Seasonal variability of the essential oil of Hesperozygis ringens (Benth.) Epling

This study was developed to evaluate the effect of seasonality on the yield and chemical composition of the essential oil (EO) of Hesperozygis ringens (Benth.) Epling, a native species from the Brazilian Pampa. Leaves were collected from four specimens of a single population in each of the four seasons for a year and were extracted in triplicate by hydro-distillation for 2 hours. The yield of EO (% w/w) was calculated on fresh weight basis (FWB), and the 16 oil samples were analyzed by gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) were used as statistical tools to evaluate differences in chemical composition. The highest yields were obtained in autumn, spring and summer (2.32-4.38%), while the lowest yields were detected in winter, ranging from 1.15 to 1.91%. Oxygenated monoterpenoids were the predominant class of chemical constituents in the EO obtained in all seasons, showing the highest contents in autumn and summer, and pulegone was identified as a major compound, whose contents varied between 54.13 and 81.17%. The EO samples were divided into three chemical groups by HCA and PCA and were assigned to the same group, except for the three samples gathered in winter. The results showed a seasonal influence on the yield and chemical composition of the EO.

Effect of (+)-dehydrofukinone on GABAA receptors and stress response in fish model

(+)-Dehydrofukinone (DHF) is a major component of the essential oil of Nectandra grandiflora (Lauraceae), and exerts a depressant effect on the central nervous system of fish. However, the neuronal mechanism underlying DHF action remains unknown. This study aimed to investigate the action of DHF on GABA_A receptors using a silver catfish (Rhamdia quelen) model. Additionally, we investigated the effect of DHF exposure on stress-induced cortisol modulation. Chemical identification was performed using gas chromatography-mass spectrometry and purity was evaluated using gas chromatography with a flame ionization detector. To an aquarium, we applied between 2.5 and 50 mg/L DHF diluted in ethanol, in combination with 42.7 mg/L diazepam. DHF within the range of 10-20 mg/L acted collaboratively in combination with diazepam, but the sedative action of DHF was reversed by 3 mg/L flumazenil. Additionally, fish exposed for 24 h to 2.5-20 mg/L DHF showed no side effects and there was sustained sedation during the first 12 h of drug exposure with 10-20 mg/L DHF. DHF pretreatment did not increase plasma cortisol levels in fish subjected to a stress protocol. Moreover, the stress-induced cortisol peak was absent following pretreatment with 20 mg/L DHF. DHF proved to be a relatively safe sedative or anesthetic, which interacts with GABAergic and cortisol pathways in fish.

Conceptualizing and measuring potentially inappropriate drug therapy

WHAT IS KNOWN AND OBJECTIVE

Elderly people are the principal consumers of prescription drugs. The more the medication used by the patient, the greater the likelihood there is of the patient being subjected to potentially inappropriate drug therapy (PIDT). PIDT has been measured in the literature with both implicit and explicit tools. The purpose of this review was to assess the use of tools to detect PIDT in various studies and to determine which terms are used to refer to PIDT in practice.

METHODS

A systematic review was conducted according to the following steps: the first was identification. In this step, studies were selected from different combinations of the descriptors 'aged', 'elderly', 'inappropriate prescribing' and 'drug utilization' in three different languages, using the Embase, Medline, Scielo, Scopus and Web of Science databases. Second, the papers that satisfied the inclusion criteria for data extraction were carefully examined by three evaluators to determine the tools used and terms that referred to PIDT.

RESULTS AND DISCUSSION

From the combinations of keywords, 8610 articles were found. At the end of the selection process, 119 of the articles complied with the specified criteria. The degree of agreement among evaluators was moderate for the study titles (κ1  = 0·479) and substantial for abstracts (κ2  = 0·647). With respect to the PIDT evaluation criteria used by the studies, 27·7% used two criteria. Of the 27 evaluation criteria identified, the Beers criteria were used by 82·3% of the studies. More than 50 different terms to identify PIDT were found in the literature.

WHAT IS NEW AND CONCLUSION

This review is the first study to conceptualize and discuss terms that refer to PIDT. At present, there is no consensus regarding terms used to refer to PIDT, with over 50 different terms currently in use. This review shows an increase in the number of articles aimed at evaluating PIDT using implicit and explicit tools.

Larvicidal activity of Brazilian plant essential oils against Coenagrionidae larvae

Odonate larvae can be serious pests that attack fish larvae, postlarvae, and fingerlings in fish culture tanks, causing significant loss in the supply and production of juveniles. This study reports a screen of the essential oils (EOs) of Nectandra megapotamica (Sprengel) Mez, Nectandra grandiflora Nees, Hesperozygis ringens (Bentham) Epling, Ocimum gratissimum L., Aloysia gratissima (Gillies & Hooker) Troncoso, and Lippia sidoides Chamisso against Coenagrionidae larvae. In addition, the most effective EO and its 50% lethal concentration (LC50) and chemical analysis are described. The larvae of Acanthagrion Selys, Homeoura Kennedy, Ischnura Charpentier, and Oxyagrion Selys were used to assess the EO effects. EO obtained from H. ringens, O. gratissimum, and L. sidoides showed the highest larvicidal effects at 19 h of treatment. The major constituents of the EO of H. ringens include pulegone and limonene, while eugenol and Z-beta-ocimene predominate in the EO of O. gratissimum, and carvacrol and rho-cymene were the major compounds of the EO of L. sidoides. Leaf EOs from H. ringens, O. gratissimum, and L. sidoides showed activity against Coenagrionidae larvae at similar concentrations with LC50s of 62.92, 75.05, and 51.65 microl liter(-1), respectively, and these were considered the most promising treatments.

