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Maier W, Ridder GJ, Arndt S, Schipper J. Funktionelle Reanimation des Nervus facialis nach Schädelbasischirurgie durch die Ansa nervi hypoglossi–Methode und Ergebnisse. Laryngorhinootologie 2004. [DOI: 10.1055/s-2004-823759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Fuchs S, Rolauffs B, Arndt S, Tibesku CO, Prehm P. CD44H and the isoforms CD44v5 and CD44v6 in the synovial fluid of the osteoarthritic human knee joint. Osteoarthritis Cartilage 2003; 11:839-44. [PMID: 14629959 DOI: 10.1016/j.joca.2003.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine whether the concentrations of CD44H and v5 and v6 in the synovial fluid are correlated with the presence of accompanying synovitis in the osteoarthritic joint and with the grade of osteoarthritis. DESIGN Using antero-posterior and lateral X-rays of the knee joint and patellar view of 46 patients were graded with the Kellgren & Lawrence scale. Synovial fluid from these patients with different grades of primary osteoarthritis of the knee joint with and without synovial inflammation (synovitis) was collected during surgical procedures. A horseradish peroxidase conjugated anti-CD44H-, anti-sCD44v5- or anti-sCD44v6-antibody was added and labeled with tetramethylbenzidine. The absorbance was measured at wavelengths of 450/620 nm. Regression analysis was performed and the statistical significance was assessed, using the Student t-test for unequal variance. RESULTS CD44H and v5 and v6 were detected in the synovial fluid of all 46 patients. Osteoarthritic patients with synovial inflammation showed significantly higher levels of CD44H and v6, but not v5, than osteoarthritic patients without synovial inflammation. With progression of osteoarthritis from Kellgren grade II to III, CD44v5 decreased significantly. All other isoform concentrations remained statistically unchanged. CONCLUSIONS CD44H and the isoforms v5 and v6 were present in the synovial fluid of osteoarthritic patients. Their concentrations do not reflect the osteoarthritic stage in the Kellgren grading scale. CD44H and CD44v6, but not CD44v5, are significantly up-regulated in osteoarthritic synovial inflammation.
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Lane AB, Soodyall H, Arndt S, Ratshikhopha ME, Jonker E, Freeman C, Young L, Morar B, Toffie L. Genetic substructure in South African Bantu-speakers: evidence from autosomal DNA and Y-chromosome studies. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2002; 119:175-85. [PMID: 12237937 DOI: 10.1002/ajpa.10097] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The extent of genetic differentiation between seven South African Bantu-speaking groups (Zulu, Xhosa, Tsonga/Shangaan, Southern Sotho, Pedi, Tswana, and Venda) was assessed from coancestry coefficients (F(ST)) estimated from autosomal serogenetic, DNA, and Y-chromosome DNA haplotypes. The overall F(ST) obtained from the autosomal data was 0.002, and that from the Y chromosome data was 0.014. The genetic relationships between groups examined were inferred from their cluster affinities in phylogenetic trees constructed from the genetic distances between them. Both autosomal and Y-chromosome DNA studies reveal that 6 of the 7 South African Bantu-speaking groups cluster according to their linguistic groupings, the exception being the Tsonga, who do not cluster with other Nguni language speakers, but rather with the Venda who live close to them. This suggests that the invading Shangaan-speakers, whose Nguni language was adopted by the Tsonga, did not have a major effect on the Tsonga gene pool, and that gene flow from the Venda into the Tsonga may have been considerable. Genetic distances were found to correlate with geographic distances between the regions where each group's apparent population density is the highest. Linguistic distances were also found to correlate with genetic distances, but linguistic and geographic distances showed no correlation. Together, these results suggest that linguistic and some genetic differentiation took place before the groups (or their forerunners) reached their present-day locations, and that further genetic change occurred after their arrival.
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Frean J, Arndt S, Spencer D. High rate of Bartonella henselae infection in HIV-positive outpatients in Johannesburg, South Africa. Trans R Soc Trop Med Hyg 2002; 96:549-50. [PMID: 12474487 DOI: 10.1016/s0035-9203(02)90437-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The emerging opportunistic pathogen Bartonella henselae has a wide range of clinical presentation, which includes, particularly, bacillary angiomatosis. This non-random pilot survey of outpatients attending HIV clinics in Johannesburg, South Africa, sampled 188 patients, in whom there was a 10% prevalence of Bartonella bacteraemia, as determined by nested polymerase chain reaction.
