Less ethnic knowledge in the Dutch College of General Practitioner's practice guidelines on type 2 diabetes mellitus, hypertension and asthma in adults than in the supporting literature

OBJECTIVE: To assess whether ethnic differences present in the scientific literature used as the basis for the Dutch College of General Practitioner's (NHG) practice guidelines were reflected in the ethnic-specific information the guidelines contained. DESIGN: Analysis of published information. METHOD: The scientific literature used as the basis for the guidelines about type 2 diabetes mellitus, hypertension and asthma in adults was collected and carefully screened. Relevant ethnic-specific information was compared to the content of the guidelines. RESULTS: Several relevant ethnic differences were stated in the scientific literature used as the basis for the guidelines. Differences in prevalence and clinical progress were stated for type 2 diabetes mellitus, differences in lung-volume were stated for asthma and differences in prevalence, onset, complications, response to pharmacological treatment and dietary salt restriction were stated for hypertension. The type 2 diabetes mellitus guideline stated a higher prevalence of diabetes in Hindustani people and recommended earlier screening in this group. The asthma guideline stated that the lung volume is dependent of ethnicity. The hypertension guideline did not state any ethnic-specific information. CONCLUSION: The guidelines on type 2 diabetes mellitus, hypertension and asthma in adults only adopted a limited number of the ethnic differences contained in the scientific literature on which they were based. Possible explanations are that information was only included if there was a clear scientific basis, and that ethnic distinctions were found to be politically and socially undesirable. However, this lack of information might lead to ineffective or sub-optimal care for ethnic minorities.     

Bone homogeneity factor: an advanced tool for the assessment of osteoporotic bone structure in high-resolution magnetic resonance images

RATIONALE AND OBJECTIVES: Osteoporosis is characterized by low bone mass and inferior structural competence. In this study we introduce the bone homogeneity factor (BHF) as a quantitative measurement of bone structure, which could be equally important as bone mineral density. METHODS: BHF represents an advanced texture analysis tool based on the spatial autocorrelation function calculated in 9 different directions. These calculations were performed on high-resolution magnetic resonance images of the calcaneus at 3.0 T and compared with dual-energy x-ray absorptiometry measurements of the femoral neck. RESULTS: The quality and resolution of the high-resolution magnetic resonance images is sufficient for reliably calculating BHF. The mean BHF of the control group (n = 5, mean BHF = 525,0) with normal bone is significantly (P = 0.009, Mann-Whitney U test) higher than in the osteoporotic group (n = 7, mean BHF = 137,8). The BHF correlates with the DXA measurements of the femoral neck (correlation coefficient = 0.75). CONCLUSIONS: By calculating the BHF, it was possible to distinguish between osteoporotic and nonosteoporotic bone structure. Hence, BHF could be a possible candidate for noninvasive assessment of osteoporotic bone structure giving additional information to routinely used bone mineral densitometry.     

Accuracy and reproducibility of manual and semiautomated quantification of MS lesions by MRI

PURPOSE: To evaluate the accuracy, reproducibility, and speed of two semiautomated methods for quantifying total white matter lesion burden in multiple sclerosis (MS) patients with respect to manual tracing and to other methods presented in recent literature. MATERIALS AND METHODS: Two methods involving the use of MRI for semiautomated quantification of total lesion burden in MS patients were examined. The first method, geometrically constrained region growth (GEORG), requires user specification of lesion location. The second technique, directed multispectral segmentation (DMSS), requires only the location of a single exemplar lesion. Test data sets included both clinical MS data and MS brain phantoms. RESULTS: The mean processing times were 60 minutes for manual tracing, 10 minutes for region growth, and 3 minutes for directed segmentation. Intra- and interoperator coefficients of variation (CVs) were 5.1% and 16.5% for manual tracing, 1.4% and 2.3% for region growth, and 1.5% and 5.2% for directed segmentation. The average deviations from manual tracing were 9% for region growth and 5.7% for directed segmentation. CONCLUSION: Both semiautomated methods were shown to have a significant advantage over manual tracing in terms of speed and precision. The accuracy of both methods was acceptable, given the high variability of the manual results.     

