牛津单髁膝关节置换：长期结果

牛津膝置换是使用最广泛的膝关节单髁置换（UKR）。牛津膝在37年前开始应用,拥有一个全匹配的活动衬垫,因而磨损率非常低。牛津膝最主要的使用指征是膝关节前内侧骨关节炎,这种病人至少占所有需要行膝关节置换术患者的50％。由于这一系统的设计特点,传统UKR的反指征,如年龄、活动量、肥胖、髌股关节损害和软骨钙质沉着症等对于牛津膝均不是反指征。与全膝关节置换（TKR）相比,牛津膝提供更快的康复、更好的功能、更大的活动度和更好的术后满意度,发生并发症更少、程度更轻,病残率和死亡率更低。一个持续超过30年的研究显示在90％的病例中,牛津膝为患者终生提供了优或良的临床结果,且不需要翻修。在最近15年,牛津膝通过微创手术入路植入,涉及6000多例使用该入路牛津膝置换的9个研究报道显示,10年生存率约95％。在许多这样的研究中,医生们在拟行膝关节置换的患者中约50％使用了牛津单髁膝置换。     

Maturation of Startle Modulation

This study of the maturation of prestimulation-induced modulation of startle in 3 to 8 year old children and adults demonstrated significant effects of age on both startle magnitude and onset latency. Startle was evoked by 104dB(SPL) 50-ms bursts of white noise, and the amplitude and onset latency of the blink reflex were measured after integration of the obicularis oculi EMG. Prestimulation with 75dB 1000 Hz tones resulted in severe inhibition of both amplitude and latency in adults when 20-ms tones preceded the startling stimuli by 120 ms or 250 ms. Following sustained prestimulation for 2000 ms, the adults showed modest nonsignificant response facilitation. Eight-year-old children showed mature inhibitory and facilitatory startle amplitude modulation, but significantly less inhibition and more facilitation of onset latency compared to adults. Preschool children showed significantly less amplitude and latency inhibition and more facilitation than 8-year-olds and adults. In response to prestimulation 120 ms before startling stimuli, the preschool children actually showed latency facilitation. Modulation of startle by prestimulation is mediated by brainstem neuronal networks. These findings suggest that brainstem mechanisms which mediate startle response modulation undergo development during early childhood and do not mature until about 8 years of age.     

Surface-Bound Proteins with Preserved Functionality

Biocompatibility of materials strongly depends on their surface properties. Therefore, surface derivatization in a controllable manner provides means for achieving interfaces essential for a broad range of chemical, biological, and medical applications. Bioactive interfaces, while manifesting the activity for which they are designed, should suppress all nonspecific interaction between the supporting substrates and the surrounding media. This article describes a procedure for chemical derivatization of glass and silicon surfaces with polyethylene glycol (PEG) layers covalently functionalized with proteins. While the proteins introduce the functionality to the surfaces, the PEGs provide resistance against nonspecific interactions. For formation of aldehyde-functionalized surfaces, we coated the substrates with acetals (i.e., protected aldehydes). To avoid deterioration of the surfaces, we did not use strong mineral acids for the deprotection of the aldehydes. Instead, we used a relatively weak Lewis acid for conversion of the acetals into aldehydes. Introduction of α,ω-bifunctional polymers into the PEG layers, bound to the aldehydes, allowed us to covalently attach green fluorescent protein and bovine carbonic anhydrase to the surfaces. Spectroscopic studies indicated that the surface-bound proteins preserve their functionalities. The surface concentrations of the proteins, however, did not manifest linear proportionality to the molar fractions of the bifunctional PEGs used for the coatings. This finding suggests that surface-loading ratios cannot be directly predicted from the compositions of the solutions of competing reagents used for chemical derivatization.     

Treating acute stress disorder following mild traumatic brain injury

OBJECTIVE: Acute stress disorder permits early identification of trauma survivors who are at risk of developing chronic posttraumatic stress disorder (PTSD). This study aimed to prevent PTSD in people who developed acute stress disorder after a mild brain injury by early provision of cognitive behavior therapy. METHOD: Twenty-four civilian trauma survivors with acute stress disorder were given five individually administered sessions of either cognitive behavior therapy or supportive counseling within 2 weeks of their trauma. RESULTS: Fewer patients receiving cognitive behavior therapy than supportive counseling met criteria for PTSD at a posttreatment evaluation (8% versus 58%, respectively). There were also fewer cases of PTSD at a 6-month follow-up evaluation among those receiving cognitive behavior therapy (17%) than among those receiving supportive counseling (58%). Patients in the cognitive behavior therapy condition displayed less reexperiencing and avoidance symptoms at the follow-up evaluation than patients receiving supportive counseling. CONCLUSIONS: These findings suggest that PTSD following mild brain injury can be effectively prevented with early provision of cognitive behavior therapy.     