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Arndt S, Schacht P, Bergt S, Reinmuth J, Millahn K, Keysser M. [Weight loss, arterial hypotension and severe hypoglycemia in a 29-year-old patient with type 1 diabetes mellitus]. Internist (Berl) 2002; 43:410-3. [PMID: 11963724 DOI: 10.1007/s001080100403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Lund BC, Perry PJ, Brooks JM, Arndt S. Clozapine use in patients with schizophrenia and the risk of diabetes, hyperlipidemia, and hypertension: a claims-based approach. ARCHIVES OF GENERAL PSYCHIATRY 2001; 58:1172-6. [PMID: 11735847 DOI: 10.1001/archpsyc.58.12.1172] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Numerous case reports have linked clozapine to the development of diabetes mellitus and hyperlipidemia in patients with schizophrenia. However, investigators have been unable to clearly demonstrate this association when compared with a control group receiving conventional antipsychotics. METHODS Medical and pharmacy claims from the Iowa Medicaid program were used to compare incidence rates for diabetes, hyperlipidemia, and hypertension in 552 patients receiving clozapine and 2461 patients receiving conventional antipsychotics (eg, haloperidol, chlorpromazine hydrochloride), with the use of a retrospective cohort design. Logistic regression was used to compare incidence rates adjusting for age, sex, and duration of available follow-up. RESULTS No significant differences in overall incidence rates for diabetes, hyperlipidemia, or hypertension were observed in patients receiving clozapine vs conventional antipsychotics. However, among younger patients (aged 20-34 years), clozapine administration was associated with a significantly increased relative risk of diabetes (2.5 [95% confidence interval, 1.2-5.4]) and hyperlipidemia (2.4 [95% confidence interval, 1.1-5.2]), but not hypertension (0.9 [95% confidence interval, 0.4-2.0]). CONCLUSIONS These data suggest that clozapine may not be an independent cause of diabetes or hyperlipidemia, but instead acts as an effect modifier in susceptible populations by increasing weight or affecting insulin secretion and resistance. This finding requires confirmation in other settings and patient populations and with the other atypical antipsychotics (risperidone, olanzapine, and quetiapine fumarate). The potential long-term medical and economic implications of the early induction of diabetes and hyperlipidemia in patients with schizophrenia warrant further study.
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Rajarethinam R, DeQuardo JR, Miedler J, Arndt S, Kirbat R, Brunberg JA, Tandon R. Hippocampus and amygdala in schizophrenia: assessment of the relationship of neuroanatomy to psychopathology. Psychiatry Res 2001; 108:79-87. [PMID: 11738542 DOI: 10.1016/s0925-4927(01)00120-2] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The hippocampus and amygdala are believed to be involved in the pathology of schizophrenia. In this study, we attempted to replicate the reported bilateral volume reduction of the hippocampus and amygdala and to study the relationship of the volumes of these structures to the symptoms of schizophrenia. The hippocampus-amygdala complex (HAC) was manually traced on 3-mm coronal T(1)-weighted MRIs, resampled into 1-mm coronal slices, from 20 male patients with schizophrenia and 20 age-matched male controls. The complex was divided into three parts: anterior one-third representing the amygdala and middle and posterior thirds representing the anterior and posterior halves of the hippocampus. Positive and negative symptoms and severity of hallucinations and thought disorder (conceptual disorganization) were quantified using the Brief Psychiatric Rating Scale (BPRS). None of the above structures, controlled for brain volume, differed significantly in patients compared with normal controls. When the relationship between volumes and symptoms was examined, the left HAC was found to inversely correlate with thought disorder and negative symptoms. Specifically, significant inverse correlations were found between (i) left amygdala and thought disorder, (ii) left hippocampus and negative symptoms, and (iii) left anterior and posterior hippocampus volumes and positive and negative symptoms, respectively. Our findings further support the role of the HAC in the pathophysiology of schizophrenia and suggest unique associations between individual structures and specific symptoms of the illness.