Trypanosoma cruzi-cardiomyocytes: new contributions regarding a better understanding of this interaction

The present paper summarizes new approaches regarding the progress done to the understanding of the interaction of Trypanosoma cruzi-cardiomyocytes. Mannose receptors localized at the surface of heart muscle cell are involved in binding and uptake of the parasite. One of the most striking events in the parasite-heart muscle cells interaction is the disruption of the actin cytoskeleton. We have investigated the regulation of the actin mRNA during the cytopathology induced in myocardial cells by the parasite. T. cruzi invasion increases calcium resting levels in cardiomyocytes. We have previously shown that Ca2+ ATPase of the sarcoplasmic reticulum (SERCA) is involved in the invasion of T. cruzi in cardiomyocytes. Treating the cells with thapsigargin, a drug that binds to all SERCA ATPases and causes depletion of intracellular calcium stores, we found a 75% inhibition in the T. cruzi-cardiomyocytes invasion.

An epidemic of renal failure among Australian Aboriginals

OBJECTIVE

To define recent trends (1993-1996) in incidence of endstage renal disease (ESRD) among Australian Aboriginal people in the Top End of the Northern Territory (NT).

DESIGN

Analysis of hospital and clinical records of the Darwin-based ESRD treatment program from 1993 to 1996 and comparison with data accumulated since 1978.

PARTICIPANTS

All people entering the ESRD treatment program from 1978 to 1996.

MAIN OUTCOME MEASURES

Number of patients treated for ESRD; their ethnicity, age and sex; comorbidities in Aboriginal patients; treatment methods and outcomes.

RESULTS

More Aboriginal people presented with ESRD between 1993 and 1996 (87) than in the previous 15 years of the program (68). The incidence of ESRD in Aboriginals reached 838 per million in 1996, and is doubling every 4 years. Aboriginal people presenting with ESRD are younger than non-Aboriginal people with ESRD, and, in contrast to non-Aboriginals, ESRD rates are higher in women than men. The numbers and proportions of Aboriginal ESRD patients who have hypertension, type 2 diabetes and cardiac disease are rising. Haemodialysis remains the most common form of treatment, and the number of dialysis treatments is doubling every 2.5 years. Only 9% of Aboriginal patients entering the program in 1993-1996 were treated with chronic ambulatory peritoneal dialysis and only 3% received transplants. Despite their younger age, survival of Aboriginal people on dialysis is low (median 3.3 years v. 6.5 years in non-Aboriginals), and graft survival after transplant is poor (37% at 5 years v. 88% in non-Aboriginals). Survival has not improved in the past 4 years, with fewer deaths from infection offset by more deaths from cardiovascular disease.

CONCLUSIONS

The predicted doubling of ESRD incidence among Aboriginal people by the year 2000 will add an enormous burden to limited resources. Risk factors for renal disease underlie all the excess morbidity and mortality in NT Aboriginal adults, and arise out of accelerated lifestyle changes and socioeconomic disadvantage. Better living conditions and education, robust and integrated primary healthcare programs, and systematic screening for early renal disease and treatment of those with established disease are all matters of urgency.

Excessive rates of childhood mortality in the Northern Territory, 1985-94

OBJECTIVES

To estimate the post-infant/childhood mortality rate (1-14 years) in the Northern Territory (NT) of Australia.

METHODS

A retrospective study of post-infant death in the 10 years 1985-94 inclusive in the NT.

RESULTS

Two hundred and forty-four deaths were identified. Compared to a non-Aboriginal, an Aboriginal child was twice as likely to die from accidents, 11 times more likely to die from infection and 3.2 times more likely to die from all causes. Road traffic accidents were the leading cause of accident mortality in Aboriginal children. All children who died in collisions or rollovers were unrestrained. Drowning was the major cause of death amongst non-Aboriginal children aged 1-4 years; none of the residential pools in which drowning occurred had fencing which complied with the recommended Australian fencing standards. Mortality rates from infection were highest in Aboriginal children aged 1-4 years. The overall mortality rate decreased over the 10-year period with a significant reduction in non-Aboriginal but not in Aboriginal children.

CONCLUSIONS

NT children aged 1-14 years have higher mortality rates than their Australian counterparts and these are significantly higher in Aboriginal compared to non-Aboriginal children. Legislation and enforcement of isolation pool fencing, car seat restraints and safer driving on rural roads could have a significant impact on reducing accident mortality.

Home oxygen management of neonatal chronic lung disease in Western Australia

OBJECTIVE

To describe the course and management of infants with neonatal chronic lung disease who were discharged home on low-flow supplemental oxygen.

METHODOLOGY

Retrospective case series in Western Australia.

RESULTS

Fifty-six neonates born in the 6 year period 1987-92 inclusive were discharged home on supplemental oxygen. The median gestational age was 27 weeks (range 22-40), median birthweight 865 g (range 450-3350), median oxygen flow rates 125 mL/min (range 30-850). The median corrected age at discharge was 1 month (range term-9.5) and this had decreased throughout the study period. Acute hospital readmissions were common (36 of 56, 64%). The majority of these admissions were for wheezing illnesses. Three infants died. The median corrected age at weaning from day oxygen was 4 months (range term-33) and from night oxygen was 6 months (range 2-38). Monitoring of oxygen saturation in air, in low-flow oxygen and in the overnight sleep study were important non-invasive guides in deciding when patients were ready for discharge, reducing the oxygen flow rate and when oxygen could be ceased, respectively.

CONCLUSIONS

The home oxygen programme enables infants with neonatal chronic lung disease to be discharged home earlier, is safe, and well accepted by parents and community health care workers.