Hyperoxia enhances slow-wave forebrain states in urethane-anesthetized and naturally sleeping rats.

Oxygen (O2) is a crucial element for physiological functioning in mammals. In particular, brain function is critically dependent on a minimum amount of circulating blood levels of O2 and both immediate and lasting neural dysfunction can result following anoxic or hypoxic episodes. Although the effects of deficiencies in O2 levels on the brain have been reasonably well studied, less is known about the influence of elevated levels of O2 (hyperoxia) in inspired gas under atmospheric pressure. This is of importance due to its typical use in surgical anesthesia, in the treatment of stroke and traumatic brain injury, and even in its recreational or alternative therapeutic use. Using local field potential (EEG) recordings in spontaneously breathing urethane-anesthetized and naturally sleeping rats, we characterized the influence of different levels of O2 in inspired gases on brain states. While rats were under urethane anesthesia, administration of 100% O2 elicited a significant and reversible increase in time spent in the deactivated (i.e., slow-wave) state, with concomitant decreases in both heartbeat and respiration rates. Increasing the concentration of carbon dioxide (to 5%) in inspired gas produced the opposite result on EEG states, mainly a decrease in the time spent in the deactivated state. Consistent with this, decreasing concentrations of O2 (to 15%) in inspired gases decreased time spent in the deactivated state. Further confirmation of the hyperoxic effect was found in naturally sleeping animals where it similarly increased time spent in slow-wave (nonrapid eye movement) states. Thus alterations of O2 in inspired air appear to directly affect forebrain EEG states, which has implications for brain function, as well as for the regulation of brain states and levels of forebrain arousal during sleep in both normal and pathological conditions. NEW & NOTEWORTHY We show that alterations of oxygen concentration in inspired air biases forebrain EEG state. Hyperoxia increases the prevalence of slow-wave states. Hypoxia and hypercapnia appear to do the opposite. This suggests that oxidative metabolism is an important stimulant for brain state.

Rehabilitation of amelogenesis imperfecta using a reorganized approach: a case report.

Amelogenesis imperfecta is a genetic disorder that causes defective enamel development in both the primary and permanent dentitions. Significant tooth structure damage often results in various pulpal symptoms, occlusal disharmony, impaired function, and esthetic disfigurement. These problems pose great challenges to the clinician when rehabilitating patients with amelogenesis imperfecta. This case report describes an uncomplicated and logical way to reorganize, temporize, and completely restore an extensively damaged dentition caused by amelogenesis imperfecta.

Effect of burn-out temperature on magnetic keepers in cast noble metal alloy posts.

STATEMENT OF PROBLEM: Early loss of magnetic keepers in cast gold posts is seen in clinical practice. PURPOSE: The purpose of this vitro study was to investigate the effect of burn-out temperature on the retention of magnetic keepers in cast gold alloy and on the thickness of the oxide layer at the keeper-alloy interface. MATERIAL AND METHODS: One hundred and five keepers (Magfit EX) were cast with gold alloy (Protor 3) at 3 different burn-out temperatures: 500 degrees C, 600 degrees C, or 700 degrees C (n=35). To test for retention of keepers, 60 specimens (n=20) were tested to failure in tension mode in a universal testing machine (UTM); 45 specimens (n=15) were sectioned, and the interface was evaluated under a scanning electron microscope (SEM). Tensile force data were analyzed with 1-way ANOVA, and SEM data were analyzed with 1-way repeated measures ANOVA. Bonferroni multiple comparisons were performed for post hoc analysis (alpha=.05). RESULTS: Retention of the keepers was significantly higher at lower burn-out temperatures (P<.001). The retention of the keepers became unpredictable and immediate failures were observed at a burn-out temperature of 700 degrees C. Oxide formation at the keeper-alloy interface was significantly less at lower burn-out temperatures (P<.001). CONCLUSIONS: A burn-out temperature of 500 degrees C for casting the Magfit EX keeper with type IV high-strength gold alloy is recommended.

Bullous lesions in Henoch-Schönlein purpura.

Henoch-Schönlein purpura (HSP) is a small-vessel vasculitis characterized by purpura, arthritis, abdominal pain, and hematuria. It is the most common form of vasculitis affecting children. The skin manifestations typically present as palpable purpura over the buttock and the lower extremities, but bullous lesions are particularly rare in children. We report a case of HSP presented as painful bullae on both lower limbs.

