

PURPOSE: To evaluate the CBCT referrals in paediatric patients over a 24-month period. METHODS: A retrospective study was conducted in two radiological centers in Campinas, Brazil. Patients were divided into three age groups: G1: age under 10 years, G2: age between 10 and 12 years, and G3: age over 12 years. The following data were collected: patients' age and sex, localisation, reasons for referral and dental specialty responsible for the request of CBCT exams. RESULTS: Data from 367 patients were assessed. CBCT was used more frequently in the Group 3 (58.9%). There was significant association between the region of the exam and age group (P < 0.05), with a higher percentage of exams in the maxilla for the age over 12 years (35.6%) than that of up to 10 years (50.9%) and between 10 and 12 years (51.1%). Alterations were observed in 79.3% of the exams and 47.4% showed impacted teeth with significant association with the increase in age group (P < 0.05). Of the total number of exams, (55.3%) were requested in Orthodontics followed by Oral Surgery (30.0%) and Paediatric Dentistry (9.5%). CONCLUSIONS: It can be concluded that CBCT exams were indicated frequently for the age over 12 years. The presence of impacted teeth represented the main reason for referrals and Orthodontics was the dental specialty that indicated CBCT with higher frequency.

Evaluating pain, fear, anxiety or stress/distress using children's drawings in paediatric dentistry: a scoping review.

PURPOSE: The aim of this study was to systematically review the literature to answer the question: Can children's drawings represent a helping tool so the dentist can better understand the children's pain, fear, anxiety or stress/distress and their perception concerning the dentist and/or dental treatment? METHODS: A scoping review was done. Cochrane Library, EMBASE, LILACS, LIVIVO, PsycINFO, PubMed, Scopus, Web of Science, and Grey literature was searched. Cross-sectional, quasi-experimental and qualitative studies in which patients were children and adolescents were included. Two authors independently selected studies to extract data and evaluate methodological quality by using Joanna Briggs Institute tools. Data collected included: characteristics of the studies, drawing evaluation/scales, main results and conclusion. RESULTS: Out of 1037 papers were identified in search, 25 studies verified the emotional state and the children's perceptions regarding dental environment and the dentist and were included in the narrative synthesis. The spontaneous drawings were useful to identify the children's emotions. Drawings might be considered a helping tool to identify children and adolescents' perception in relation to dental treatment. Few studies used validated instruments. There were methodological disparities among studies. CONCLUSIONS: The drawings can be considered a useful tool in identifying children's pain, fear, anxiety or stress/distress and perceptions about the dentist and/or dental treatment. Future studies with standardized analysis of the drawings are recommended. Code https://doi.org/10.17605/OSF.IO/U5BJH . "Retrospectively registered".

Molar-incisor hypomineralization: parent's and children's impact perceptions on the oral health-related quality of life.

PURPOSE: To evaluate the perception of parents and children and the impact of molar and incisor hypomineralization (MIH) on the oral health-related quality of life (OHRQoL). METHODS: A cross-sectional study was conducted with a group of 253 children aged 6-12 years presenting MIH and their parents or guardians who initially answered an interview containing socioeconomic and demographic questions as well as the Parental-Caregiver's Perceptions Questionnaire (P-CPQ). The children answered the Child Perceptions Questionnaire (CPQ8-10) and Child Perceptions Questionnaire (CPQ11-14) and the clinical evaluation of MIH was performed. Poisson regression with robust variance was used in the data analysis. RESULTS: The parent's perception showed that the impact felt by the children regarding caries leads to a higher oral symptom impact, functional limitation, emotional well-being and total PCPQ score domains, as well. For children with severe MIH, a higher prevalence of impact was felt regarding the functional limitation and emotional well-being. For CPQ8-10, the oral symptoms domain presented the highest mean score, while CPQ11-14 showed the functional limitations domain and P-CPQ the emotional well-being domain. CONCLUSION: Considering the perception of parents or guardians, it was concluded that MIH promotes a negative impact on the OHRQoL. MIH had no significant impact on OHRQoL according to children's perceptions.

Salt fluoridation: a meta-analysis of its efficacy for caries prevention.

