Acoustic histology of dental tissues

New data on tooth enamel and dentin microstructure, obtained by acoustic microscopy methods, which are based on evaluation of distribution of the local elastic and mechanical properties, are presented. The results demonstrate that the acoustic microscopy methods are more sensitive to changes in mechanical properties of dental tissues in caries in comparison with optic microscopy.     

Enterovirus uveitis

Enterovirus uveitis (EU) is a new infant eye disease that was first observed in 1980. Three distinct subtypes of human echoviruses, EV19/K, EV11/A and EV11/B, caused five hospital outbreaks of EU in different Siberian cities in 1980-1989, affecting approximately 750 children, predominantly below 1 year of age. Sporadic EU cases were also retrospectively diagnosed in other regions of Russia and in different countries of the Former Soviet Union. The illness was characterised by rapid iris destruction and severe complications, including cataract and glaucoma. The disease has been a subject of intensive studies and was reproduced in lower primates after intraocular inoculation of isolated enterovirus strains. Importantly, prototype EV11 and EV19 strains did not induce notable disease in experimental monkeys. Some of the EU-causing strains were shown to be similar phylogenetically and in their pathogenetic properties to the enterovirus strains associated with multisystem hemorrhagic disease of newborns. In this review we present a summary of the vast epidemiological, virological, clinical and experimental data on this new form of ophthalmic infection.     

Early prophylactic inhaled beclomethasone in infants less than 1250 g for the prevention of chronic lung disease

OBJECTIVE:

Inflammation plays an important role in the development of chronic lung disease (CLD), which has become a major cause of morbidity in surviving infants less than 1250 g at birth. The authors hypothesized that the progression of this inflammation and, therefore, the establishment of CLD would be decreased with the use of early prophylactic inhaled corticosteroids. Short, and long term respiratory and neurodevelopmental outcomes were also examined.

DESIGN:

A double-blind, randomized placebo controlled trial.

SETTING:

Level-III neonatal intensive care unit.

POPULATION STUDIED:

Sixty infants less than 1250 g at birth, diagnosed with respiratory distress syndrome and requiring ventilatory support at 72 h of age were enrolled in the study.

INTERVENTION:

Infants enrolled received either placebo or beclomethasone diproprionate by a metered dose inhaler, which was used in-line with the ventilator circuit while the infant was ventilated and then via a spacer until 28 days of age.

RESULTS:

Thirty infants were given beclomethasone and 30 were given placebo. There were two deaths in each group. Among the surviving infants, the frequency of moderate-to-severe CLD was 17% in each study group. Mean time to extubation was not different for beclomethasone compared with placebo at 16.4 and 12.5 days (P=0.12), respectively. The requirement for intravenous corticosteroids was lower in the beclomethasone-treated group (RR 0.67, 95% CI 0.43 to 1.04), although this difference was not statistically significant. The incidence of growth failure, infection and intraventricular hemmorhage did not differ between the two groups. Long term outcomes were not different with respect to the incidence of respiratory re-admissions, cerebral palsy, developmental delay, blindness or deafness.

CONCLUSIONS:

Early treatment with inhaled beclomethasone diproprionate did not reduce the incidence of CLD or decrease the duration of mechanical ventilation. The decrease in intravenous corticosteroid use was not statistically significant. Long term outcome was not affected.     

Speed of visual processing increases with eccentricity

The visual system has a duplex design to meet conflicting environmental demands: the fovea has the resolution required to process fine spatial information, but the periphery is more sensitive to temporal properties. To investigate whether the periphery's sensitivity is partly due to the speed with which information is processed, we measured the full timecourse of visual information processing by deriving joint measures of discriminability and speed, and found that speed of information processing varies with eccentricity: processing was faster when same-size stimuli appeared at 9 degrees than 4 degrees eccentricity, and this difference was attenuated when the 9 degrees stimuli were magnified to equate cortical representation size. At the same eccentricity, larger stimuli are processed more slowly. These temporal differences are greater than expected from neurophysiological constraints.     

