Vestibular destruction by slow infusion of gentamicin into semicircular canals

Intratympanic or round window application of gentamicin is often used to alleviate disabling vertigo arising from unilateral Meniere's disease; however, treatment is often accompanied by hearing loss because the drug initially enters the cochlea before diffusing to the vestibular system. In order to enhance vestibular damage and reduce the risk of hearing loss, gentamicin was infused directly into the vestibular system. An osmotic pump containing 50, 100, 200 or 400 microg/ml of gentamicin was infused into the superior semicircular canal of the chinchilla for 7 days. Afterwards, vestibular damage was evaluated by measuring the decline in hair cell density in the utricle, saccule and superior semicircular canals. Auditory damage was assessed with distortion product otoacoustic emissions (DPOAE) and outer hair cell (OHC) and inner hair cell (IHC) loss. Infusion with the two lowest gentamicin concentrations resulted in significant hair cell loss and reduced duration of the nystagmus response, but had little or no effect on OHC or DPOAE. Higher doses of gentamicin damaged cochlear hair cells and reduced the DPOAE. In conclusion, slow infusion of a low dose of gentamicin into the semicircular canals mainly damages the vestibular hair cells and inactivates the nystagmus response without damaging cochlear hair cells or DPOAE.     

Postal survey on asthma, chronic bronchitis and respiratory symptoms among adult Estonians and non-Estonians (FinEsS-study)

BACKGROUND: According to the data of the population census held in Estonia in 1989, the resident population consisted of 61.5% Estonians and 38.5% non-Estonians, the majority of them being Russians--30.3%. The aim of this study was to investigate the prevalence of asthma, chronic bronchitis and respiratory symptoms among the adults in these ethnic groups. METHODS: The study was a postal survey, similar in design to parallel studies currently in progress in Finland, Estonia and Sweden (FinEsS). RESULTS: The prevalence of physician-diagnosed asthma was 2.0%, being similar in men and women and in both Estonians and non-Estonians. The prevalence of physician-diagnosed chronic bronchitis was 10.5%. Compared with the non-Estonian population, the prevalence was much lower among Estonians (7.9% vs. 13.5%, p<0.001). Such a difference in prevalence was observed in all age groups. The high prevalence of chronic bronchitis in non-Estonians could be related to more extensive smoking habits, smoking indoors and probably ETS exposure. The defined OR between non-Estonians vs. Estonians after correcting for the influence of smoking habits, area of domicile, age, gender, and socioeconomic group was 1.30. A similar pattern of differences between Estonians and non-Estonians was observed in respiratory symptoms. CONCLUSION: This study revealed that the prevalence of physician-diagnosed asthma in Estonians and non-Estonians was the same. Physician-diagnosed chronic bronchitis was more frequent in non-Estonians than in Estonians. A significant difference was determined in the prevalence of respiratory symptoms, especially among those common to chronic bronchitis. The differences remained significant after correction for possible confounders.     

Diallyl trisulfide modulates cell viability and the antioxidation and detoxification systems of rat primary hepatocytes

This study investigated the effects of various concentrations of diallyl trisulfide (DATS) and incubation times on cell viability, glutathione (GSH) content, and GSH-related enzyme activity in rat primary hepatocytes. Isolated and cultured primary rat hepatocytes were used as an experimental model. Cells were treated with 0 (control), 0.025, 0.05, or 0.25 mmol/L DATS for 0, 4, 8, or 24 h. After 24 h of treatment, some cells were incubated in fresh medium without DATS for an additional 24 h (48-h incubations). Based on lactate dehydrogenase (LDH) leakage and morphological examination, hepatocytes treated with 0.025 mmol/L DATS did not differ from the control cells at 4, 8, 24, and 48 h of incubation. However, LDH leakage was higher than in the control cells (P < 0.05) when the hepatocytes were treated with 0.05 or 0.25 mmol/L DATS for 4 h or more. The intracellular GSH levels of hepatocytes treated with 0.025 or 0.05 mmol/L DATS were higher than those of the control cells (P < 0.05), whereas those treated with 0.25 mmol/L DATS did not differ. The activity of glutathione reductase (GRd) was higher than in the control cells at 24 h (P < 0.05) when the hepatocytes were treated with 0.025 mmol/L DATS. When the hepatocytes were treated with 0.025 mmol/L DATS, the activity of glutathione S-transferase (GST) was higher than in the control cells at 48 h (P < 0.05). In hepatocytes treated with 0.05 mmol/L DATS, the activity of GST and glutathione peroxidase (GPx) was higher than in the control cells (P < 0.05) at 24 and 48 h of incubation. The results indicate that 0.025 or 0.05 mmol/L DATS could enhance antioxidation and detoxification capabilities by increasing the intracellular GSH level and the activity of GPx, GRd, or GST in rat primary hepatocytes. However, 0.05 or 0.25 mmol/L DATS might adversely affect the viability of hepatocytes.     

Microcapsules from starch granules

A preparation of microcapsules from granular potato starch by its prolonged (up to 48 h) soaking in water is proposed. The effects of temperature and size of granules is studied. Such treatment removes the amorphous part of the granule interior, forming empty domains inside granules. Material evacuated from the granules was identified as amylopectin together with amylose. The application of such pre-treated granules for microencapsulation of various fragrant compounds (angelicalactone, diacetyl, dibenzyl ether, 2,6-lutidine and myrcene) from their vapours and from their liquid state is described. Depending on pre-treatment of starch and the microencapsulation method applied, the amount of trapped guest molecules is up to 30 wt%     

Asthma in children: Management practices among paediatricians and family physicians

OBJECTIVE:

To ascertain the variation in asthma management practices among paediatricians and family physicians to determine how to improve care.