UNLABELLED: The aim of this meta-analysis was to assess the caries preventive effect of Salt fluoridation (SF) in the permanent dentition in children. THE OBJECTIVES WERE TO COMPARE: (1) the caries preventive effects of SF versus no exposure in different age cohorts (6-8; 9-12; and 13-15 years old); (2) SF versus other community based interventions (milk or water fluoridation [WF]). METHODS: 9 English and 2 non-English databases were searched for papers that reported on the caries preventive effect of groups (with controls) that were exposed to SF in the form of mean DMFT scores with standard deviations. Differences in exposed and nonexposed groups were computed on the basis of weighted mean differences (WMDs) with 95% confidence intervals (CIs). RESULTS: For 6-8 year olds, the pooled reduction in DMFT scores was -0.98 [95% CI: -1.68 to -0.29]; for 9-12 year olds, it was -2.13 [95% CI: -2.55 to -1.70] and for the 13-15 year old groups, -4.22 [95% CI: -6.84 to -1.55]. All the analyses favoured the SF groups (p <0.001). For SF versus WF, there was no difference (-0.11 reduction [95% CI: -0.29 to +0.07]). CONCLUSION: Within limitations, the pooled estimates of the WMDs for the different age cohorts favoured SF versus no exposure.

Feasibility of the International Caries Detection and Assessment System (ICDAS-II) in epidemiological surveys and comparability with standard World Health Organization criteria.

This study evaluated the feasibility of using the International Caries Detection and Assessment System (ICDAS-II) in epidemiological surveys and compared ICDAS with WHO criteria. Two hundred and fifty-two children (36-59 months old) in Amparo, Brazil, were each examined by 2 examiners using ICDAS-II or WHO criteria. Dmf-t, dmf-s, caries prevalence and examination time were calculated using both systems. ICDAS-II was comparable to standard criteria when the cut-off point was score 3. Examination by ICDAS-II took twice as long as by WHO criteria. In conclusion, ICDAS-II, besides providing information on non-cavitated caries lesions, can generate data comparable to previous surveys which used WHO criteria.

Absence of carious lesions at margins of glass-ionomer and amalgam restorations: a meta- analysis.

AIM: To report on the absence of carious lesions at margins of glass ionomer cement (GIC) and amalgam restorations. METHODS: Six Anglophone and 1 Lusophone databases were searched for articles up to 5 January 2008. Inclusion criteria for articles were: (i) titles/abstracts relevant to topic; (ii) published in English, Portuguese or Spanish language; (iii) reporting on a randomised control trial. Exclusion criteria were: (i) insufficient random allocation of study subjects (ii) operator and subject not blinded, where appropriate; (iii) not all entered subjects accounted for at trial conclusion; (iv) subjects of both groups not followed up the same way. Articles were accepted only if they complied with all the criteria. Ten articles complied with the inclusion criteria and were selected for review. From these 4 were rejected and 6 articles reporting on 8 separate studies accepted. Due to aspects of heterogeneity, studies were sub-grouped before meta- analysis. RESULTS: Significantly less carious lesions were observed on single-surface GIC restorations in permanent teeth after 6 years as compared to restorations with amalgam (OR 2.64 - CI 95% 1.39 - 5.03, p= 0.003). No studies investigating multiple-surface restorations on permanent teeth were identified. Studies investigating carious lesions at margins of restorations in primary teeth showed no difference between both materials after 3 and 8 years. CONCLUSIONS: Carious lesions at margins of single-surface GIC restorations are less common than with amalgam fillings after 6 years in permanent teeth. No difference was observed in primary teeth. More trials are needed in order to confirm these results.

Opioid activation in the lateral parabrachial nucleus induces hypertonic sodium intake.

Opioid mechanisms are involved in the control of water and NaCl intake and opioid receptors are present in the lateral parabrachial nucleus (LPBN), a site of important inhibitory mechanisms related to the control of sodium appetite. Therefore, in the present study we investigated the effects of opioid receptor activation in the LPBN on 0.3 M NaCl and water intake in rats. Male Holtzman rats with stainless steel cannulas implanted bilaterally in the LPBN were used. In normohydrated and satiated rats, bilateral injections of the opioid receptor agonist beta-endorphin (2 nmol/0.2 microl) into the LPBN induced 0.3 M NaCl (17.8+/-5.9 vs. saline: 0.9+/-0.5 ml/240 min) and water intake (11.4+/-3.0 vs. saline: 1.0+/-0.4 ml/240 min) in a two-bottle test. Bilateral injections of the opioid antagonist naloxone (100 nmol/0.2 microl) into the LPBN abolished sodium and water intake induced by beta-endorphin into the LPBN and also reduced 0.3 M NaCl intake (12.8+/-1.5 vs. vehicle: 22.4+/-3.1 ml/180 min) induced by 24 h of sodium depletion (produced by the treatment with the diuretic furosemide s.c.+sodium deficient food for 24 h). Bilateral injections of beta-endorphin into the LPBN in satiated rats produced no effect on water or 2% sucrose intake when water alone or simultaneously with 2% sucrose was offered to the animals. The results show that opioid receptor activation in the LPBN induces hypertonic sodium intake in satiated and normohydrated rats, an effect not due to general ingestive behavior facilitation. In addition, sodium depletion induced 0.3 M NaCl intake also partially depends on opioid receptor activation in the LPBN. The results suggest that deactivation of inhibitory mechanisms by opioid receptor activation in the LPBN releases sodium intake if excitatory signals were activated (sodium depletion) or not.