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Chen Z, Coffin CM, Smith LM, Issa B, Arndt S, Shepard R, Brothman L, Stratton J, Brothman AR, Zhou H. Cytogenetic-clinicopathologic correlations in rhabdomyosarcoma: a report of five cases. CANCER GENETICS AND CYTOGENETICS 2001; 131:31-6. [PMID: 11734315 DOI: 10.1016/s0165-4608(01)00485-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children younger than the age of 15 years. Histologically, RMS can be subdivided into two major subtypes; embryonal (E-RMS) and alveolar (A-RMS) rhabdomyosarcoma, with E-RMS being the more common. Although cytogenetic and molecular genetic findings have been reported extensively for RMS, clinicopathologic-genetic correlations among these tumors have not been reported in detail. In this report, we correlate the cytogenetic findings, including fluorescence in situ hybridization and spectral karyotyping, with pathologic findings and outcome for five RMS, including two A-RMS, one E-RMS, one botryoid RMS, and one anaplastic nonclassified RMS (N-RMS). The findings in A-RMS and E-RMS generally were consistent with previous reports; however, gain of chromosome 7 in A-RMS and gain of chromosome 9 segments in E-RMS observed here have seldom been reported in the literature. Importantly, the botryoid RMS had a cytogenetic profile similar to other types of E-RMS. An add(11)(q21) observed in this tumor, together with a t(8;11)(q12 approximately 13;q21) reported previously, indicates that 11q21 rearrangements may be nonrandomly related to botryoid RMS. In addition, the N-RMS expressed a cytogenetic pattern similar to that observed in E-RMS, thus providing genetic evidence that anaplastic N-RMS is a variant of E-RMS. Finally, these cases provide cogent evidence for the diagnostic and prognostic significance of the pathologic-genetic classification of RMS.
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Kuperman S, Perry PJ, Gaffney GR, Lund BC, Bever-Stille KA, Arndt S, Holman TL, Moser DJ, Paulsen JS. Bupropion SR vs. methylphenidate vs. placebo for attention deficit hyperactivity disorder in adults. Ann Clin Psychiatry 2001; 13:129-34. [PMID: 11791949 DOI: 10.1023/a:1012239823148] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Despite the increasing recognition of attention-deficit hyperactivity disorder (ADHD) in adults, there are few controlled trials demonstrating the effectiveness of pharmacological treatments, particularly with nonstimulants. One controlled trial found bupropion SR more effective than placebo in the treatment of ADHD adults. We conducted a controlled study to contrast the effectiveness of bupropion SR and methylphenidate to placebo in ADHD adults. A randomized, double-blind, parallel design was used in this study. Following a 7-day placebo lead-in, 30 ADHD (DSM-IV) subjects (18-60 years old) were randomized to bupropion, methylphenidate, or placebo for 7 weeks. Methylphenidate was titrated over 1 week to a maximum dose of 0.9 mg/kg/d divided into 3 doses while bupropion was titrated over 2 weeks to a maximum dose of 200 mg A.M. and 100 mg P.M. Response rates based on Clinical Global Impression improvement ratings in patients receiving bupropion, methylphenidate, and placebo were 64, 50, and 27%, respectively. The difference in response rates between active treatment and placebo was not statistically significant (p = 0.14). Neuropsychological testing demonstrated trends favoring drug treatment on measures of immediate recall and verbal fluency. While bupropion SR may be a viable clinical alternative for adults with ADHD, further investigation is needed.
