Anterior interbody fusion of the lumbar spine

Anterior interbody fusion of the lumbar spine by the extraperitoneal technique was performed in 47 patients with incapacitating low-back pain due to spondylolisthesis (26 patients) or disc degeneration (21 patients). The mean age was 38.2 years. Forty-five patients were re-examined 2--6 years postoperatively. According to the patients' own evaluation at follow-up, 53 per cent were free or almost free of back pain, 29 per cent were improved, 11 per cent unchanged and 7 per cent felt that the condition had deteriorated. Non-union occurred in nine patients, but among these three were free of pain, four were better and two were worse than before operation. The results do not seem to be correlated with age, sex, duration of pain before operation, degree of slipping in spondylolisthesis or the length of time out of work before surgery. It is concluded that this method may be worth continuing, but the patients should be selected with care.     

Muscle autoantibodies in subgroups of myasthenia gravis patients

Myasthenia gravis (MG) is caused by autoantibodies to the acetylcholine receptor (AChR), but several other muscle autoantibodies have also been identified in patient sera. We studied muscle autoantibodies against AChR, striated muscle tissue sections (SH), titin, citric acid antigen (CA), and ryanodine receptor (RyR) in sera from 146 consecutive MG patients to evaluate whether a single test or several tests together can predict a thymoma. The MG patients were divided into five subgroups; ocular MG, early-onset MG (< 50 years), late-onset MG (≥ 50 years), MG with thymoma, and AChR antibody negative MG. AChR, SH, titin, CA, and RyR antibodies were detected in 85%, 34%, 34%, 25%, and 14% of the MG patients, respectively. For thymoma MG, AChR, SH, titin, CA, and RyR antibodies were detected in 100%, 75%, 95%, 70%, and 70% respectively. SH, titin, CA, RyR antibodies, and computed tomography of the anterior mediastinum have similar sensitivity for thymoma MG. The specificity of RyR, titin, CA, and SH antibodies for thymoma was 70%, 39%, 38%, and 31%, respectively, which is significantly higher for RyR antibodies than for the others. No single muscle antibody assay can predict a thymoma, and a combination of several antibody assays is preferred, although RyR antibody testing alone showed 70% sensitivity and specificity for thymoma MG. SH and CA antibodies provided only little additional information. Received: 23 September 1999, Received in revised form: 6 December 1999, Accepted: 19 January 2000     

Infant Sleep Predicts Attention Regulation and Behavior Problems at 3–4 Years of Age

This longitudinal study assessed the role of early sleep patterns in predicting attention regulation and behavior problems. Sleep of 43 infants was assessed using actigraphy at 12 months of age and then reassessed when the children were 3–4 years old. During this follow-up, their attention regulation and behavior problems were also assessed using a computerized test and parental reports. Lower quality of sleep in infancy significantly predicted compromised attention regulation and behavior problems. These findings underscore the need to identify and treat early sleep problems.     

Climate forcing from the transport sectors

Although the transport sector is responsible for a large and growing share of global emissions affecting climate, its overall contribution has not been quantified. We provide a comprehensive analysis of radiative forcing from the road transport, shipping, aviation, and rail subsectors, using both past- and forward-looking perspectives. We find that, since preindustrial times, transport has contributed approximately 15% and 31% of the total man-made CO2 and O3 forcing, respectively. A forward-looking perspective shows that the current emissions from transport are responsible for approximately 16% of the integrated net forcing over 100 years from all current man-made emissions. The dominating contributor to positive forcing (warming) is CO2, followed by tropospheric O3. By subsector, road transport is the largest contributor to warming. The transport sector also exerts cooling through reduced methane lifetime and atmospheric aerosol effects. Shipping causes net cooling, except on future time scales of several centuries. Much of the forcing from transport comes from emissions not covered by the Kyoto Protocol.     

Traumatic injuries of the teeth in connection with general anaesthesia and the effect of use of mouthguards

The aim of the present study was to describe the frequency of dental injuries over a 10-year period, where a mouthguard was used in approximately 10% of intubation cases or endoscopying. The types of injury are presented and the use of different types of mouthguard is discussed. Among 120,086 procedures involving anaesthesia carried out in the period 1983-1992 at Bispebjerg Hospital, Copenhagen, 75 cases of dental trauma occurred. The incidence of dental traumatic injuries was 0.06%. Although eight patients had used mouthguards they were registered with traumatic injuries to the teeth in connection with general anaesthesia. Of the patients, 58% were women and 42% men, with a mean age of 61 years. Seventy-eight percent of the injuries were located in the maxilla and 91% of these involved the incisor area of the maxilla. Forty-one percent were classified as lateral luxations or mobile teeth, 47% were classified as fractured teeth, 10% tooth avulsions and the remaining 2% were classified as concussions. Because of the low frequency of traumatic dental injuries in connection with general anaesthesia and the non-significant effect of the use of mouthguards, routine use of mouthguards is not recommended. Only when a patient is to have an endoscopy done under general anaesthesia, and the surgeon or anaesthesiologist foresees problems (restricted mouth opening, extensive fixed prosthetics, extensive loss of marginal bone) is use of an individually made mouthguard indicated.     