Effect of tumour and chemoradiotherapy on oesophageal motility

Background The contribution of dysmotility to dysphagia in oesophageal cancer is unclear. Aim To examine oesophageal motility in patients with oesophageal carcinoma and to assess the effect of chemoradiotherapy on motility. Methods Stationary manometry and 24-hour pH-metry were performed in 12 patients with oesophageal carcinoma and one week following completion of chemoradiotherapy using 5-fluorouracil (5-FU), cisplatin and 40Gy radiotherapy. Results All patients had abnormal motility prior to treatment. Peristalsis was impaired in 11 patients with a mean (SD) of 25% (9) of waves normally propagated. Eight patients had 20% or more simultaneous waves. Following chemoradiotherapy, the percentage of waves normally propagated increased from 25% (9) to 52% (10) (p < 0.03) and normal peristalsis was restored in four patients. The percentage of simultaneous waves decreased from 38% (11) to 21.6% (10) (p=0.129) while the percentage of dropped or increased waves decreased from 20% (11) to 8.3% (4) (p=0.264). Conclusions Oesophageal motility is disturbed in oesophageal cancer. Dysphagia in oesophageal cancer may be partly explained by oesophageal dysmotility. This is improved by chemotherapy.     

Pulmonary cystic hydatid disease in Ireland

Background Hydatid disease is rare in Ireland and its incidence and prevalence are unknown. Most cases are diagnosed by a combination of clinical findings, morphological features on imaging and by serological testing. Aims We describe an Irish case of pulmonary hydatid disease detected at bronchoscopy by bronchoalveolar lavage, and discuss the diagnosis and treatment of the disorder.     

The Health Trade-off of Rural Residence for Impaired Older Adults: Longer Life, More Impairment

CONTEXT: Years lived with and without physical impairment are central measures of public health. PURPOSE: We sought to determine whether these measures differed between rural and urban residents who were impaired at the time of a baseline measurement. We examined 16 subgroups defined by rural/urban residence, gender, race, and education. METHODS: This is a 20-year retrospective cohort study, following 2,939 Americans who were aged 65-69 in 1982 and physically impaired at the time of the baseline measurement, with data from the National Long-Term Care Survey. Interpolated Markov chain analysis and microsimulation estimated life expectancy at age 65 and expected number of years with physical impairment. Impairment was defined as requiring help in 1 or more activities of daily living. FINDINGS: Among older individuals with physical impairments at baseline, rural residents lived notably longer than urban residents. In all but 1 group, rural residents lived more years with physical impairment, and they also had a notably larger proportion of remaining life impaired. CONCLUSIONS: Results suggest a notable public health impact of rural residence for impaired individuals, a longer expected period of impairment. Needs for services for people with impairments may be greater in rural areas.     

消化性溃疡和慢性胃炎新中药的临床定位暨试验设计

近年来,国内有大量中药新药申请,大多集中在消化系统领域,如消化性溃疡或慢性胃炎;但是几乎所有的新药试验均设计相同、结果类似。实际上,物质基础的不同,必然会带来治疗效应上的差异。因此,新药审评机构专门召集国内部分知名专家就此问题进行讨论,希望能给业界一点建议,同时也鼓励研究者应根据研究目的的不同,选择采用不同的试验设计。     

Social determinants of birthweight, ponderal index and gestational age in Sweden in the 1920s and the 1980s

This study compared the effect of social class and marital status on birth outcomes in Sweden, using (i) data on all births at the Akademiska Hospital in Uppsala from 1920 to 1924 with socioeconomic information from records at birth; and (ii) a linkage of the Medical Births Registry for all births in Sweden in November/December 1985 to the 1985 Census. Preterm births (<37 weeks) have become less common during the 20th century. Between 1920-24 and 1985, mean and median birthweight increased, as did mean ponderal index, indicating a shift to the right of the birthweight and ponderal index distributions. In 1920-24, birthweight and ponderal index were associated with the social class of the household and with the marital status of the mother. Babies of single mothers were lighter and thinner, and had a much greater probability of being born preterm. In contrast, in 1985, maternal marital status (and cohabitation status) had a weaker effect on birthweight and ponderal index. The importance of household social class for ponderal index and preterm birth changed similarly, but its importance for birthweight remained. The mediating mechanism may have changed. Mothers from farming households now gave birth to the heaviest babies (nearly 200 g heavier than those of unskilled workers). Adjustment for a number of factors, including smoking, had a limited effect on these social class differences. In conclusion, biological processes during the foetal period are systematically linked to the social circumstances of the mother, but in a different way in the 1920s and in 1985.