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Coryell W, Arndt S, Turvey C, Endicott J, Solomon D, Mueller T, Leon AC, Keller M. Lithium and suicidal behavior in major affective disorder: a case-control study. Acta Psychiatr Scand 2001; 104:193-7. [PMID: 11531655 DOI: 10.1034/j.1600-0447.2001.00338.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE A number of studies have suggested that lithium may be particularly effective in reducing suicide risks among patients with major affective disorders. The design of many of these studies left them open to biases associated with treatment compliance, however. METHOD Subjects were drawn from a naturalistic, long-term follow-up of patients with major affective disorders. Fifteen who committed suicide while receiving somatotherapy where matched to non-suicidal patients who were similarly receiving somatotherapy at the same point in follow-up. The same procedure was followed for 41 patients who made a serious suicide attempt during follow-up. RESULTS Six (40.0%) of the patients who committed suicide, and eight (53.3%) of their controls, were thought to have been taking lithium in the preceding week. Among attempters and their controls, nine (22.0%) and eight (19.5%), respectively, were taking lithium. CONCLUSION These results do not support previous suggestions that lithium has uniquely antisuicidal properties. Other existing datasets should be explored with this design to establish whether lithium does, or does not, offer special protection against suicide.
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Stephan KE, Magnotta VA, White T, Arndt S, Flaum M, O'Leary DS, Andreasen NC. Effects of olanzapine on cerebellar functional connectivity in schizophrenia measured by fMRI during a simple motor task. Psychol Med 2001; 31:1065-1078. [PMID: 11513374 DOI: 10.1017/s0033291701004330] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND According to current theories, schizophrenia results from altered connectivity in brain circuits for fundamental cognitive operations. Consequently, the poorly understood mechanisms of neuroleptic treatment may be explainable by altered functional interactions within such networks. The 'cognitive dysmetria' model hypothesizes that one key structure in these circuits is the cerebellum. To investigate the effects of olanzapine on cerebellar functional connectivity (CFC), a seed-voxel correlation analysis (SVCA) was used in a functional magnetic resonance imaging (fMRI) study of a simple finger-tapping task. METHODS fMRI scans were obtained from six schizophrenic patients under both drug-free and olanzapine-treated conditions and from a matched control group of six healthy subjects at corresponding time points. SVCAs were performed for anatomically and functionally standardized seed voxels in the anterior cerebellum. SVCA results were then processed by three different randomization analyses. RESULTS The analyses revealed that olanzapine caused widespread changes of CFC, including prominent changes in prefrontal cortex and mediodorsal thalamus. Significant changes in motor structures were found after subtractions within both groups and may thus indicate repetition effects rather than drug effects. Olanzapine 'normalized' the patients' CFC patterns for the right, but not for the left cerebellum. CONCLUSION Even for a simple motor task, olanzapine affects functional interactions between the cerebellum and many non-motor brain regions, including elements of the 'cognitive dysmetria' circuit. Altogether, our findings suggest that olanzapine has a stronger differential effect on neural activity in prefrontal cortex and thalamus than in motor structures.
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Chemerinski E, Robinson RG, Arndt S, Kosier JT. The effect of remission of poststroke depression on activities of daily living in a double-blind randomized treatment study. J Nerv Ment Dis 2001; 189:421-5. [PMID: 11504318 DOI: 10.1097/00005053-200107000-00002] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Poststroke depression has been associated with impaired recovery of activities of daily living (ADL) during the first 2 years after stroke. This study examined the effect of remission of poststroke depression on recovery in ADL in a double-blind randomized treatment study. Based on a semistructured psychiatric exam and DSM-IV diagnostic criteria, a consecutive series of 23 patients who met criteria for major depression (N = 16) or minor depression (N = 7) were selected and randomly assigned to either active treatment (nortriptyline) or placebo. Functional physical (i.e., ADL) impairment was assessed using the Johns Hopkins Functioning Inventory (JHFI). Patients whose depressive disorder remitted at follow-up had significantly greater recovery in ADL functions compared with patients whose depression did not remit. There were no differences in demographic variables, lesion characteristics, and neurological symptoms between the two groups, which would explain the significantly greater improvement among the remitted patients. Because both major and minor depression patients who remitted showed greater improvement in ADL than nonremitted patients some of whom were treated with active and some with placebo medication, nonpharmacotherapeutic mechanisms related to recovery from depression appear to mediate this enhanced recovery.
