EFFECT OF A NOVEL ESSENTIAL OIL MOUTHRINSE WITHOUT ALCOHOL ON GINGIVITIS: A DOUBLE-BLINDED RANDOMIZED CONTROLLED TRIAL

Several different plant extracts have been evaluated with respect to their antimicrobial effects against oral pathogens and for reduction of gingivitis. Given that a large number of these substances have been associated with significant side effects that contraindicate their long-term use, new compounds need to be tested. The aim of this study was to assess the short-term safety and efficacy of a Lippia sidoides ("alecrim pimenta")-based essential oil mouthrinse on gingival inflammation and bacterial plaque. Fifty-five patients were enrolled into a pilot, double-blinded, randomized, parallel-armed study. Patients were randomly assigned to undergo a 7-day treatment regimen with either the L. sidoides-based mouthrinse or 0.12% chlorhexidine mouthrinse. The results demonstrated decreased plaque index, gingival index and gingival bleeding index scores at 7 days, as compared to baseline. There was no statistically significance difference (p>0.05) between test and control groups for any of the clinical parameters assessed throughout the study. Adverse events were mild and transient. The findings of this study demonstrated that the L. sidoides-based mouthrinse was safe and efficacious in reducing bacterial plaque and gingival inflammation.     

Effects of Experimental Lead Exposure on Testis of the Chestnut Capped Blackbird <Emphasis Type="Italic">Chrysomus ruficapillus</Emphasis>

Lead (Pb) effects on testis histology, as well as sperm quality and oxidative status were evaluated in male Chestnut Capped Blackbird (Chrysomus ruficapillus). Wild blackbirds were captured, immediately sampled (field group) or kept in captivity and treated with a single intraperitoneal injection of saline solution (control) or saline solution with Pb acetate (50 or 100 mg/kg Pb). Seven days after injection, whole blood, ductus deferens and testis samples were collected. Increased Pb concentrations were observed in whole blood and testis of Pb-exposed blackbirds with respect to those from field and control blackbirds. Sperm cells of Pb-exposed blackbirds showed loss of membrane integrity, mitochondrial functionality, and DNA integrity. Also, oxidative damage was observed in testis of blackbirds injected with 100 mg/kg Pb. These findings indicate that Pb is accumulated in testis of C. ruficapillus, inducing severe morphological and biochemical injury that can compromise the reproductive performance of male blackbirds. Although the exposure scenario (Pb acetate, high dosage and intraperitoneal injection) tested in the present study would likely not occur in the wild, it was adequate to show potential and relevant toxic effects of Pb in wild birds.     

Sex-specific effects of isolation stress and consumption of palatable diet during the prepubertal period on metabolic parameters

Objectives

Social isolation during the prepubertal period may have long-term effects on metabolism. The exposure to stressful events is associated with increased palatable food intake, constituting reward-based eating. However, palatable food consumption in early life may lead to metabolic alterations later in life. We investigated whether isolation stress during early life can lead to metabolic alterations in male and female rats with or without exposure to a palatable diet.

Methods

Animals were stressed by isolation during one week after weaning, with or without exposure to a palatable diet.

Results

Stress and palatable diet induced increased caloric consumption. In females, there was a potentiation of consumption in animals exposed to stress and palatable diet, reflected by increased weight gain and triacylglycerol levels in juveniles, as well as increased adiponectin levels. Most of the effects had disappeared in the adults. Different effects were observed in males: in juveniles, stress increased unacylated ghrelin levels, and hypothalamic neuropeptide Y (NPY). Subsequently, adult males that were exposed to a palatable diet during prepuberty showed increased body weight and retroperitoneal fat deposition, increased glycemia, and decreased plasma adiponectin and hypothalamic NPY. Exposure to stress during prepuberty led to increased adrenals during adulthood, decreased LDL-cholesterol and increased triacylglycerol levels.

Conclusion

Isolation stress and consumption of palatable diet changes metabolism in a sex-specific manner. Prepuberty female rats were more prone to stress effects on food consumption, while males showed more long-lasting effects, being more susceptible to a metabolic programming after the consumption of a palatable diet.     

Effects of blockade of central dopamine D1 and D2 receptors on thermoregulation,metabolic rate and running performance

To assess the effects of a blockade of central D₁- and D₂-dopaminergic receptors on metabolic rate, heat balance and running performance, 10 nmol (2 μl) of a solution of the D₁ antagonist SCH-23390 hydrochloride (SCH,n= 6), D₂ antagonist eticlopride hydrochloride (Eti, n = 6), or 2 μl of 0.15 MNaCl (SAL, n = 6) was injected intracerebroventricularly into Wistar rats before the animals began graded running until fatigue (starting at i0 m/min, increasing by 1 m/min increment every 3 min until fatigue, 5% inclination). Oxygen consumption and body temperature were recorded at rest, during exercise and following 30 min of recovery. Control experiments with injection of two doses (10 and 20 nmol/rat) of either SCH or Eti solution were carried out in resting rats as well. Body heating rate, heat storage, workload and mechanical efficiency were calculated. Although SCH and Eti treatments did not induce thermal effects in resting animals, they markedly reduced running performance (–83%, SCH; -59% Eti, p < 0.05) and decreased maximal oxygen uptake (–79%, SCH; -45%, Eti, p < 0.05) in running rats. In addition, these treatments induced a higher body heating rate and persistent hyperthermia during the recovery period. Our data demonstrate that the alteration in dopamine transmission induced by the central blockade of dopamine- D₁ and D₂ receptors impairs running performance by decreasing the tolerance to heat storage. This blockade also impairs the dissipation of exercise-induced heat and metabolic rate recovery during the post-exercise period. Our results provide evidence that central activation of either dopamine- Di or D₂ receptors is essential for heat balance and exercise performance.     

