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Biomedical subjects

D Berg

Publications and source records attributed to D Berg.

At least 19 recordsLinked to original sources

Echogenicity of substantia nigra determined by transcranial ultrasound correlates with severity of parkinsonian symptoms induced by neuroleptic therapy.

BACKGROUND: Increased echogenicity of the substantia nigra (SN) detected by transcranial sonography is a characteristic ultrasound feature of Parkinson's disease. This ultrasound feature can also be detected in a subgroup of healthy adults. In recent studies, healthy subjects with this ultrasound feature showed a reduced [(18)F]-Dopa uptake on positron emission tomography (PET), indicating a subclinical alteration of the nigrostriatal system. This study was designed to evaluate whether the severity of neuroleptic side effects is related to the echo-feature of the SN. METHODS: In the retrospective part of the study, 93 psychiatric patients with either definite and severe parkinsonism after neuroleptic treatment (n = 52) or with no or minimal parkinsonian symptoms (n = 41) were included and underwent transcranial sonography to measure the extension of hyperechogenic areas at the SN. In addition, in the prospective part 11 patients with an acute psychotic episode requiring first-ever neuroleptic treatment underwent ultrasound examination. Subsequently, neuroleptic-induced parkinsonian signs were assessed prospectively. RESULTS: In the retrospective part of the study, patients with severe neuroleptic-induced parkinsonism had more extended echogenic signals at the SN than those with low echogenic SN (U-test; p <.01). The prospective part of the study showed that the severity of parkinsonian symptoms correlated with the echogenicity of the substantia nigra (Spearman's rank: p <.01). CONCLUSIONS: Increased echogenicity of the substantia nigra is associated with impaired function of the nigrostriatal system that can be disclosed by neuroleptic drugs.

Acute Disease↗

Molecular diversity of live-attenuated prototypic vaccine strains and clinical isolates of Staphylococcus aureus.

Bovine mastitis Staphylococcus aureus isolates and prototypic live-attenuated vaccine strains were analyzed by SmaI pulsed-field gel electrophoresis (PFGE) typing and automated ribotyping. The discriminatory index of these methods was 0.91 and 0.69, respectively. SmaI PFGE typing assigned all laboratory strains into cluster Q, which shared 49% similarity with clusters A and B, and 35% similarity with cluster C. Automated ribotyping placed laboratory strains within ribogroups different from those of bovine isolates. These methods have 70% concordance and permitted identification of the prototypic vaccine background from those of clinical isolates. This information is required before conducting field trials with the vaccine.

Animals↗

Management of severe hypokalemia in hospitalized patients: a study of quality of care based on computerized databases.

BACKGROUND: While administrative databases are used to assess general indicators of quality of care, a detailed audit of the process of clinical care usually requires review of hospital medical records. OBJECTIVE: To evaluate the feasibility of assessing the management of severe hypokalemia using computerized administrative and laboratory databases. METHODS: The study included all patients hospitalized in 1997 who experienced serum potassium levels of less than 3.0 mmol/L at Hadassah University Hospital, Jerusalem, Israel, a tertiary care center. Using the computerized databases, we measured the following: (1) whether a subsequent serum potassium test was performed, (2) time to the subsequent test and to normalization of the serum potassium level, (3) achievement of normokalemia, and (4) in-hospital mortality. In a random subsample of 100 patients, these measures were compared with the blinded assessment of the quality of medical management of hypokalemia, as determined from medical records, using predetermined criteria for adequate management. RESULTS: The computerized databases revealed that severe hypokalemia occurred in 866 patients (2.6% of the yearly hospitalizations): 55 patients (6.4%) had no subsequent serum potassium levels measured, and 260 (30.0%) were discharged from the hospital with a subnormal potassium level. The mean time to a subsequent test was 20 hours, and to normokalemia, 50 hours; both intervals varied by department. In-hospital mortality was 20.4%, or 10-fold that of the entire hospitalized population. A review of hospital medical records revealed inadequate clinical management of hypokalemia in 24%, which was associated with nonperformance of a subsequent test (likelihood ratio, 8.4), failure to normalize the serum potassium level (likelihood ratio, 4.2), discharge from the hospital with a subnormal potassium level (likelihood ratio, 2.1), and in-hospital death (likelihood ratio, 2.5), all of which could be determined by the computerized databases. CONCLUSIONS: The computerized laboratory database is useful in ascertaining the prevalence of severe hypokalemia and in assessing shortcomings in its management. Databases can be used to derive valid and efficient measures of the quality of the clinical management of electrolyte disorders.