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Perry PJ, Lund BC, Arndt S, Holman T, Bever-Stille KA, Paulsen J, Demers LM. Bioavailable testosterone as a correlate of cognition, psychological status, quality of life, and sexual function in aging males: implications for testosterone replacement therapy. Ann Clin Psychiatry 2001; 13:75-80. [PMID: 11534928 DOI: 10.1023/a:1016663523579] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Andropause is a syndrome described in aging males, is composed of a constellation of physical, sexual, and emotional symptoms, and is thought to be related to declining concentrations of serum testosterone. Numerous studies of testosterone replacement therapy in elderly hypogonadal males have documented the physical benefits of such treatment, but have failed to assess cognition, psychological functioning, and quality of life. Male outpatients greater or equal to 55 years of age completed cognitive, psychological, sexual, and quality of life assessments. A serum sample was provided for bioavailable testosterone assay. The associations between bioavailable testosterone concentrations and neuropsychological testing were assessed using Spearman rank correlation. Overall, bioavailable testosterone was not an important determinant of cognitive, psychological, or sexual functioning or of quality of life. The implications for future studies involving testosterone replacement therapy are discussed.
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Turvey CL, Schultz SK, Arndt S, Ellingrod V, Wallace R, Herzog R. Caregiver report of hallucinations and paranoid delusions in elders aged 70 or older. Int Psychogeriatr 2001; 13:241-9. [PMID: 11495398 DOI: 10.1017/s1041610201007621] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This study examined the demographic, medical, and psychiatric correlates of hallucinations and paranoid delusions reported by proxy informants for 822 elders aged 70 or older. This sample comprised people who were deemed unable to complete a direct interview in a large nationwide study of aging. Marital status, trouble with vision, and cognitive impairment were associated with report of both paranoid delusions and hallucinations. Depressive symptoms and stroke were associated with hallucinations only. These results suggest that inadequate external stimulation in the elderly leads to psychotic experiences.
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Moser DJ, Ferneyhough KC, Bauer RM, Arndt S, Schultz SK, Haynes WG, Staples ED, Alexander J, Davies LK, O'Brien DJ. Unilateral vs. bilateral ultrasound in the monitoring of cerebral microemboli. ULTRASOUND IN MEDICINE & BIOLOGY 2001; 27:757-760. [PMID: 11516535 DOI: 10.1016/s0301-5629(01)00381-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We used bilateral transcranial Doppler to monitor the number of microembolic events (ME) in the left and right middle cerebral arteries of 29 patients during cardiac surgery that required extracorporeal circulation. Based on a previously published study, we hypothesized that the commonly used method of doubling unilateral ME counts to obtain an estimated bihemispheric load would result in significant errors of estimation. In our sample, estimated bihemispheric counts were inaccurate by an average of 18% (range 0--80%). Despite this large range of error, calculation of Cronbach's alpha revealed that actual error due to unreliability (4%) was small relative to the large variation in ME counts across subjects in this patient series. These findings suggest that unilateral monitoring is sufficient when the goal is to characterize a given subject's ME load within the context of the other subjects in the sample. However, when precise ME counts are required, bilateral monitoring is essential.
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White T, O'Leary D, Magnotta V, Arndt S, Flaum M, Andreasen NC. Anatomic and functional variability: the effects of filter size in group fMRI data analysis. Neuroimage 2001; 13:577-88. [PMID: 11305887 DOI: 10.1006/nimg.2000.0716] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the analysis of group fMRI scans, an optimal spatial filter should be large enough to accurately blend functionally homologous anatomic regions, yet small enough not to blur the functionally distinct regions. Hanning filters varying from 0.0 to 18.0 mm were evaluated in a group analysis of six healthy controls performing a simple finger-tapping paradigm. Test-retest reliability and Talairach-based measurements of the sensorimotor region were used to explore the optimal filter size. Two distinct regions of functional activation were noted in the sensorimotor cortex in group images (n = 6) at both time 1 and time 2. These regions merge once the filter size exceeds approximately 6.0 mm. The original hypothesis that these represented a motor and sensory activation was rejected on the basis of structural and functional variability. A discussion of the inherent difficulties in choosing an appropriate filter size is presented.