DESIGN:

Questionnaire study of paediatricians and family physicians that focused on the use of beta₂-agonists, inhaled corticosteroids, patient asthma education, quantitative measurements of airflow and diagnostic investigations for asthma. Case scenarios were used in the questionnaire.

RESULTS:

The response rate was 66% (415 of 632) among paediatricians and 42% (1156 of 2750) among family physicians. In general, both groups followed consensus guidelines. There were some differences in management practices among paediatricians and family physicians. Paediatricians were more likely to develop an action plan and less likely to use xanthines or inhaled anticholinergic agents. However, family physicians were more likely to use spirometry or home peak expiratory flow rates to make a diagnosis of asthma.

CONCLUSION:

Family physicians and paediatricians require a different focus on educational interventions to improve the care of children with asthma.     

Prostaglandin E2 is involved in the increase of cytochrome P-450 2B1 expression by alpha-tocopheryl succinate in primary rat hepatocytes in the presence of phenobarbital

The modulation of cytochrome P-450 2B1 expression by alpha-tocopheryl succinate and whether prostaglandin E2 is involved in this modulation in primary rat hepatocytes in the presence of phenobarbital were investigated. A primary rat hepatocyte culture model that faithfully reproduces the phenobarbital response observed in vivo was used. Intracellular alpha-tocopherol content was dose dependently increased by alpha-tocopheryl succinate incubation. Hepatocytes were demonstrated to have prostaglandin E2-synthesizing capability. alpha-Tocopheryl succinate inhibited prostaglandin E2 synthesis by hepatocytes and increased cytochrome P-450 2B1 expression in the presence of phenobarbital; however, it had little effect on intracellular cAMP level. To mimic the exogenous source of prostaglandin E2 from nonparenchymal cells, various concentrations of prostaglandin E2 were added to the cell culture. High doses of exogenous prostaglandin E2 (100 and 1,000 nM) inhibited the cytochrome P-450 2B1 expression in the presence of phenobarbital compared with low doses (1 and 10 nM); however, the presence of high doses of prostaglandin E2 had no effect on intracellular cAMP level. Forskolin significantly increased intracellular cAMP level and inhibited cytochrome P-450 2B1 expression in the presence of phenobarbital. The results of this study indicate that alpha-tocopheryl succinate increases cytochrome P-450 2B1 expression via its inhibition of prostaglandin E2 synthesis in the presence of phenobarbital; however, changes in intracellular cAMP level are not related to cytochrome P-450 2B1 expression.     

Chemical composition and toxicity of Taiwanese betel quid extract.

In this genotoxic study, the Ames Salmonella microsome test showed that an aqueous extract of betel quid did not induce mutagenicity in Salmonella typhimurium strains TA98 and TA100. Mammalian cell studies (Chinese hamster ovary K1 cell; CHO-K1 cell) revealed that only higher concentrations (100 and 1000 microg/ml) of aqueous extract weekly increased the frequencies of sister-chromatid exchange (SCE) in the absence of S9. Animal (male Sprague-Dawley rat) studies showed that low-dose feeding (0.53 g dry aqueous extract/kg diet) significantly increased the activities of glutathione (GSH) peroxidase and cytoplasmic glutathione S-transferase (cGST) of liver, high-dose feeding (26.5 g dry aqueous extract/kg diet) lowered the contents of GSH and total glutathione. The effect of an aqueous extract of betel quid on the oxidation of 2'-deoxyguanosine (2'-dG) to 8-hydroxy-2'-deoxyguanosine (8-OH-dG) evaluated that this aqueous extract may act as a pro-oxidant at lower dosage and may be dependent on the iron ions in the model system. However, the aqueous extract of betel quid showed antioxidant activity at higher doses by the ability of the scavenging effect of the hydroxyl radicals.     

马鞭草环烯醚萜苷类成分的研究

目的：探索马鞭草抗早孕有效成分。方法：甲醇渗漉提取，反复硅胶柱层析分离，理化常数和光谱分析鉴定化合物结构。结果：从马鞭草甲醇提取物中分离并鉴定了３个环烯醚萜苷，分别为马鞭草苷（Ⅰ）、３，４二氢马鞭草苷（Ⅱ）和５－羟基马鞭草甘（Ⅲ）。结论：其中Ⅱ为新的天然化合物。     

Children's over‐the‐counter medicines pharmacoepidemiological (COPE) study

Objective To quantify the extent and types of minor ailments in children that were presented at community pharmacies and the types of over‐the‐counter (OTC) medicines purchased in response to these ailments. Method Data on all requests and sales of OTC medicines for children (aged 16 years and under) and consultations for minor ailments in children were recorded in eight community pharmacies for one week every month over a 12‐month period. Participants were members of the public who consulted the pharmacists or other pharmacy staff in the community pharmacies. Key findings A total of 976 consultations was recorded with 61.5% requesting an OTC medicine by name and 38.5% by symptom presentation. An average of 10.2 consultations was made per pharmacy per week. Requests for treatment were usually made within five days of symptom occurrence (86%). Most of the consultations were made by mothers (75%), although 17% were by fathers. The most commonly purchased OTC medicine was paracetamol. There were five requests for aspirin and one was for a 2‐year old child. A total of 62 cases (6%) was referred back to the child's primary care physician (general practitioner). Conclusions Symptoms related to cough and cold were the most common problems in children presenting to community pharmacies for treatment. Paracetamol was the most widely used OTC medicine in children. Pharmacy staff do question the request for OTC medicines such as aspirin, to ensure its safe use. Community pharmacies play an important role as the first port of call for advice on minor ailments in children and have an opportunity to provide health promotion to carers of children.