Rocuronium and cisatracurium-positive skin tests in non-allergic volunteers: determination of drug concentration thresholds using a dilution titration technique

BACKGROUND: Muscle relaxants are believed to be responsible for 2/3 of the cases of anaphylactic reactions during anesthesia. This assumption is based mainly on positive skin tests obtained in individuals that have experienced anesthesia-related anaphylaxis. A positive skin test is supposed to be associated with mast cell degranulation of vasoactive amines. In the present study we tested the frequency of positive skin tests with two commonly used muscle relaxants, rocuronium and cisatracurium, in a selected group of volunteers with low potential for allergic reactions. METHODS: Thirty healthy volunteers without known allergy or previous exposure to muscle relaxants were studied. Low potential for allergic reactions was determined prior to inclusion in the study, using various allergy tests. Each individual was tested with intradermal and skin prick tests, and molar drug concentration thresholds for positive skin reactions were determined using a dilution titration technique. The presence or absence of mast cell degranulation was tested by electron microscopic investigation of skin biopsies obtained from positive and negative skin reactions. RESULTS: None of the volunteers had a positive skin prick test. More than 90% of the volunteers had a positive intradermal test with both rocuronium and cisatracurium. The highest molar drug concentration that was not associated with a positive intradermal test was 10(-6) M (rocuronium) and 10(-7) M (cisatracurium), equivalent to vial dilution 1 : 1000 for both drugs. In none of the volunteers was mast cell degranulation detected. CONCLUSION: Non-mast-cell-mediated positive intradermal skin reactions are frequently occurring with rocuronium and cisatracurium, even at vial dilution 1 : 1000. A clinically applicable test technique is needed that is able to separate positive skin tests associated with mast cell degranulation from non-mast-cell-mediated reactions.     

An inhibitory function for JNK in the regulation of IGF-I signaling in breast cancer

Insulin-like growth factor-I receptor (IGF-IR) is frequently overexpressed in a variety of cancer types. Since many breast tumors and cancer cell lines overexpress IGF-IR, we tested IGF-I effects on chemotherapy-treated breast cancer cells. IGF-I protects from chemotherapy-induced apoptosis, suggesting that overlapping signaling pathways modulate IGF-I and chemotherapy treatment outcomes. Taxol and other chemotherapy drugs induce c-Jun N-terminal kinase (JNK), a kinase that conveys cellular stress and death signals. Notably, in this paper we show that IGF-I alone induces a potent JNK response and this activity is reversed by inhibition of phosphatidylinositol 3-kinase (PI 3-kinase) with LY294002 in MCF-7 but not T47D cells. Cotreatment of cells with chemotherapy and IGF-I leads to additive JNK responses. Using cells overexpressing Akt, we confirm that IGF-I-mediated survival is Akt dependent. In contrast, overexpression of JNK significantly enhances Taxol-induced apoptosis and inhibits IGF-I survival effects. Further, JNK attenuates anchorage-independent growth of MCF-7 cells. The inhibitory effect of JNK appears to be mediated by serine phosphorylation of IRS-1 (insulin receptor substrate) since both Taxol and IGF-I treatment enhanced Ser(312) IRS-1 phosphorylation, while LY294002 blocked IGF-I-mediated phosphorylation. Taken together, these data provide a mechanism whereby stress or growth factors activate JNK to reduce proliferation and/or survival in breast cancer cells.     

