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Biomedical subjects

J C Nelson

Publications and source records attributed to J C Nelson.

At least 73 records · Page 4Linked to original sources
PubMed1997

DST studies in psychotic depression: a meta-analysis.

OBJECTIVE: Although hypersecretion of cortisol has frequently been reported in psychotic depression, the findings have been mixed. The authors performed a meta-analysis of the existing studies to determine the significance of differences in nonsuppression of cortisol across studies. METHOD: Fourteen studies that compared dexamethasone suppression test (DST) results in psychotic and nonpsychotic patients were examined, and a Mantel-Haenszel meta-analysis was performed. For comparison purposes, 19 studies of the DST with respect to melancholic/nonmelancholic and inpatient/outpatient distinctions were similarly reviewed. RESULTS: This analysis indicated a highly significant probability that a greater rate of cortisol nonsuppression occurs in psychotic depression. The nonsuppression rate was substantially higher in patients with psychotic depression (64%) than in nonpsychotic patients (41%). In the 19 studies of melancholia, nonsuppression was less frequent (36%), and when inpatient/outpatient status was controlled, melancholic depression was not significantly associated with nonsuppression. In nonmelancholic outpatients with major depression, the nonsuppression rate was low (12%). CONCLUSIONS: Among patients with major depression, psychotic depression is the subtype that is most closely associated with nonsuppression of cortisol on the DST. Hypercortisolemia is usually present in psychotic depression and may be important in understanding the pathophysiology of this syndrome.

Ambulatory Care↗
PubMed1997

Treatment of dementia with behavioral disturbance using divalproex or a combination of divalproex and a neuroleptic.

BACKGROUND: Neuroleptics have been used extensively to treat noncognitive behavioral disturbances in dementia, although their efficacy is only moderate and side effects are prominent. This study aims to determine the efficacy and tolerability of the non-neuroleptic divalproex sodium in patients with dementia and behavioral problems. METHOD: Charts of consecutive inpatients with dementia and behavioral problems according to DSM-IV were retrospectively reviewed. Patients treated with divalproex were analyzed for dosage, duration of divalproex treatment, levels, efficacy, side effects, and concurrent medications. Target behavioral symptoms were identified, and change was rated using a Clinical Global Impressions (CGI)-Severity of Illness scale. Patients who were much or very much improved were considered to be responders. RESULTS: Twenty-five patients (15 men and 10 women) with a mean+/-SD age of 77+/-7 years were identified. Fourteen (56%) of the 25 patients met our criteria for response after the addition of divalproex. Divalproex given alone was effective in 7 of 15 patients. Divalproex was added to an ongoing neuroleptic in 10 patients, and 7 patients responded. Patients received a mean final divalproex dose of 1650 mg/day with a mean blood level of 64 microg/mL. Divalproex was well tolerated in this population except for reversible sedation in 8 patients and transient worsening gait and confusion in 1 subject. CONCLUSION: Divalproex appeared to be as effective as previously reported rates for neuroleptics in the treatment of behavioral disturbances in dementia. The combination of divalproex and a neuroleptic was effective in patients who had failed either agent administered independently.

Aged↗
PubMed1997

Safety and tolerability of the new antidepressants.

The newer serotonergic antidepressants have become popular particularly because of improved tolerability and safety. The evidence supporting this belief is reviewed. The factors that contribute to the development of somatic symptoms are examined, including the depression itself and the drugs used for treatment. The rates for individual side effects with the serotonin selective reuptake inhibitors, nefazodone, and venlafaxine are presented and compared with the adverse event experience for mirtazapine.

Antidepressive Agents, Second-Generation↗
PubMed1997

Treatment of refractory depression.

Treatment of refractory depression is a common challenge for mental health professionals. To assure optimal treatment, the clinician should first determine that adequate dosage has been employed for an adequate duration. Next there are a variety of augmentation strategies or alternative antidepressants that could be considered. This report reviews the evidence supporting these strategies, describes their implementation, compares their effectiveness, and offers suggestions for approaching the array of treatments available.