Vitamin D, insulin secretion, sensitivity, and lipids: results from a case-control study and a randomized controlled trial using hyperglycemic clamp technique

OBJECTIVE

Vitamin D deficiency is associated with an unfavorable metabolic profile in observational studies. The intention was to compare insulin sensitivity (the primary end point) and secretion and lipids in subjects with low and high serum 25(OH)D (25-hydroxyvitamin D) levels and to assess the effect of vitamin D supplementation on the same outcomes among the participants with low serum 25(OH)D levels.

RESEARCH DESIGN AND METHODS

Participants were recruited from a population-based study (the Tromsø Study) based on their serum 25(OH)D measurements. A 3-h hyperglycemic clamp was performed, and the participants with low serum 25(OH)D levels were thereafter randomized to receive capsules of 20,000 IU vitamin D₃ or identical-looking placebo twice weekly for 6 months. A final hyperglycemic clamp was then performed.

RESULTS

The 52 participants with high serum 25(OH)D levels (85.6 ± 13.5 nmol/L [mean ± SD]) had significantly higher insulin sensitivity index (ISI) and lower HbA_1c and triglycerides (TGs) than the 108 participants with low serum 25(OH)D (40.3 ± 12.8 nmol/L), but the differences in ISI and TGs were not significant after adjustments. After supplementation, serum 25(OH)D was 142.7 ± 25.7 and 42.9 ± 17.3 nmol/L in 49 of 51 completing participants randomized to vitamin D and 45 of 53 randomized to placebo, respectively. At the end of the study, there were no statistically significant differences in the outcome variables between the two groups.

CONCLUSIONS

Vitamin D supplementation to apparently healthy subjects with insufficient serum 25(OH)D levels does not improve insulin sensitivity or secretion or serum lipid profile.Type 2 diabetes is a chronic condition associated with increased risk of micro- and macrovascular morbidity (1). The underlying pathophysiological mechanisms include insulin resistance combined with a relative deficit of insulin secretion from the pancreas, usually accompanied by systemic inflammation (2). The number of people suffering from the disease is increasing globally (2). Effective preventive means are therefore needed, and modifiable risk factors should be identified and explored.Vitamin D insufficiency, which is reported to be highly prevalent (3), might be such a factor. The vitamin D receptor (4) and the enzyme 1-α hydroxylase (5), which is necessary for the production of the active form of the hormone 1,25(OH)₂D (1,25-dihydroxyvitamin D), are present in pancreatic β-cells. Accordingly, vitamin D has been reported to increase glucose-mediated insulin secretion in animal studies (6). In vitro, 1,25(OH)₂D increases the expression of the insulin receptor and enhances insulin-mediated glucose transport (7). Although less explored, the anti-inflammatory effects of vitamin D might also affect diabetes development (8).Consistent with this, observational data from a number of epidemiological studies show an inverse association between serum 25(OH)D (25-hydroxyvitamin D) and glucose levels (9–12), insulin resistance (11–18), and prevalence of type 2 diabetes (18–20). However, to demonstrate a causal relation between vitamin D and glucose metabolism, evidence from randomized and adequately powered placebo-controlled intervention trials is needed. As recently reviewed, the studies published thus far are heterogeneous regarding dose and formulation of vitamin D treatment, duration, and inclusion criteria; most use indirect measures of insulin secretion and sensitivity; and the results are inconsistent (21).In the sixth Tromsø Study in 2008, serum 25(OH)D was measured in nearly 12,000 subjects. On the basis of these measurements, we invited subjects with low or high serum 25(OH)D levels to a follow-up study where insulin sensitivity and secretion were evaluated with the hyperglycemic clamp technique. Thereafter, the subjects with low serum 25(OH)D levels were invited to a 6-month intervention study to compare the effect of vitamin D₃ 20,000 IU twice per week with placebo on the same measures. As we previously have found cross-sectional and longitudinal associations between serum 25(OH)D levels and serum lipids (22), measurements of serum lipids were also included.     

Chemical genomic profiling for identifying intracellular targets of toxicants producing Parkinson's disease.

The yeast deletion collection includes approximately 4700 strains deleted for both copies of every nonessential gene. This collection is a powerful resource for identifying the cellular pathways that functionally interact with drugs. In the present study, the complete pool of approximately 4700 barcoded homozygous deletion strains of Saccharomyces cerevisiae were surveyed to identify genes/pathways interacting with 1-methyl-4-phenylpyridinium (MPP(+)) and N,N-dimethyl-4-4-bipiridinium (paraquat), neurotoxicants that can produce Parkinson's disease. Each yeast mutant is molecularly "barcoded" the collections can be grown competitively and ranked for sensitivity by microarray hybridization. Analysis data from these screens allowed us to determine that the multivesicular body pathway is an important element of toxicity induced by both MPP(+) and paraquat. When yeast genes that when deleted showed sensitivity to MPP(+) and paraquat toxicity were analyzed for their homology to human genes, 80% were found to have highly conserved human homologs (with e < 10(-8)). Future work will address if these human genes may also functionally interact with MPP(+) and paraquat toxicity.