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Coryell W, Fyer A, Pine D, Martinez J, Arndt S. Aberrant respiratory sensitivity to CO(2) as a trait of familial panic disorder. Biol Psychiatry 2001; 49:582-7. [PMID: 11297715 DOI: 10.1016/s0006-3223(00)01089-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND According to three earlier studies, well individuals with a family history of panic disorder experience more anxiety following a single breath of 35% CO(2) than do those without such a family history. This study sought to determine whether a heightened sensitivity to CO(2) manifests specifically in respiratory changes. METHODS Subjects were 18--35 years old and had no history of panic attacks and no current DSM-IV diagnosis other than simple or social phobia. Those at high risk for panic disorder (HR-P) (n = 46) had a first-degree relative with treated panic disorder. Low-risk control subjects (LR-C) (n = 39) had no first-degree relative with panic disorder. Respiratory measurements were taken continuously while subjects breathed room air through an attached mask for 3 min and, subsequently, while they breathed a 5% CO(2)/air mixture for an additional 3 min. RESULTS HR-P subjects did not differ from control subjects by group means of the principal measure of respiratory response, changes in minute volume (MV) during CO(2) inhalation. However, these values assumed clearly different distributions in the two groups. Fifteen (32.6%) of the HR-P subjects showed a paradoxical decrease in MV while breathing CO(2) and six (13%) displayed a particularly rapid increase in MV. Only one (2.6%) of the control subjects had a negative MV slope and none had a high value [chi(2)(1) = 12.3, p <.001, p =.021, Fisher exact test, respectively]. Though the subjects with high MV increases also described greater increases in anxiety after breathing CO(2), a regression analysis indicated that the MV increase was the more important in discriminating high-risk from control subjects. CONCLUSIONS These results suggest that respiratory sensitivity to CO(2) inhalation is operative in the familial transmission of panic disorder.
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Arndt S, Magnotta V. Generating random series with known values of Kendall's tau. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2001; 65:17-23. [PMID: 11223148 DOI: 10.1016/s0169-2607(00)00102-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Kendall's tau(a) offers statistical advantages to the more common Pearson's correlation and both are common in biomedical research. While generating random X-Y pairs from a known population value of Pearson's correlation is straightforward, the process for generating random sequences for a known value of Kendall's tau(a) is more complicated. Algorithms are presented that yield random numbers from a population with a known expected tau(a). They begin with a small set of values that have a known tau. These values are 'grown' to produce an arbitrarily large population that has the same expectation as the smaller set. Two examples are given. One example simulated samples from a population where tau(a) equaled 0.33 and confidence intervals are produced. A second example illustrates how the algorithm can be used to provide statistical power estimates for research studies using Kendall's tau(a).
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Arndt S, Emde U, Bäurle S, Friedrich T, Grubert L, Koert U. Quinone-annonaceous acetogenins: synthesis and complex I inhibition studies of a new class of natural product hybrids. Chemistry 2001; 7:993-1005. [PMID: 11303880 DOI: 10.1002/1521-3765(20010302)7:5<993::aid-chem993>3.0.co;2-s] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The natural product hybrids quinone-mucocin and quinone- squamocin D were synthesized. In these hybrids, the butenolide unit of the annonaceous acetogenins mucocin and squamocin D is exchanged for the quinone moiety of the natural complex I substrate ubiquinone. For both syntheses, a modular, highly convergent approach was applied. Quinone-mucocin was constructed out of a tetrahydropyran (THP) component 1, a tetrahydrofuran (THF) unit 2, and a quinone precursor 3. A stereoselective, organometallic coupling reaction was chosen for the addition of the THP unit to the rest of the molecule. In the final step, the oxidation to the free quinone was achieved by using cerium(IV) ammonium nitrate (CAN) as the oxidizing agent. Quinone-squamocin D was assembled in a similar manner, from the chiral side chain bromide 16, the central bis-THF core 17, and the quinone precursor 18. Inhibition of complex I (isolated from bovine heart mitochondria) by the quinone acetogenins and several smaller building blocks was examined; quinone mucocin and quinone-squamocin D act as strong inhibitors of complex I. These results and the data from the smaller substructures indicate that other substructures of the acetogenins besides the butenolide group, such as the polyether component and the lipophilic left-hand side chain, are necessary for the strong binding of the acetogenins to complex I.