Antidepressive Agents↗
PubMed1996

Tetralogy of Fallot repair results in activation of the renin-angiotensin-aldosterone system.

Fluid retention is a common problem following transannular patch repair of tetralogy of Fallot. The present study was undertaken to evaluate whether humoral substances may contribute to this process. Patients undergoing tetralogy of Fallot repair using a transannular patch technique were compared to patients undergoing simple ventricular septal defect repair. Hormone levels were determined by radioimmunoassay. Fluid retention was defined as pleural effusions persisting beyond 5 days. The data demonstrate that patients undergoing tetralogy of Fallot repair had elevated levels of anti-diuretic hormone, renin, angiotensin II, and aldosterone as compared to a group with ventricular septal defect. The elevation in hormone levels in the tetralogy of Fallot group was principally accounted for by those who developed effusions postoperatively. These results suggest that activation of the renin angiotensin-aldosterone system may be one of the contributing factors to fluid retention following tetralogy of Fallot repair.

Aldosterone↗
PubMed1996

Analytical performance of free and total thyroxine assays.

Excessive bias and imprecision are major analytical problems associated with some assays for free and total thyroxine (T4). Bias in free T4 methods is largely proportional to variations in serum T4 binding. In direct methods, this is attributable to requirements for substantial quantities of protein-bound T4 to replace analytical losses of free T4. In some total T4 methods, bias is inversely proportional to the amount of serum T4 binding and is attributable to the incomplete release of serum protein-bound T4. In others, bias is fixed and attributable to inaccurate calibration. Manufacturers should report the bias in their methods. Calibrations should be standardized. Imprecision varies widely among methods, but is generally less for total T4 methods than for free T4 methods. A consensus on quantitative analytical performance goals for free and total T4 methods would be helpful. Here, performance goals are proposed, based in part on the best achievements of current methods.

Autoantibodies↗
PubMed1995

Comparative mapping in grasses. Oat relationships.

The development of RFLP linkage maps in hexaploid and diploid oat allows us to study genetic relationships of these species at the DNA level. In this report, we present the extension of a previously developed diploid oat map (Avena atlantica x A. hirtula) and its molecular-genetic relationships with wheat, rice and maize. Examination of 92-99% of the length of the oat genome map with probes common to Triticeae species, rice or maize showed that 84, 79 and 71%, respectively, was conserved between these species and oat. Generally, the orders of loci among chromosomes homoelogous to oat chromosomes A and D were the most conserved and those of chromosomes homoeologous to oat chromosome G were the least conserved. Conservation was observed for blocks ranging from whole chromosomes 101 cM long to small segments 2.5 cM long containing two loci. Comparison of the homoeologous segments of Triticeae, rice and maize relative to oat indicated that certain regions have been maintained in all four species. The relative positions of major genes governing traits such as seed storage proteins and resistance to leaf rusts have been conserved between cultivated oat and Triticeae species. Also, the locations of three vernalization/or photoperiod response genes identified in hexaploid oat correspond to the locations of similar genes in homoeologous chromosomes of wheat, rice or maize. The locations of the centromeres for six of the seven oat chromosomes were estimated based on the homoeologous segments between oat and Triticeae chromosomes.

Avena↗
PubMed1995

Comparative mapping in grasses. Wheat relationships.

Conventionally, the genetics of species of the family Gramineae have been studied separately. Comparative mapping using DNA markers offers a method of combining the research efforts in each species. In this study, we developed consensus maps for members of the Triticeae tribe (Triticum aestivum, T. tauschii, and Hordeum spp.) and compared them to rice, maize and oat. The aneuploid stocks available in wheat are invaluable for comparative mapping because almost every DNA fragment can be allocated to a chromosome arm, thus preventing erroneous conclusions about probes that could not be mapped due to a lack of polymorphism between mapping parents. The orders of the markers detected by probes mapped in rice, maize and oat were conserved for 93, 92 and 94% of the length of Triticeae consensus maps, respectively. The chromosome segments duplicated within the maize genome by ancient polyploidization events were identified by homoeology of segments from two maize chromosomes to regions of one Triticeae chromosome. Homoeologous segments conserved across Triticeae species, rice, maize, and oat can be identified for each Triticeae chromosome. Putative orthologous loci for several simply inherited and quantitatively inherited traits in Gramineae species were identified.