Clinical Laboratory Information Systems↗

Relationship of substantia nigra echogenicity and motor function in elderly subjects.

BACKGROUND: Patients with Parkinson's disease (PD) exhibit an increased echogenicity of the substantia nigra (SN) on transcranial sonography. Some healthy adults with the same echo characteristics showed a reduced 18fluorodopa uptake on PET, indicating a subclinical alteration of the nigrostriatal system. OBJECTIVES: To determine whether the sonographic phenotype of hyperechogenic SN has any relevance for motor function in elderly subjects and whether an increased echogenicity of the SN is associated with an impaired motor function. METHOD: In a population-based, cross-sectional study, 93 subjects older then 60 years without history of extrapyramidal disorder underwent sonographic and neurologic examinations, with a quantitative motor assessment. RESULTS: Elderly healthy subjects without prediagnosed extrapyramidal disorder but with SN hyperechogenicity had more frequent and more severe parkinsonian symptoms and a slower finger tapping than those with a regular echogenicity of the SN (p < 0.05, U test). CONCLUSION: With increasing age, subjects with SN hyperechogenicity develop a more substantial slowing of movements than subjects without this echo pattern, stressing the functional relevance of this sonographic finding. The authors speculate that hyperechogenicity of the SN may be detected by transcranial sonography early in life and may serve as a risk marker for nigral injury, although only a minority of these subjects will develop the full clinical picture of PD.

Aged↗

Inherited Myoclonus-dystonia syndrome: narrowing the 7q21-q31 locus in German families.

Genetic studies were performed in four German families with autosomal dominant myodonus-dystonia syndrome. Mutations in the D2 dopamine receptor gene, which have been implicated in this disorder, were excluded in all four families by linkage analysis and direct sequencing. All four families supported linkage to the second reported locus on chromosome 7q21 with a combined maximum multipoint lod score of 5.99. The observation of key recombinations in one family refined the disease locus to a 7.2 cM region flanked by the markers D7S652 and D7S2480.

Adolescent↗

Neuroimaging in basal ganglia disorders: perspectives for transcranial ultrasound.

Transcranial sonography is a new diagnostic tool, allowing not only the evaluation of cerebral arteries but also the two-dimensional display of the brain parenchyma. In this review we will summarize basics of the application, the ultrasound anatomy of the brain and sonographic findings in some movement disorders. While in normal adults basal ganglia nuclei are hypoechogenic, they are hyperechogenic in certain basal ganglia disorders. In Parkinson's disease, for example, the substantia nigra can be depicted as a distinctly echogenic area. An elevated echogenicity of the lentiform nuclei was noticed in patients with primary adult-onset dystonia. In both disorders the altered echogenicity may arise from higher heavy metal tissue content (i.e. iron in Parkinson's disease and copper in primary dystonia). Our findings converge to the hypothesis that transcranial ultrasound sensitively detects pathological metal accumulation not identified by other neuroimaging techniques (CT and MRI) and therefore provides new insights in the diagnosis of basal ganglia disorders. The implications of these findings for the understanding of the pathogenesis and its usefulness for the early diagnosis of movement disorders are outlined.

Basal Ganglia Diseases↗

Echogenicity of the substantia nigra in Parkinson's disease and its relation to clinical findings.