Impact of comorbidity on survival after surgical resection in patients with stage I non-small cell lung cancer

OBJECTIVE: As the mean age in patients with non-small cell lung cancer increases, the proportion of patients with serious comorbidity who are considered for surgical resection also increases. Patients with non-small cell lung cancer have been shown to have a higher burden of comorbidity than do patients with tumors of other sites, such as breast, prostate, colon, and head and neck. The goal of this review was to determine the impact of comorbidity on postoperative and long-term survival after surgical resection in patients with stage I non-small cell lung cancer. METHODS: A database analysis of our hospital's tumor registry included 451 patients who underwent surgical resection for pathologic stage I non-small cell lung cancer between January 1, 1994, and December 31, 1999. Comorbidity severity was prospectively determined with the Kaplan-Feinstein Index. Survival data were collected for each patient from the date of operation, with a mean duration of follow-up of 35.7 months. Bivariate statistics and Cox proportional hazards model analyses were used. RESULTS: The mean age was 64.4 years, and 249 (55%) patients were male. The distribution of overall comorbidity severity was none, 142 (31.5%); mild, 150 (33.3%); moderate, 115 (25.5%); and severe, 44 (9.8%). The overall in-hospital mortality was 2.2% (n = 10/451). There was a nonsignificant trend toward higher hospital mortality with greater comorbidity: none, 0.7% (n = 1/142); mild, 3.3% (n = 5/150); moderate, 0.9% (n = 1/115); and severe, 6.8% (n = 3/44, P =.055). Kaplan-Meier estimated survivals at 3 years for each level of comorbidity were as follows: none, 85.6%; mild, 74.8%; moderate, 68.8%; and severe, 70.0% (P <.002). After adjustment for age, sex, T status, and tumor histologic type, the relative risks of death as a function of comorbidity were mild, 1.44 (95% confidence interval 0.89-2.34); moderate, 2.28 (95% confidence interval 1.43-3.65); and severe; 1.94 (95% confidence interval 1.023-3.70). CONCLUSIONS: Comorbidity has a significant impact on survival after surgical resection of patients with stage I non-small cell lung cancer. These data may help to explain the lower than expected survival results for patients after surgical resection for stage I non-small cell lung cancer.     

Hypnotizability in acute stress disorder

OBJECTIVE: This study investigated the relationship between acute dissociative reactions to trauma and hypnotizability. METHOD: Acutely traumatized patients (N=61) with acute stress disorder, subclinical acute stress disorder (no dissociative symptoms), and no acute stress disorder were administered the Stanford Hypnotic Clinical Scale within 4 weeks of their trauma. RESULTS: Although patients with acute stress disorder and patients with subclinical acute stress disorder displayed comparable levels of nondissociative psychopathology, acute stress disorder patients had higher levels of hypnotizability and were more likely to display reversible posthypnotic amnesia than both patients with subclinical acute stress disorder and patients with no acute stress disorder. CONCLUSIONS: The findings may be interpreted in light of a diathesis-stress process mediating trauma-related dissociation. People who develop acute stress disorder in response to traumatic experience may have a stronger ability to experience dissociative phenomena than people who develop subclinical acute stress disorder or no acute stress disorder.     

Prepulse inhibition of startle, intelligence and familial primary nocturnal enuresis

Previous studies have shown a significant reduction of prepulse inhibition of startle in boys with primary nocturnal enuresis. Those enuretic boys who had higher IQs showed less prepulse inhibition. This study evaluates the association of prepulse inhibition and IQ in primary nocturnal enuresis in respect to family history of primary nocturnal enuresis. Prepulse inhibition of startle was studied in 83 boys with primary nocturnal enuresis and 57 non-enuretic boys using an interval of 120 ms between the onset of a 75 dB 1000 Hz tone and a 104 dB noise burst. Of the boys with primary nocturnal enuresis, 56 had a family history of primary nocturnal enuresis and 27 had no family history (no first-degree relative). Of the 57 non-enuretic boys, 42 also had no family history (no first-degree relative) of primary nocturnal enuresis, while 15 did have a positive family history. Associations between prepulse inhibition and IQ scores were compared among these four groups. Strong and significant associations between prepulse inhibition deficit and higher IQ scores in the enuretic group with familial primary nocturnal enuresis were unique in comparison to the other groups. Conclusions: The strong heritabilities of primary nocturnal enuresis, intelligence and prepulse inhibition suggest genetic mediation of the association of prepulse inhibition with intelligence in familial primary nocturnal enuresis.     

Magnetic resonance imaging appearances of the Mirena and GyneFix intra-uterine contraceptive devices: a report of two cases

We report here two cases which illustrate the magnetic resonance imaging (MRI) appearance of the Mirena levonorgestrel releasing intra-uterine system and the GyneFix copper intra-uterine contraceptive implant. The MRI appearance of these devices has not to our knowledge been reported to date, and as increasing numbers of women choose to use these devices for treatment of gynaecological conditions and contraception, it becomes increasingly important to recognise their appearance on pelvic imaging.     

Congenital thiopurine methyltransferase deficiency and 6-mercaptopurine toxicity during treatment for acute lymphoblastic leukaemia

Two children with acute lymphoblastic leukaemia (ALL) taking daily 6-mercaptopurine as part of a national UK therapeutic trial repeatedly developed profound myelosuppression on 25% of the standard protocol dose. Both were found to have undetectable intracellular activity of thiopurine methyltransferase (TPMT), an enzyme controlling one of the major alternative catabolic pathways of 6-mercaptopurine, and both produced higher concentrations of cytotoxic drug metabolites at 10-25% of the protocol dose than other patients taking 100%. It is supposed that these patients represent the 0.33% of the normal population constitutionally lacking TPMT. It is important to recognise such individuals both to avoid fatal bone marrow failure through inadvertent overdosage, and to be reassured that an adequate drug effect can be achieved at around 10% of the standard dose.