Avena↗
PubMed1995

Reference ranges for newer thyroid function tests in premature infants.

OBJECTIVE: To establish reference ranges for recently developed assays of thyroid function in premature infants. METHODS: We measured serum free thyroxine (T4) by direct equilibrium dialysis and serum thyrotropin by a sensitive immunometric method in 104 preterm infants (25 to 36 weeks of gestational age) during the first week of life. RESULTS: The free T4 level correlated positively with gestational age (p < 0.0001; r2 = 0.09) and differed significantly between adjacent gestational age groups (p < 0.05). Free T4 concentrations (mean +/- SD) for the 25- to 27-, 28-to 30-, 31- to 33-, and 34- to 36-week groups were 18.0 +/- 5.2, 25.7 +/- 9.0, 30.9 +/- 9.0, 36.0 +/- 10.3 pmol/L (1.4 +/- 0.4, 2.0 +/- 0.7, 2.8 +/- 0.8 ng/dl), respectively. Two reference ranges for free T4 were determined, one for 25 to 30 weeks (6.4 to 42.5 pmol/L (0.5 to 3.3 ng/dl) and one for 31 to 36 weeks (16.7 to 60.5 pmol/L (1.3 to 4.7 ng/dl)). The logarithm of the value for thyrotropin correlated positively with gestational age (p < 0.001; r2 = 0.08); one reference range of 0.5 to 29 mU/L was determined for thyrotropin. CONCLUSION: This study extends information on thyroid function of preterm infants and establishes reference ranges for this population.

Gestational Age↗
PubMed1995

Molecular mapping of wheat: major genes and rearrangements in homoeologous groups 4, 5, and 7.

A molecular-marker linkage map of hexaploid wheat (Triticum aestivum L. em. Thell) provides a framework for integration with teh classical genetic map and a record of the chromosomal rearrangements involved in the evolution of this crop species. We have constructed restriction fragment length polymorphism (RFLP) maps of the A-, B-, and D-genome chromosomes of homoeologous groups 4, 5, and 7 of wheat using 114 F7 lines from a synthetic X cultivated wheat cross and clones from 10 DNA libraries. Chromosomal breakpoints for known ancestral reciprocal translocations involving these chromosomes and for a known pericentric inversion on chromosome 4A were localized by linkage and aneuploid analysis. Known genes mapped include the major vernalization genes Vrn1 and Vrn3 on chromosome arms 5AL and 5DL, the red-coleoptile gene Rc1 on 7AS, and presumptively the leaf-rust (Puccinia recondita f.sp. tritici) resistance gene Lr34 on 7DS and the kernel-hardness gene Ha on 5DS. RFLP markers previously obtained for powdery-mildew (Blumeria graminis f.sp. tritici) resistance genes Pm2 and Pm1 were localized on chromosome arms 5DS and 7AL.

Chromosome Mapping↗
PubMed1995

Desipramine treatment of major depression in patients over 75 years of age.

The authors investigated the relationship of desipramine concentrations in plasma to response, side effects, and dose in depressed patients over 75 years of age to determine if these "very old" patients were unusually sensitive to treatment. Thirty-four elderly patients consecutively hospitalized for nonpsychotic, unipolar major depression were treated with a fixed dose desipramine regimen for 4 weeks. Twelve nonresponding patients received a second trial at an increased dose. Comparisons were made with data from younger patients previously published by the authors. At comparable doses, steady-state desipramine concentrations in plasma in the elderly patients did not differ from those observed in younger patients. Response at levels in blood < 115 ng/ml was low, only 6 (21%) of 28 patient trials resulted in response. At levels > or = 115 ng/ml, 6 (46%) of 13 patient trials were effective. These rates were not significantly different. Inspection of the data revealed that a concentration in plasma of 105 ng/ml significantly separated responders and nonresponders (chi 2 = 3.93, df = 1, p < 0.05), but even at levels > or = 105 ng/ml, the response rate was still low relative to rates in prior studies of younger patients treated for a similar duration. The serious adverse reaction rate, 7 of 34, was similar to that previously observed in younger patients. This sample of "very old" elderly was not unusually "sensitive" to antidepressant drug treatment. In fact, the low rate of response observed at usually adequate levels in blood suggested "resistance" to treatment. The findings underscore the need for more effective drug treatments in the depressed elderly.