Evaluation of knowledge of students in paediatric dentistry concerning cardiopulmonary resuscitation skills in children.

AIM: The study evaluated the theoretical knowledge and practical ability of students in paediatric dentistry concerning basic life support (BLS) and cardiopulmonary resuscitation (CPR) in children and babies. METHODS: Seventy paediatric dentistry students answered a questionnaire and also performed a simulation of the manoeuvres of BLS and CPR on baby and child manikins. RESULTS: The results showed that 41 (58%) students had never received BLS training. When questioned about the correct ratio of compression and ventilation during CPR, most students answered incorrectly. For the CPR of babies in the presence of a first responder only 19 (27.1%) answered correctly (30 × 2), and for babies with two rescuers, 23 (32.8%) answered correctly (15 × 2); in relation to the correct rhythm of chest compressions, 38 (54.4%) answered incorrectly; when asked if they felt prepared to deal with a medical emergency in their dental surgeries, only 12 (17.1%) stated "yes". In the practice evaluation, 51 (73%) students who had been assessed in CPR manoeuvres for children and 55 (78%) in the manoeuvres for babies scored inadequately. CONCLUSIONS: The evaluated students did not have adequate knowledge about CPR in children and babies.

Gender identity in patients with 5-alpha reductase deficiency raised as females.

BACKGROUND AND OBJECTIVE: 5-Alpha reductase type 2 deficiency (5-ARD) is a rare disorder of sex development. The lack of 5-alpha reductase, an enzyme that converts testosterone into dihydrotestosterone, results in external genitalia that may appear female, or predominantly male, albeit undervirilized, or, more often, ambiguous. METHODS: This study describes a series of patients with 5-ARD raised as female, focusing on aspects related to gender identity. Following a retrospective chart review, patients with 5-ARD were invited to return to the clinic to enable their gender identity to be assessed using an 11-item structured in-house questionnaire. The Golombok-Rust Inventory of Sexual Satisfaction was applied to patients who had initiated their sexual life. RESULTS: Six patients aged >15 years with 5-ARD and raised as female were included. Most patients were diagnosed late: two before and four after puberty. The mean length of the phallus was 2.8 cm (0.5-5.0). Reasons for seeing a doctor included genital appearance (n = 3), amenorrhea/absence of breast development (n = 2), and changes in gender role attitudes (n = 1). According to the gender identity assessment, 4 patients identified as female, 1 as male, and 1 as both genders. Only the patient identified as male requested gender re-assignment. Of the two patients who had initiated their sexual life, sexual satisfaction was found to be good in one and poor in the other due to vaginal discomfort during intercourse. CONCLUSION: In the present series, the majority of undervirilized patients with a diagnosis of 5-ARD raised as female were in complete conformation with being female and described themselves as heterosexual. The more virilized patients were those least in conformity with their female-assigned gender.

Detection and Molecular Characterization of Yellow Fever Virus, 2017, Brazil.

At the end of 2016, Brazil experienced an unprecedented yellow fever (YF) outbreak. Clinical, molecular and ecological aspects of human and non-human primate (NHP) samples collected at the beginning of the outbreak are described in this study. Spatial distribution analyses demonstrated a strong overlap between human and NHP cases. Through molecular analyses, we showed that the outbreak had a sylvatic origin, caused by the South American genotype 1 YFV, which has already been shown to circulate in Brazil. As expected, the clusters of cases were identified in regions with a low vaccination coverage. Our findings highlight the importance of the synchronization of animal surveillance and health services to identify emerging YF cases, thereby promoting a better response to the vulnerable population.

GABA(A) receptor activation in the lateral parabrachial nucleus induces water and hypertonic NaCl intake.