Recently an increased echogenicity of the substantia nigra (SN) in patients with Parkinson's disease (PD) was demonstrated by transcranial ultrasound (TCS). In this study we set out to compare SN echogenicitiy with disease characteristics (time of onset, duration, toxin exposure) in a large patients sample. Patients' history and exposure to toxins were recorded from 112 PD patients who underwent a thorough neurological examination including assessment of disease stage according to Hoehn and Yahr and CURS (Columbia University Rating Scale). Personality was assessed according to the Freiburg Personality Inventory. In all patients the area of SN echogenicity was encircled and measured by TCS. All except 9 patients had hyperechogenic SN areas exceeding the mean plus standard deviation values of an age matched control group (0.19 cm2). The age of disease onset was lower in patients who displayed an area of SN echogenicity above this value. The area of SN echogenicity was larger contralateral to the side with more severe symptoms. None of the other characteristics correlated with ultrasound findings. We conclude that SN hyperechogenicity is a typical finding in PD. The cause of hyperechogenicity is so far unknown. Investigation of the underlying reason might disclose a pathogenic factor in PD.

Aged↗

Cerebral activation patterns in patients with writer's cramp: a functional magnetic resonance imaging study.

Functional MRI (fMRI), visualizing changes in cerebral blood oxygenation, has to date not been performed either in patients with writer's cramp or in healthy subjects during writing. We compared the cerebral and cerebellar activation pattern of 12 patients with writer's cramp during writing with a group of 10 healthy subjects performing the same tasks over 30-s periods of rest or writing. Sixty echo planar imaging multislice datasets were analysed using SPM96 software. Data were analysed for each subject individually and groupwise for patients vs. controls. Healthy subjects showed a significant activation of the ipsilateral dentate nucleus, contralateral cerebellar hemisphere, contralateral primary sensorimotor cortex, and contralateral precentral gyrus during writing. Patients with writer's cramp showed significantly greater activation of the ipsilateral cerebellar hemisphere than controls. Also the activation in the primary sensorimotor cortex extended further caudally and anteriorly towards the premotor association area. Activation was observed in the thalamus during writing only among the patients. Our results indicate an increased basal ganglia output via the thalamus to the motor and premotor cortical areas in dystonia patients and support the notion of disinhibition of the motor cortex leading to cocontractions and dystonic postures.

Adult↗

Boost irradiation of breast carcinoma: teletherapy vs. brachytherapy.

BACKGROUND: The results of adjuvant radiotherapy including a boost dose after breast-conserving surgery of mamma carcinoma were retrospectively analysed to relate local tumor control, survival, and cosmetic results to the boost technique. MATERIAL AND METHODS: The study included 229 female patients who were treated in the period 1986--1997. Group A consisted of patients where the primary irradiation was hyperfractionated (two fractions per day) and the boost was applied by reduced portals, also at two fractions per day. In group B the 'boost' was applied interstitially intraoperatively and the 'primary' irradiation followed at one fraction per day. The cosmetic results and the late changes to the mamma were the subjects of follow-up examinations and were assessed using the EORTC score. RESULTS: 129 patients formed group A, median follow-up 4.2 years, and 100 patients with median follow-up of 9.4 years formed group B. 59% of group A and 60% of group B were in stage pT1, 38% and 39% were in pT2, and 25% and 39% were in stage N1 or N2 (no significant differences). Tumors were mostly poorly to moderately differentiated. The upper outer quadrant was most afflicted. Local recurrence occurred in two and five cases, lymph-node recurrence in two cases each, while there were ten and 12 cases of distant metastases. There were no deaths in group A and in group B six with obvious distant metastases and eight with other causes of death. The cosmetic results and late side-effects (induration, teleangiectasis, ulcers) were significantly worse in the interstitial group B. Multivariate analysis revealed that only the total applied dose significantly affected the severity of late radiation side-effects. The cosmetic results worsened with time, the tendency for lymph edemas in the irradiated side increased. Induration decreased continuously after pure teletherapy but increased continuously after interstitial therapy. These trends did not change in either group. CONCLUSIONS: Both therapy schemes resulted in successful local tumor control with good cosmetic results and few side effects, but the interstitial boost therapy was clearly less favourable. Longer-term follow-up is required to compare the late side-effects even further.