Congenital melanocytic naevi and cutaneous melanoma

Cutaneous melanoma is malignancy with a rapidly increasing incidence and its relationship to congenital melanocytic naevi is unclear. The purpose of this study was to investigate the incidence of congenital melanocytic naevi and the occurrence of cutaneous melanomas in these naevi. We performed epidemiological studies of the Swedish Medical Birth Register and the Swedish Cancer Register, together with a pathohistological review of the cases with congenital melanocytic naevi and cutaneous melanoma. Between the years 1973 and 1993, 3922 congenital melanocytic naevi were registered among 2 198 619 newborns, giving an incidence of 0.2%. Of all the congenital melanocytic naevi registered during the years 1973-1986, 7% were large (146 cases) and 93% were small; 1058 cases had a follow-up time of 15 years or more. Two cases may have been associated with cutaneous melanoma, but pathohistological review revealed no such association. The conclusions are that the incidence of congenital melanocytic naevi is low. We found no relation to cutaneous melanoma, but this could possibly be affected by the removal rate and the length of the follow-up period. Nevertheless, our study does not support the prophylactic removal of all congenital melanocytic naevi and there is no reason to believe that they play a part in the increasing incidence of cutaneous melanoma.     

International medical education between Hawaii and Thailand over Internet2

International medical education sessions have been successfully conducted by videoconferencing using Internet2. The sessions were between two tertiary care medical centres, in Honolulu and Bangkok. However, video quality was lower than for similar sessions using ISDN and audience satisfaction was less. The main reasons for the lower quality were network congestion and bandwidth allocation by the videoconferencing equipment. Software to ensure quality of service is available, but is not easy to implement. There were also network security problems and the costs were high. Our international videoconferences averaged 40-50 hours per year, an activity level at which connection costs were lower for ISDN than for Internet2. It appears that Internet2 videoconferencing for medical education is best reserved for academic institutions that have other high-bandwidth network requirements.     

Remote critical care consultation: telehealth projection of clinical specialty expertise

Remote critical care consultations have been employed between the Naval Hospital in Guam and the Tripler Army Medical Center in Hawaii, a distance of 5300 km. During a 10-week study period there were physician-physician daily consultation rounds for patients in the intensive care unit at the Naval Hospital. Physiological data, video-images and sound were transmitted via a 768 kbit/s frame relay connection, albeit with a 1-3 s delay. During the study there were 87 consultations concerning 25 patients. Preliminary results showed that a broad range of critical care patients could be managed effectively through daily remote critical care consultation. Broader implementation of this strategy may represent a method of making critical care expertise available to front-line military health-care facilities and to remote civilian facilities with limited critical care expertise.     

Does aspirin protect against Alzheimer's dementia? A study in a Swedish population-based sample aged > or =80 years

Objective It has been reported that aspirin and other non-steroidal anti-inflammatory drugs (NSAID) may protect against dementia of Alzheimer's type and/or vascular dementia. However, co-morbidity and the dose of aspirin may be critical. A major indication for low-dose aspirin is prophylaxis after stroke and transient ischaemic attacks, conditions that may obscure an anti-dementia effect by the drug. Alternatively, low-dose aspirin may be insufficient if the protective effect is due to an anti-inflammatory mechanism. The aim of this study was to assess whether high-dose or low-dose aspirin may protect against Alzheimer's dementia in subjects aged 80 years. For comparison, effects of (other) NSAID, paracetamol and d-propoxyphene were studied.Methods Global, cross-sectional, and longitudinal (1991–2000) epidemiological analyses of clinical, cognitive and drug treatment data on 702 individuals 80 years old or more (351 twin pairs of same sex), all alive at inclusion: mean age 83.9 years (80–99 years). Calculations were made with logistic regression of associations between use of various analgesics and cognitive function, after adjustment for age, gender, and cardiovascular and cerebrovascular diseases.Results Users of high-dose aspirin had significantly lower prevalence of Alzheimer's dementia and better-maintained cognitive function than non-users. There were numerically similar but not significant associations with use of low-dose aspirin and other NSAID. There were no such associations with use of either paracetamol or d-propoxyphene.Conclusion Aspirin might protect against Alzheimer's disease, but controlled trials are warranted.