A retrospective clinical evaluation of two-unit cantilevered resin-bonded fixed partial dentures.

BACKGROUND: The authors conducted a study to examine the clinical performance of two-unit cantilevered resin-bonded fixed partial dentures (RBFPDs) that were inserted at The Prince Philip Dental Hospital, University of Hong Kong. METHODS: The authors recalled patients who had received two-unit cantilevered RBFPDs at least 24 months before the recall examination. The authors recorded the following data: patient's sex and age, operator's experience, prosthesis cementation date, endodontic treatment if performed, bone support, tooth mobility, the presence of shim-stock contacts on the abutment or pontic in intercuspal position, and the presence of aproximal axial contacts adjacent to the prosthesis. They also recorded the date of any debonding with subsequent treatment. They asked the patients qualitative questions about their prostheses. RESULTS: A total of 269 prostheses were placed in 214 patients and had a mean service life of 51.7 months +/- 19.5 months standard deviation, with a range of 13.2 to 141.6 months. Of 14 failed prostheses, 12 debonded, resulting in a success rate of 94.8 percent and clinical retention rate of 95.5 percent. No discernable rotation or drifting of the abutments was apparent in any of the prostheses. Overall patient satisfaction with RBFPDs was good, with an average assessment score of 8.5. CONCLUSIONS: The authors observed a 95.5 percent clinical retention rate of 269 two-unit RBFPDs, with no apparent drifting of the abutments. Longer-term follow-up studies are required. CLINICAL IMPLICATIONS: Two-unit RBFPDs are conservative and clinically retentive prostheses in the short to medium term.

Use of chopsticks in Chinese children.

OBJECTIVE: There has been no study on the developmental stage of acquiring the skill of using chopsticks, which is a common eating tool of the Orientals. We aimed to obtain a developmental profile for achieving the skills of chopsticks manipulation in Chinese children and to assess the correlation between chopsticks manipulation and the level of achieving independence in 'eating' item in the Functional Independence Measure of children (WeeFIM). We also studied the relationship between demographic and environmental factors and the age of achieving chopstick manipulation. METHODS: Direct interview with the mothers of 445 non-disabled children who were randomly selected from the community. A chopsticks score (CS) of 1 was defined as children who could use chopsticks to finish more than half the meal, and a CS of 0 as failure to do so. RESULTS: The mean age of achieving a CS of 1 was 4.6 years. At 6.7 years, all these children achieved this skill. There was a significant relationship between age of achieving the skills of chopsticks and the level of attaining independence in 'WeeFIM eating' score. (P < 0.001) However, there was no correlation of age of achieving CS of 1 with sex, social class or the presence of a domestic helper. CONCLUSION: Most non-disabled Chinese children can achieve the visual motor skill of using chopsticks at 4.6 years. There was also a correlation with the age of achieving independence in the WeeFIM eating score. The skill of using chopsticks should be added as part of the tools, apart from spoons or forks, for scoring WeeFIM in Chinese children.

Functional Independence Measure (WeeFIM) for Chinese children: Hong Kong Cohort.