Inhibitory serotonergic and cholecystokinergic mechanisms in the lateral parabrachial nucleus and central GABAergic mechanisms are involved in the regulation of water and NaCl intake. In the present study we investigated if the GABA(A) receptors in the lateral parabrachial nucleus are involved in the control of water, NaCl and food intake in rats. Male Holtzman rats with stainless steel cannulas implanted bilaterally into the lateral parabrachial nucleus were used. Bilateral injections of muscimol (0.2 nmol/0.2 microl) into the lateral parabrachial nucleus strongly increased 0.3 M NaCl (20.3+/-7.2 vs. saline: 2.6+/-0.9 ml/180 min) without changing water intake induced by the treatment with the diuretic furosemide combined with low dose of the angiotensin converting enzyme inhibitor captopril s.c. In euhydrated and satiated rats, bilateral lateral parabrachial nucleus injections of muscimol (0.2 and 0.5 nmol/0.2 microl) induced 0.3 M NaCl intake (12.1+/-6.5 and 32.5+/-7.3 ml/180 min, respectively, vs. saline: 0.4+/-0.2 ml/180 min) and water intake (5.2+/-2.0 and 7.6+/-2.8 ml/180 min, respectively, vs. saline: 0.8+/-0.4 ml/180 min), but no food intake (2+/-0.4 g/240 min vs. saline: 1+/-0.3 g/240 min). Bilateral lateral parabrachial nucleus injections of the GABA(A) antagonist bicuculline (1.6 nmol/0.2 microl) abolished the effects of muscimol (0.5 nmol/0.2 microl) on 0.3 M NaCl and water intake. Muscimol (0.5 nmol/0.2 microl) into the lateral parabrachial nucleus also induced a slight ingestion of water (4.2+/-1.6 ml/240 min vs. saline: 1.1+/-0.3 ml/240 min) when only water was available, a long lasting (for at least 2 h) increase on mean arterial pressure (14+/-4 mm Hg, vs. saline: -1+/-1 mm Hg) and only a tendency to increase urinary volume and Na+ and K+ renal excretion. Therefore the activation of GABA(A) receptors in the lateral parabrachial nucleus induces strong NaCl intake, a small ingestion of water and pressor responses, without changes on food intake.

Predictors of body appearance cognitive distraction during sexual activity in a sample of men with ED.

Our aim is to scrutinize the extent to which aspects of body dissatisfaction and relationship variables predict body appearance cognitive distraction during sexual activity (BACDSA) in a sample of men diagnosed with ED. A total of 65 heterosexual Portuguese participants with ED completed a survey that included questions on socio-demographic data as well as body-related and relationship measures. We used the Global Body Dissatisfaction (GBD) Subscale of the Body Attitudes Test; a version of the Contour Drawing Rating Scale; a single item on partner's opinion perceived about one's body appearance; the Global Measure of Relationship Satisfaction; and the Inclusion of Other in Self Scale. Open questions assessed focus on specific body parts during sexual activity and relationship length. Hierarchical multiple regression indicated that only GBD was a significant predictor of BACDSA, contrary to the relationship measures that showed no significant predictive effect (R(2) =0.47). Our results support the important role of individual factors on explanatory models of sexual dysfunctions, suggesting that interventions addressing individual factors that affect BACDSA may be of preference.

Evidence of pulpotomy in primary teeth comparing MTA, calcium hydroxide, ferric sulphate, and electrosurgery with formocresol.

AIM: The aim of this study was to evaluate the scientific evidence of pulpotomy in primary teeth comparing mineral troxide aggregate (MTA), calcium hydroxide, ferric sulphate, and electrosurgery with formocresol. METHODS: A systematic search using key words was conducted using seven databases up to December 10, 2013. Clinical articles in English, Portuguese and Spanish were selected, which were in accordance with the inclusion and exclusion criteria and the research objective of comparing whether pulpotomy performed with formocresol in primary teeth is more effective than other medicaments or techniques. RESULTS: Out of the 12,515 publication initially identified, 30 clinical articles were included in the systematic review and analysed by four meta-analyses. The success rate of MTA (94.6 %) was higher than that of formocresol (87.4 %), with a statistically significant difference (OR = 0.39; 95 % CI = 0.25-0.62). Formocresol pulpotomy success was not statistically different from ferric sulphate or electrosurgery. CONCLUSION: MTA was clinically and radiographically superior to formocresol for pulpotomy of primary teeth. The other alternatives to formocresol such as electrosurgery and ferric sulphate can be used instead of formocresol since they showed success similar to formocresol. In addition, there is no evidence to support calcium hydroxide for pulpotomies in primary teeth.

Gabaergic and opioid receptors mediate the facilitation of NaCl intake induced by α2-adrenergic activation in the lateral parabrachial nucleus.