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Philibert RA, Sandhu HK, Hutton AM, Wang Z, Arndt S, Andreasen NC, Crowe R, Wassink TH. Population-based association analyses of the HOPA12bp polymorphism for schizophrenia and hypothyroidism. AMERICAN JOURNAL OF MEDICAL GENETICS 2001; 105:130-4. [PMID: 11424983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
HOPA is an Xq13 chromosome gene that codes for a RXR nuclear receptor co-activator. In a prior study of the genetic basis of schizophrenia, we showed that exonic polymorphisms in HOPA were associated with increased risk of schizophrenia and hypothyroidism in a large cohort of probands from New York. In an attempt to replicate these findings, we examined this relationship in a cohort of 173 schizophrenic probands (128 males and 45 females providing 218 alleles) from Iowa. Consistent with the prior findings, we found an increased rate of the HOPA12bP exonic polymorphism in schizophrenic probands compared with random newborn controls (9 of 218 alleles vs. 33 of 2,049 alleles, P < 0.02). Furthermore, retrospective review of the medical records showed that two of the nine probands possessing the HOPA12bp allele in whom thyroid function was assessed were hypothyroid compared with 6 of 164 probands possessing the normal HOPAwild allele(s) (P < 0.06). We conclude that the HOPA12bp polymorphism shows a nominally significant association with schizophrenia and a nominal trend for association with hypothyroidism in our study and that further studies are required to define the features of this syndrome and the molecular mechanisms of disease pathogenesis.
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Turvey CL, Schultz S, Arndt S, Wallace RB, Herzog R. Memory complaint in a community sample aged 70 and older. J Am Geriatr Soc 2000; 48:1435-41. [PMID: 11083320 DOI: 10.1111/j.1532-5415.2000.tb02634.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVES The ability of older people to estimate their own memory, often referred to as "metamemory," has been evaluated in previous studies with conflicting reports regarding accuracy. Some studies have suggested that an older person's metamemory is mostly accurate, whereas others have demonstrated little relationship between memory complaint and actual impairment. This study examines memory complaint in a large national sample of older people aged > or = 70. DESIGN A longitudinal cohort study with two waves of data collection spaced 2 years apart. SETTING A nationwide random sample of community-dwelling older persons. PARTICIPANTS A total of 5,444 community-dwelling persons aged > or = 70 and their spouses. MEASUREMENTS Participants were asked if they believed their memory was excellent, very good, good, fair, or poor. They were then administered a cognitive assessment derived from the Mini-Mental Status Exam. RESULTS In general, people's assessment of their memory corresponded with their actual performance on cognitive measures. However, large portions of the sample inaccurately assessed their memory skills. People who reported depressive symptoms and had impairment in activities of daily living were more likely to state that their memory was impaired, although they performed very well on cognitive measures. CONCLUSIONS The conditions that skew people's self-assessment are the ones most likely to bring them into contact with healthcare professionals. This may give clinicians the general impression that older people cannot assess their own cognitive skills. However, poor metamemory appears to be a characteristic of a specific subgroup of older persons, not necessarily characteristic of the general population.
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Arndt S, Jorge R, Turvey C, Robinson RG. Adding subjects or adding measurements: Which increases the precision of longitudinal research? J Psychiatr Res 2000; 34:449-55. [PMID: 11165313 DOI: 10.1016/s0022-3956(00)00042-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
When designing repeated measurement studies, researchers must strike a balance between increasing the number of subjects and increasing the number of measurement times for each subject. The question often becomes "Do I gain more statistical precision by adding subjects or by adding additional follow-up measurements?" This study presents a method for evaluating the relative benefit of adding subjects versus adding measurement times. We used the standard error of estimate (SE) for mean change as the criterion of precision. An existing dataset on post-stroke patients containing six follow-up assessments of six standard rating scales was used. SE values for two common change indices were found and compared for all possible two, three, four, five, and six repeated measurements. Sample sizes required to achieve the same benefit as adding an additional measurement are presented. These data suggest that collecting five or six repeated measurements may be sufficient for accurately assessing change and that attempts to further precision should be accomplished by increasing the sample size.
