Functional classification and central nervous projections of olfactory receptor neurons housed in antennal trichoid sensilla of female yellow fever mosquitoes, Aedes aegypti

Mosquitoes are highly dependent on their olfactory system for, e.g. host location and identification of nectar-feeding and oviposition sites. Odours are detected by olfactory receptor neurons (ORNs) housed in hair-shaped structures, sensilla, on the antennae and maxillary palps. In order to unravel the function of the olfactory system in the yellow fever vector, Aedes aegypti, we performed single-sensillum recordings from trichoid sensilla on female antennae. These sensilla are divided into four distinct morphological types. Based on the response to a set of 16 odour compounds, we identified 18 different ORN types, housed in 10 sensillum types. The ORNs responded to behaviourally relevant olfactory cues, such as oviposition attractants and sweat-borne compounds, including 4-methylcyclohexanol and indole, respectively. Two ORNs housed in these sensilla, as well as two ORNs housed in an additional sensillum type, did not respond to any of the compounds tested. The ORNs housed in individual sensilla exhibited stereotypical pairing and displayed differences in signalling mode (excitatory and inhibitory) as well as in temporal response patterns. In addition to physiological characterization, we performed anterograde neurobiotin stainings of functionally identified ORNs in order to define the functional map among olfactory glomeruli in the primary olfactory centre, the antennal lobe. The targeted glomeruli were compared with an established 3D map. Our data showed that the ORN types sent their axons to defined antennal lobe glomeruli in a stereotypic pattern.     

Clinical and epidemiologic characteristics of nodding syndrome in Mundri County,southern Sudan

Background

Nodding syndrome (repetitive nodding and progressive generalized seizures) is assuming epidemic proportions in South Sudan, Tanzania and Uganda.

Objective

To describe clinical and epidemiological features of nodding syndrome in southern Sudan based on preliminary investigations conducted in 2001 and 2002.

Method

Household surveys, clinical, electrophysiological (EEG) assessments, informant interviews and case-control studies were conducted in the town of Lui and the village of Amadi in southern Sudan.

Results

Nodding syndrome is characterized by involuntary repetitive nodding of the head, progressing to generalized seizures; mental and physical deterioration. The EEGs were consistent with progressive epileptic encephalopathy. Prevalence of Nodding syndrome in Lui and Amadi was 2.3% and 6.7% respectively. All case control studies showed a positive association between cases and Onchocerca volvulus. A history of measles was negatively associated with being a case: 2/13 of cases and 11/19 of controls had had measles: odds ratio 0.13 (95% CI 0.02, 0.76). Environmental assessment did not reveal any naturally occurring or manmade neurotoxic factors to explain Nodding Syndrome, although fungal contamination of food could not be ruled out.

Conclusion

Nodding Syndrome was strongly associated with Onchocerca volvulus. There was no evidence to suggest an environmental pollutant, chemical agent, or other toxic factor     

乙肝肝硬化并发糖尿病的健康宣教

目的探讨系统的健康宣教对乙肝肝硬化并发糖尿病患者的治疗效果及疾病控制的影响。方法通过对50例乙肝肝硬化并发糖尿病的住院患者进行回顾性总结。结果患者的心理负担减轻,对疾病的相关理论知识有所了解,对在饮食、皮肤护理以及自我监测能力等方面都有所了解和提高。结论系统的健康宣教可以对乙肝肝硬化并发糖尿病患者的治疗和疾病的控制产生非常重要的作效果。     

Birth weight for gestational age centiles for Italian neonates

Objective: To provide centiles for birth weight (BW) according to gestational age (GA) and sex for infants born in Italy.

Methods: We used records of the whole neonatal population of Tuscany, a region in Italy, from July 1991 to June 2002 as resulting from the database of the cystic fibrosis neonatal screening program (n?=?290?129). We excluded as unlikely for GA those BW that were more than two interquartile ranges above the 75th centile or below the 25th centile for each GA and gender group.

Results: We present the 3rd, 10th, 25th, 50th, 75th, 90th and 97th centiles of BW for GA from the 24th to 43rd week of gestation for male and female Italian neonates, as both tables and smoothed curves.

Conclusions: The large size of the examined population allows us to provide up-to-date, reliable BW for GA centiles for Italian newborns, especially for lower GAs.     

A feasibility study of using biodegradable magnesium alloy in glaucoma drainage device

Technological advances in glaucoma have challenged the traditional treatment paradigm. Historically incisional surgery has been used in cases of advanced disease and/or uncontrolled intraocular pressures resistant to medical or laser interventions. More recently, perhaps due to advancements in imaging, surgery has been suggested to be beneficial earlier in the treatment paradigm. Despite these trends, surgical manipulation of the tissues and unpredictability of wound healing continue to result in surgical failure. Magnesium is an essential element for human body and plays a critically important role in maintaining the functional and structural integrity of several tissues, including the eye. Due to several of its advantageous properties such as non-toxicity, biodegradability, and high biological compatibility, magnesium alloy has attracted great attention as a novel biomaterial. Biodegradable cardiovascular stents made of magnesium alloy have already been introduced into clinical practice. The purpose of this review is to determine if bioabsorbable magnesium alloys can be utilized as a promising candidate for the development of a new generation of glaucoma surgical assistive devices.     

The location of Taenia pisiformis,Taenia ovis and Taenia hydatigena in the gut of the dog and its effect on net environmental contamination with ova

Summary Autopsy of dogs 56 days after infection with either T. pisiformis, T. ovis or T. hydatigena showed that these worms could be found attached at any point along the length of the small intestine, but were most commonly in the anterior half. The mean relaxed lengths of T. pisiformis, T. ovis and T. hydatigena were 107 cm, 156 cm and 177 cm respectively. Attached gravid proglottides contained a mean of 41000 eggs each in T. pisiformis, 31000 eggs in T. hydatigena and 95000 eggs in T. ovis, whereas proglottides free in the gut contained means of only 1370, 500 and 1400 eggs respectively; therefore, the majority of eggs were released into the gut before segments passed out into the faeces. It was shown that eggs of all 3 species of worms hatched and activated in the small intestine of the dog, especially in the anterior half. Eggs of T. pisiformis which had been passaged through the intestine of the dog and stored in the faeces for 5 days were poorly infective for rabbits compared with eggs only stored in faeces. It was concluded, therefore, that during taeniid infections of dogs the point of apolysis in the gut plays a significant role in determining environmental contamination with eggs. Puppies which had been fed 10000 T. ovis eggs daily for 6 weeks prior to infection with T. ovis cysticerci showed no difference in susceptibility to the infection when compared with untreated puppies.