BACKGROUND: The Functional Independence Measure (WeeFIM) for children is a simple-to-administer scale for assessing independence across 3 domains in American children. WeeFIM was based on a conceptual framework by the World Health Organization (1980) of pathology, impairment, disability and handicap, and the "burden of care." WeeFIM is useful in assessing functional independence in children aged 6 months to 7 years. It can be used for children with developmental disabilities aged 6 months to 21 years. Normative WeeFIM data had been validated for American children. Because of cultural and environmental differences among countries, normative data for the Chinese population are needed. With a normative database, the progression of independence at home and in the community can be evaluated. WeeFIM is an 18-item, 7-level ordinal scale instrument that measures a child's consistent performance in essential daily functional skills. Three main domains (self-care, mobility, and cognition) are assessed by interviewing or by observing a child's performance of a task to criterion standards. WeeFIM is categorized into 2 main functional streams: "Dependent" (ie, requires helper: scores 1-5) and "Independent" (ie, requires no helper: scores 6-7). Scores 1 (total assistance) and 2 (maximal assistance) belonged to the "Complete Dependence" category. Scores 3 (moderate assistance), 4 (minimal contact assistance), and 5 (supervision or set-up) belonged to the "Modified Dependence" category. Scores 6 (modified independence) and 7 (complete independence) belonged to the "Independent" category. The WeeFIM is a 7-level criterion-specific ordinal scale. Level 7 requires no assistance for the child and the child completes the task independently without requiring a device. During the task, there is no concern about safety or taking an inordinate amount of time. Level 6 reflects modified independence and includes use of an assistive device or not completing the task in a timely or safe manner. OBJECTIVE: To examine the utility of the WeeFIM in Chinese children and to create a normative WeeFIM profile suitable for Chinese children. METHOD: Direct interviews were conducted for 445 normal Chinese children, aged 6 months to 7 years, in the community. RESULTS: 1. WeeFIM total score and 3 domains subscores versus age. The total WeeFIM scores increased progressively with age, reaching a plateau at 72 months. There was a progressive increase in subscores of self-care, mobility, and cognition independence between 6 to 62 months, especially between 6 to 45 months. Similarly, the WeeFIM self-care subscores increased progressively with age, reaching a plateau at around 72 months. The WeeFIM mobility subscores increased progressively with age, reaching a plateau at around 54 months. The WeeFIM cognition subscores increased progressively with age, reaching a later plateau at around 80 months. 2. WeeFIM subtotal scores versus age. The total WeeFIM score and 3 domain subscores correlated significantly with age. We further classified the 18 items into 3 groups according to the degree of correlation with age. Most items had high correlation with Spearman's correlation coefficient of rho >0.8. Only 1 item (chair transfer) showed moderate correlation with rho = 0.7-0.8. The item "walk" had the lowest correlation with rho = 0.6-0.7. 3. Chronological order for achieving different items. The 50th percentile of age in months for achieving level 6 (modified independence) of the 18 items were compared and ranked according to the age of achieving level 6. In creating a developmental scale of achievement of level 6 (modified independence) for all 18 items, the developmental sequence clustered in the following order: chair transfer (order 1) and walk (order 2) were achieved much earlier (at 18 and 24 months, respectively). Thereafter, there was a clustering of 4 items achieved at around 45 months: toilet transfer (order 3), stair (order 4), expression (order 5), and social interaction (order 6). Then, 9 items were achieved at around 54 to 56 months: tub or shower transfer (order 7), eating (order 8), bathing (order 9), bowel management (order 10), dressing of lower body (order 11), comprehension (order 12), dressing of upper body (order 13), bladder management (order 14), and grooming (order 15). At 60 months, the following ranked in order: memory (order 16), problem-solving (order 17), and toileting (order 18). 4. Impact of sex factor. Girls aged 22 to 45 months had higher scores in self-care subscores and cognition subscores. From 63 months onwards, boys had statistically significant higher scores in mobility subscores. Otherwise, there was no statistically significant difference in WeeFIM scores for different age groups. 5. Impact of domestic helpers. There was also significant difference for self-care subscore with the presence of a maid at home. Those children with a maid at home obtained lower self-care subscores. However, the mobility and cognition subscores were not affected. CONCLUSION: We have created a normative functional independence profile for Chinese children by adapting the American-based WeeFIM. There were cultural differences when compared with American children. Interestingly, Chinese children in Hong Kong scored better than their American counterparts in domain 1 (self-care) in all ages. This might be attributable to early attendance in preschool settings where children are taught to tend to their needs. Even for domain 2 (mobility), the higher scores in younger Chinese children in Hong King (<3 years) might be explained by earlier attendance in preschool settings. The American children did catch up after 3 years. As for domain 3 (cognition), the local educational system emphasized reading, writing, memorizing materials, and social interaction. Thus, Chinese children in Hong Kong had better cognition scores until 42 months, when their American counterparts caught up by attending preschool. There are definitely environmental and cultural practices affecting functional independence in both ethnic groups, especially in the upper age range (>4 years) both in America and Hong Kong. Thus, a locally validated WeeFIM instrument should be adopted for Chinese children. Our study demonstrated that WeeFIM could be used as a functional independence measure for Chinese children. Hong Kong has a different cultural background compared with America; thus, usage of WeeFIM with different age criteria for achieving independence should be adopted.