Adult↗

Genotypic analysis of Staphylococcus aureus from milk of dairy cows with mastitis in Argentina.

Staphylococcus aureus is the most prevalent pathogen causing mastitis of dairy ruminants. This study was developed to ascertain the genotypes and genealogical relationship among strains isolated from milk of bovines with mastitis in Argentina. Molecular epidemiological analysis of S. aureus was performed on 112 isolates from 21 districts. Clonality was assessed by SmaI pulsed-field gel electrophoresis (PFGE) typing, automated EcoRI ribotyping and restriction enzyme analysis of plasmid (REAP) DNA profiles. A total of 22 band patterns distributed in four clusters were found by SmaI PFGE analysis. The similarity of clusters 2, 3 and 4 with cluster 1 was 0.73, 0.69 and 0.33, respectively, and 101 of 112 isolates belonged in cluster 1. PFGE band patterns from 42 isolates within cluster I were indistinguishable from each other (type A). The second largest group of isolates with indistinguishable PFGE band patterns was subtype A11, which was composed of 19 isolates. Automated ribotyping assigned the 112 isolates into 13 ribotypes. Among these, the most prevalent ribotypes I and VI were composed of 49 and 35 isolates respectively. Although there was certain correspondence between PFGE genotypes and ribotypes, further discrimination was achieved by combining both methods. REAP DNA profile analysis was useful to provide even further discrimination between isolates with identical PFGE genotype and ribotype. The most prevalent S. aureus strains A/I and A11/VI were widely distributed in the country and were not restricted to individual nearby locations. Prevalence of these two strains varied consecutively within a period of 8 years. Whether the shift in type prevalence was due to selection of a phenotypic trait remains undisclosed.

Animals↗

Basal limbic system alteration in major depression: a hypothesis supported by transcranial sonography and MRI findings.

The pathogenesis of major depression (MD) remains unclear despite intensive research in the last decades which brought up a multitude of findings illustrating the complexity of this disorder. In this paper we will summarize the evidence pointing towards a structural alteration of the basal limbic system in MD and depression in Parkinson's disease (PD). Transcranial ultrasound and MRI studies in both depressive syndromes revealed altered signal intensity of the brainstem midline comprising fibre tracts of the basal limbic system. The hypothesis of a structural disruption of the basal limbic system is supported by biochemical and histopathological findings. The similarity of findings in MD and depression in PD might reflect a relationship between MD and neurodegenerative disorders.

Brain Stem↗

Quality of life in patients with blepharospasm.

OBJECTIVES: Administration of botulinum neurotoxin A (BONT/A) is a common and effective treatment of blepharospasm. There is, however, no information regarding the emotional and social well-being of patients with blepharospasm and patient acceptance of BONT/A therapy. The purpose of this study was to investigate aspects of quality of life of patients with blepharospasm and level of patient satisfaction with treatment. MATERIAL AND METHODS: Fifty-one patients with blepharospasm who had been treated with BONT/A for years completed a questionnaire providing information about quality of life. RESULTS: Results revealed reductions in social and emotional well-being of patients but, nonetheless, good acceptance of BONT/A therapy. The positive effects of BONT/A therapy were, however, accompanied by fear of a decreasing effect of BONT/A injections. CONCLUSION: Although the objective findings following BONT/A injections in the treatment of blepharospasm are appreciated by the patients, their well-being is affected by fears and depression.

Aged↗

Mutations in the gene encoding epsilon-sarcoglycan cause myoclonus-dystonia syndrome.