Aged↗
PubMed1995

Renin, angiotensin II, and the development of effusions following bidirectional Glenn and Fontan procedures.

Pleural effusions are a troublesome complication following bidirectional Glenn and Fontan procedures. It was our hypothesis that effusions may be related to alterations in hormones that regulate fluid homeostasis. We made serial determinations (by radioimmunoassay) of antidiuretic hormone, cortisol, aldosterone, angiotensin II, and renin in patients undergoing bidirectional Glenn (n = 16) and Fontan procedures (n = 24). There were six patients who developed effusions following surgery. These patients had a different endocrinological pattern characterized by persistent elevation in renin (28 +/- 9 vs 9 +/- 5 ng/mL per hour, p < 0.01) and angiotensin II (110 +/- 33 vs 33 +/- 14 ng/L, p < 0.01) on the fifth postoperative day as compared to patients who did not develop effusions. These data demonstrate that patients who develop effusions following bidirectional Glenn and Fontan procedures have activation of their renin-angiotensin system.

Adolescent↗
PubMed1995

Assessment of extrapyramidal symptoms during acute neuroleptic treatment.

BACKGROUND: Acute administration of traditional neuroleptic drugs is often accompanied by the emergence of extrapyramidal symptoms (EPS). The use of a standardized scale to measure EPS can assist the clinician in assessing the occurrence and severity of these adverse reactions. The current work presents the interrater reliability and validity of the Yale Extrapyramidal Symptom Scale (YESS)--an eight-item, easy-to-administer scale for assessing emergence, severity, and type of side effects that commonly occur during acute treatment. METHOD: Interrater reliability (Study 1) and validity (Study 2) of the scale were studied using two independent samples of acutely psychotic patients treated with neuroleptic drugs. Study 1: Interrater reliability was assessed by comparing the YESS ratings of two clinicians blind to the other's rating and to the patient's drug regimen and dose. Study 2: Validity was studied by examining whether YESS items correlated with other EPS measures (convergent validity) but not with psychotic symptoms that may be confused with EPS (discriminant validity). RESULTS: Interrater agreement between clinicians was good to excellent. YESS items correlated with assessments used to measure symptoms of Parkinson's disease and akathisia and generally showed low nonsignificant correlations with ratings of symptoms of psychosis. CONCLUSION: The current work presents a brief EPS scale for the assessment of commonly occurring neuroleptic-induced extrapyramidal side effects. It was demonstrated that the YESS could be used reliably across clinician raters and that the YESS is a valid measure for assessing EPS during acute treatment.

Acute Disease↗
PubMed1994

Synaptic output of physiologically identified spiny stellate neurons in cat visual cortex.

Spiny stellate neurons of area 17 of the cat's visual cortex were physiologically characterised and injected intracellularly with horseradish peroxidase. Six neurons from sublamina 4A were selected. Five had the S-type of simple receptive fields; one had a complex receptive field. Their axons formed boutons mainly in layers 3 and 4. An electron microscopic examination of 45 boutons showed that each bouton formed one asymmetric synapse on average. Spines were the most frequent synaptic target (74%); dendritic shafts formed the remainder (26%). On the basis of ultrastructural characteristics, 8% of the target dendrites were characterised as originating from smooth gamma-aminobutyrate-ergic (GABAergic) neurons. Thus the major output of spiny stellate neurons is to other spiny neurons, probably pyramidal neurons in layer 3 and spiny stellates in layer 4.

Animals↗