Persistent multifocal pseudo‐conduction blocks in vasculitic neuropathy without antiganglioside antibodies

A woman presented with severe multifocal acute axonal neuropathy due to necrotizing vasculitis. Six years later, electrophysiological examination revealed features suggestive of persistent conduction block (CB) with increased temporal dispersion (ITD) affecting the right median and tibial nerves. A clinical case characterized by multifocal CBs that were observed several years after an initial episode of vasculitic neuropathy was recently reported. The occurrence of CBs paralleled clinical deterioration and was attributed to superimposed antiganglioside antibody‐mediated demyelination. In contrast, our patient was clinically stable and did not have antiganglioside antibodies. Nerve conduction studies showed pseudo‐CBs rather than true CBs. We suggest that pseudo‐CBs with ITD can reveal heterogeneous axonal regeneration as a sequel of a severe multifocal vasculitic neuropathy. This condition should be distinguished from the occurrence of pseudo‐CB in the acute phase of vasculitis or from superimposed immune‐mediated demyelination. Muscle Nerve 40: 290–293, 2009     

Neonatal handling affects learning, reversal learning and antioxidant enzymes activities in a sex-specific manner in rats

Early life experiences have profound influences on behavior and neurochemical parameters in adult life. The aim of this study is to verify neonatal handling-induced sex specific differences on learning and reversal learning as well as oxidative stress parameters in the prefrontal cortex and striatum of adult rats. Litters of rats were non-handled or handled (10 min/day, days 1-10 after birth). In adulthood, learning and reversal learning were evaluated using a Y maze associated with palatable food in male and female rats. Morris water maze reversal learning was verified in males. Oxidative stress parameters were evaluated in both genders. Male neonatal handled animals had a worse performance in the Y maze reversal learning compared to non-handled ones and no difference was observed in the water maze reversal learning task. Regarding females, neonatal handled rats had a better performance during the Y maze learning phase compared to non-handled ones. In addition, neonatal handled female animals showed a decreased SOD/CAT ratio in the PFC compared to non-handled females. We conclude that neonatal handling effects on learning and memory in adult rats are sex and task specific. The sex specific differences are also observed in the evaluation of antioxidant enzymes activities with neonatal handling affecting only females.     

Vaccinia viruses isolated from cutaneous disease in horses are highly virulent for rabbits

Two genotypically distinct Vaccinia viruses (VACV), named P1V and P2V, were isolated from an outbreak of cutaneous disease in horses in Southern Brazil. We herein investigated the susceptibility of rabbits, a proposed animal model, to P1V and P2V infection. Groups of weanling rabbits were inoculated intranasally (IN) with P1V or P2V at low (10^2.5 TCID₅₀), medium (10^4.5TCID₅₀), or high titer (10^6.5TCID₅₀). Rabbits inoculated with medium and high titers shed virus in nasal secretions and developed serous to hemorrhagic nasal discharge and severe respiratory distress, followed by progressive apathy and high lethality. Clinical signs appeared around days 3-6 post-inoculation (pi) and lasted up to the day of death or euthanasia (around days 5-10). Virus shedding and clinical signs were less frequent in rabbits inoculated with low virus titers. Viremia was detected in all groups, with different frequencies. Viral DNA was detected in the feces of a few animals inoculated with P1V and P2V, low titer, and with P2V at high titer. Gross necropsy findings and histological examination showed diffuse interstitial fibrousing pneumonia with necrosuppurative bronchopneumonia and intestinal liquid content. Neutralizing antibodies were detected in all inoculated animals surviving beyond day 9pi. These results show that rabbits are highly susceptible to VACV isolated from horses, and develop severe respiratory and systemic disease upon IN inoculation. Thus, rabbits may be used to study selected aspects of VACV infection and disease.     

Deciphering the Complex Communication Networks That Orchestrate Pancreatic Islet Function

Pancreatic islets are clusters of hormone-secreting endocrine cells that rely on intricate cell-cell communication mechanisms for proper function. The importance of multicellular cooperation in islet cell physiology was first noted nearly 30 years ago in seminal studies showing that hormone secretion from endocrine cell types is diminished when these cells are dispersed. These studies showed that reestablishing cellular contacts in so-called pseudoislets caused endocrine cells to regain hormone secretory function. This not only demonstrated that cooperation between islet cells is highly synergistic but also gave birth to the field of pancreatic islet organoids. Here we review recent advances related to the mechanisms of islet cell cross talk. We first describe new developments that revise current notions about purinergic and GABA signaling in islets. Then we comment on novel multicellular imaging studies that are revealing emergent properties of islet communication networks. We finish by highlighting and discussing recent synthetic approaches that use islet organoids of varied cellular composition to interrogate intraislet signaling mechanisms. This reverse engineering of islets not only will shed light on the mechanisms of intraislet signaling and define communication networks but also may guide efforts aimed at restoring islet function and β-cell mass in diabetes.