Alpha2-adrenergic, gabaergic or opioidergic activation in the lateral parabrachial nucleus (LPBN) increases sodium intake. In the present study, we investigated the effects of single or combined blockade of opioidergic and gabaergic receptors in the LPBN on the increase of 0.3M NaCl intake induced by α2-adrenoceptor activation in the LPBN. Male Holtzman rats (n=5-9/group) with cannulas implanted bilaterally in the LPBN were treated with the diuretic furosemide (10 mg/kg b wt.) combined with low dose of the angiotensin converting enzyme inhibitor captopril (5 mg/kg b wt.) subcutaneously. Bilateral injections of moxonidine (alpha2-adrenergic/imidazoline receptor agonist, 0.5 nmol) into the LPBN increased furosemide+captopril-induced 0.3M NaCl intake (25.8±1.4, vs. vehicle: 3.8±1.1 ml/60 min). The opioidergic receptor antagonist naloxone (100 nmol) or the GABAA receptor antagonist bicuculline (5 nmol) injected into the LPBN partially reduced the increase of 0.3M NaCl intake produced by LPBN moxonidine (11.8±4.0 and 22.8±4.5, respectively, vs. vehicle+moxonidine: 31.6±4.0 ml/60 min, respectively). Similar to the treatment with each antagonist alone, the combined injections of naloxone (100 nmol) and bicuculline (5 nmol) into the LPBN also partially reduced moxonidine effects on 0.3M NaCl intake (15.5±6.5 ml/60 min). The GABAB receptor antagonist saclofen (5 nmol) injected into the LPBN did not change the effects of moxonidine on 0.3M NaCl intake (24.3±7.8 ml/120 min). These results suggest that the increase of 0.3M NaCl intake by α2-adrenergic receptor activation in the LPBN is partially dependent on GABAA and opioid receptor activation in this area.

Noradrenaline and mixed alpha 2-adrenoceptor/imidazoline-receptor ligands: effects on sodium intake.

The effect of noradrenaline, and mixed ligands to alpha 2-adrenoceptors (alpha 2-AR) and imidazoline receptors (IR), injected intracerebroventricularly (i.c.v.), on sodium intake of sodium depleted rats, was tested against idazoxan, a mixed antagonist ligand to alpha 2-AR and IR. The inhibition of sodium intake induced by noradrenaline (80 nmol) was completely reversed by idazoxan (160 and 320 nmol) injected i.c.v. The inhibition of sodium intake induced by mixed ligands to alpha 2-AR and IR, UK14,304, guanabenz and moxonidine, was antagonized from 50 to 60% by idazoxan i.c.v. The results demonstrate that noradrenaline, a non-ligand for IR, acts on alpha 2-AR inhibiting sodium intake. The possibility that either alpha 2-AR or IR mediate the effect of mixed agonists on sodium intake remains an open question.

Early loss of synaptic protein PSD-95 from rod terminals of rhodopsin P347L transgenic porcine retina.

Retinitis pigmentosa (RP), a type of retinal degeneration involving first rod and then slow cone photoreceptor degeneration, can be caused by any of a number of mutations in different genes. In the cases of mutations affecting rod-specific genes such as rhodopsin, it is unclear how the mutations may cause degeneration of cones. We have used the porcine retina, which is rod-dominated and has an abundance of cones, to study the mutation-induced changes in both rod and cone photoreceptors. Like patients with the same mutation, rhodopsin P347L transgenic swine manifest rod-cone degeneration. In addition, the rod bipolar cells fail to form synaptic connections with rods; instead, they form ectopic synapses with cones. The mechanisms that prevent the formation of the rod-rod bipolar cell synaptic connection are not known. We used specific antibodies and immunocytochemistry to show that the synaptic protein, PSD-95, is present in both normal and transgenic porcine retinas. During neonatal development, however, PSD-95 is lost from rod terminals in the transgenic swine. This loss is virtually complete (90%) by postnatal day 5, at a time when greater than 80% of rod cell bodies still remain. Furthermore, the remaining rods retain their outer segments and their gross morphology appears relatively normal. In contrast, PSD-95 expression continues in cone terminals, even in 10-month-old transgenic swine, where the rods have all disappeared and the cones show signs of severe degeneration. These results suggest that loss of PSD-95 may not be a general consequence of the deteriorating cell. Rather, the very early and selective loss of PSD-95 from the rod terminals may be causally related to the absence of rod-rod bipolar cell synapses in the rhodopsin P347L transgenic retina.