The dystonias are a common clinically and genetically heterogeneous group of movement disorders. More than ten loci for inherited forms of dystonia have been mapped, but only three mutated genes have been identified so far. These are DYT1, encoding torsin A and mutant in the early-onset generalized form, GCH1 (formerly known as DYT5), encoding GTP-cyclohydrolase I and mutant in dominant dopa-responsive dystonia, and TH, encoding tyrosine hydroxylase and mutant in the recessive form of the disease. Myoclonus-dystonia syndrome (MDS; DYT11) is an autosomal dominant disorder characterized by bilateral, alcohol-sensitive myoclonic jerks involving mainly the arms and axial muscles. Dystonia, usually torticollis and/or writer's cramp, occurs in most but not all affected patients and may occasionally be the only symptom of the disease. In addition, patients often show prominent psychiatric abnormalities, including panic attacks and obsessive-compulsive behavior. In most MDS families, the disease is linked to a locus on chromosome 7q21 (refs. 11-13). Using a positional cloning approach, we have identified five different heterozygous loss-of-function mutations in the gene for epsilon-sarcoglycan (SGCE), which we mapped to a refined critical region of about 3.2 Mb. SGCE is expressed in all brain regions examined. Pedigree analysis shows a marked difference in penetrance depending on the parental origin of the disease allele. This is indicative of a maternal imprinting mechanism, which has been demonstrated in the mouse epsilon-sarcoglycan gene.

Adolescent↗

Virtual reality simulators for dermatologic surgery: measuring their validity as a teaching tool.

Surgical simulation is increasingly being considered for training, testing, and possibly credentialing in medicine and surgery. At the University of Washington we have been developing a virtual reality (VR) suturing simulator. In the course of development it must be realized that expensive new technologies should bear the burden of proof of their effectiveness and reliability before they are put into training programs. The purpose of this article is to define the concept of surgical skill and to discuss how it can be measured in the context of validating VR surgical simulators. Specific measures of validity and reliability are reviewed and discussed.

Computer Simulation↗

Evidence-based medicine for dermatologic surgeons: concepts in critical appraisal of information.

BACKGROUND: The term evidence-based medicine (EBM) is increasingly being used. Physicians, journal editors, insurance companies, and patients are applying its tenets to clinical decision making. Although there are concerns about the overly zealous application of EBM to clinical situations, many of the basic concepts are important in improving decision making. OBJECTIVE: To define evidence-based medicine and to review potential problems in basing decision making entirely on less-than-ideal evidence. METHODS: We reviewed the EBM literature and looked for examples in dermatology of pitfalls in decision making based on poor evidence. RESULTS: Following a definition of EBM, we review problems inherent in anecdotes and uncontrolled trials, including the placebo effect. Examples of medical practice that have been altered by doing more rigorous studies are provided. CONCLUSIONS: Concepts of EBM as currently defined should be considered by dermatologic surgeons in assessing the available information for clinical decision making.

Clinical Trials as Topic↗

Fungal skin infections in children. New developments and treatments.

Recognizing the common manifestations of pediatric fungal infections is a key part of any primary care practice. Of paramount importance is the clinical acumen of the physician. In this article, Drs Berg and Erickson discuss several types of fungal infections in children, identify tools for diagnosis, and outline the most effective options for treatment. Newer "off-label" therapies are also examined.

Administration, Cutaneous↗

Reduction of Menkes mRNA and copper in leukocytes of patients with primary adult-onset dystonia.

Studies on postmortem tissue of patients with primary adult-onset dystonia revealed a significant increase in copper levels and a reduction of copper transporting Menkes protein of the lentiform nuclei. Here we demonstrate that patients with idiopathic adult-onset cervical dystonia (n = 14) have reduced Menkes mRNA copies and lower copper levels in leukocytes compared to controls (n = 17; U test, p < 0.05). Changes were less distinct in patients with blepharospasm. Therefore, disturbances of copper metabolism in focal dystonia may not be restricted to the basal ganglia.

Adenosine Triphosphatases↗