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Abstract
BACKGROUND Substance abuse occurs at high rates in bipolar disorder. The reasons for this co-occurrence are unknown. Alcohol use disorders have been associated with both earlier and later age of onset of bipolar disorder, in part based on the temporal associations of the two conditions. Both drug and alcohol use disorders are associated with impaired outcome of bipolar illness. This influence may involve both direct effects of alcohol or drugs on the initiation of affective symptoms and indirect effects on treatment compliance. To extend these previous findings we examined the temporal associations of substance abuse and affective symptoms in patients with new onset bipolar disorder. METHODS Associations between affective symptoms and alcohol and cannabis use disorder symptoms were evaluated using regression and time-series correlative methods in 50 new-onset bipolar patients. RESULTS The duration of alcohol abuse during follow-up was associated with the time patients experienced depression. The duration of cannabis abuse was associated with the duration of mania. Several subgroups could be identified with different temporal relationships among these disorders. CONCLUSIONS Although the relationships among substance use and bipolar disorders are complex, systematic study of the courses of the disorders might clarify how these conditions interact longitudinally. As the numbers of subjects in specific subgroups are relatively small in this study, these results should be considered preliminary.
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Geracioti TD, Ekhator NN, Nicholson WE, Arndt S, Loosen PT, Orth DN. Intra- and inter-individual correlations between cholecystokinin and corticotropin-releasing hormone concentrations in human cerebrospinal fluid. Depress Anxiety 2000; 10:77-80. [PMID: 10569131 DOI: 10.1002/(sici)1520-6394(1999)10:2<77::aid-da7>3.0.co;2-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Despite strong evidence of a physiologic relationship between cholecystokinin (CCK) and corticotropin-releasing hormone (CRH) in the rat central nervous system (CNS), evidence of such a relationship between the two hormones in the human CNS is lacking. A post hoc analysis of serial concentrations of immunoreactive CCK and CRH, obtained every ten minutes from CSF continuously collected over six hours, was performed. A total of 30 subjects were studied: 15 normal volunteers, 10 patients with major depression, and 5 recently-abstinent, alcohol-dependent patients. Overall, we observed an average intra-subject correlation of +.273 (P < 0.001) between CSF CRH and CCK. Inter-subject correlations between mean CSF levels of CRH and CCK were +.948 (P = 0.0001) and +.959 (P = 0.005) in the depressed and abstinent alcoholic patients, respectively. These inter-individual correlations were significantly greater than that seen within the group of normal volunteers (r = +.318, n.s.). The present data suggest that interactions between CCK and CRH are significant in the human CNS, particularly perhaps in depressed and alcoholic patients, and that CSF samples may be used to assess elements of the relationship between these hormones.
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Adler CM, McDonough-Ryan P, Sax KW, Holland SK, Arndt S, Strakowski SM. fMRI of neuronal activation with symptom provocation in unmedicated patients with obsessive compulsive disorder. J Psychiatr Res 2000; 34:317-24. [PMID: 11104844 DOI: 10.1016/s0022-3956(00)00022-4] [Citation(s) in RCA: 226] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Previous studies suggest that a neural circuit involving over-activation of cortical, paralimbic, limbic, and striatal structures may underlie OCD symptomatology, but results may have been limited by medication use in those studies. To address this, we examined the effects of symptom induction on fMRI neural activation in medication-free patients with OCD. METHODS Seven outpatients with OCD were exposed to individually tailored provocative and innocuous stimuli during fMRI scans. Self-ratings of OCD symptoms were performed prior to each scan and after exposure to stimuli. Images were analyzed as composite data sets and individually. RESULTS Stimulus presentation was associated with significant increases in OCD self-ratings. Significant activation was demonstrated in several regions of the frontal cortex (orbitofrontal, superior frontal, and the dorsolateral prefrontal); the anterior, medial and lateral temporal cortex; and the right anterior cingulate. Right superior frontal activation inversely correlated with baseline compulsion symptomatology and left orbitofrontal cortical activation was inversely associated with changes in OCD self-ratings following provocative stimuli. CONCLUSIONS These results in unmedicated patients are consistent with those from previous studies with medicated patients and suggest that OCD symptomatology is mediated by multiple brain regions including the anterior cingulate as well as frontal and temporal brain regions.
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